Viewport Size Code:
Login | Create New Account


About | Classical Genetics | Timelines | What's New | What's Hot

About | Classical Genetics | Timelines | What's New | What's Hot


Bibliography Options Menu

Hide Abstracts   |   Hide Additional Links
Long bibliographies are displayed in blocks of 100 citations at a time. At the end of each block there is an option to load the next block.

Bibliography on: Symbiosis

The Electronic Scholarly Publishing Project: Providing world-wide, free access to classic scientific papers and other scholarly materials, since 1993.


ESP: PubMed Auto Bibliography 17 Sep 2021 at 01:36 Created: 


Symbiosis refers to an interaction between two or more different organisms living in close physical association, typically to the advantage of both. Symbiotic relationships were once thought to be exceptional situations. Recent studies, however, have shown that every multicellular eukaryote exists in a tight symbiotic relationship with billions of microbes. The associated microbial ecosystems are referred to as microbiome and the combination of a multicellular organism and its microbiota has been described as a holobiont. It seems "we are all lichens now."

Created with PubMed® Query: symbiosis NOT pmcbook NOT ispreviousversion

Citations The Papers (from PubMed®)


RevDate: 2021-09-15

Rosland NA, Ikhsan N, Min CC, et al (2021)

Influence of Symbiotic Probiont Strains on the Growth of Amphora and Chlorella and Its Potential Protections Against Vibrio spp. in Artemia.

Current microbiology [Epub ahead of print].

The emerging aquaculture industry is in need of non-antibiotic-based disease control approaches to minimize the risk of antibiotic-resistant bacteria. Bacterial infections mainly caused by Vibrio spp. have caused mass mortalities of fish especially during the larval stages. The objectives of this study were to verify the potential of symbiotic probiont strains, isolated from microalgae (Amphora, Chlorella, and Spirulina) for suppressing the growth of Vibrio spp. and at the same time ascertain their abilities to enhance microalgal biomass by mutualistic interactions through microalgae-bacteria symbiosis. In addition, in vivo studies on Artemia bioencapsulated with probiont strains (single strain and mix strains) and microalgae were evaluated. The selected potential probionts were identified as Lysinibacillus fusiformis strain A-1 (LFA-1), Bacillus sp. strain A-2 (BA-2), Lysinibacillus fusiformis strain Cl-3 (LFCl-3), and Bacillus pocheonensis strain S-2 (BPS-2) using 16s rRNA. The cell densities of Amphora culture supplemented with BA-2 and Chlorella culture supplemented with LFCl-3 were higher than those of the controls. Artemia bioencapsulated with mix strains (LFA-1 + BA-2 + LFCl-3 + BPS-2) and Amphora demonstrated the highest survival rate compared to the controls, after being challenged with V. harveyi (60 ± 4%) and V. parahaemolyticus (78 ± 2%). Our study postulated that BA-2 and LFCl-3 were found to be good promoting bacteria for microalgal growth and microalgae serve as a vector to transport probiotic into Artemia. Moreover, mixture of potential probionts is beneficial for Artemia supplementation in conferring protection to Artemia nauplii against pathogenic Vibrios.

RevDate: 2021-09-15

Jenkins BH, Maguire F, Leonard G, et al (2021)

Emergent RNA-RNA interactions can promote stability in a facultative phototrophic endosymbiosis.

Proceedings of the National Academy of Sciences of the United States of America, 118(38):.

Eukaryote-eukaryote endosymbiosis was responsible for the spread of chloroplast (plastid) organelles. Stability is required for the metabolic and genetic integration that drives the establishment of new organelles, yet the mechanisms that act to stabilize emergent endosymbioses-between two fundamentally selfish biological organisms-are unclear. Theory suggests that enforcement mechanisms, which punish misbehavior, may act to stabilize such interactions by resolving conflict. However, how such mechanisms can emerge in a facultative endosymbiosis has yet to be explored. Here, we propose that endosymbiont-host RNA-RNA interactions, arising from digestion of the endosymbiont population, can result in a cost to host growth for breakdown of the endosymbiosis. Using the model facultative endosymbiosis between Paramecium bursaria and Chlorella spp., we demonstrate that this mechanism is dependent on the host RNA-interference (RNAi) system. We reveal through small RNA (sRNA) sequencing that endosymbiont-derived messenger RNA (mRNA) released upon endosymbiont digestion can be processed by the host RNAi system into 23-nt sRNA. We predict multiple regions of shared sequence identity between endosymbiont and host mRNA, and demonstrate through delivery of synthetic endosymbiont sRNA that exposure to these regions can knock down expression of complementary host genes, resulting in a cost to host growth. This process of host gene knockdown in response to endosymbiont-derived RNA processing by host RNAi factors, which we term "RNAi collisions," represents a mechanism that can promote stability in a facultative eukaryote-eukaryote endosymbiosis. Specifically, by imposing a cost for breakdown of the endosymbiosis, endosymbiont-host RNA-RNA interactions may drive maintenance of the symbiosis across fluctuating ecological conditions.

RevDate: 2021-09-15
CmpDate: 2021-09-15

Wippel K, Tao K, Niu Y, et al (2021)

Host preference and invasiveness of commensal bacteria in the Lotus and Arabidopsis root microbiota.

Nature microbiology, 6(9):1150-1162.

Roots of different plant species are colonized by bacterial communities, that are distinct even when hosts share the same habitat. It remains unclear to what extent the host actively selects these communities and whether commensals are adapted to a specific plant species. To address this question, we assembled a sequence-indexed bacterial culture collection from roots and nodules of Lotus japonicus that contains representatives of most species previously identified using metagenomics. We analysed taxonomically paired synthetic communities from L. japonicus and Arabidopsis thaliana in a multi-species gnotobiotic system and detected signatures of host preference among commensal bacteria in a community context, but not in mono-associations. Sequential inoculation experiments revealed priority effects during root microbiota assembly, where established communities are resilient to invasion by latecomers, and that host preference of commensal bacteria confers a competitive advantage in their cognate host. Our findings show that host preference in commensal bacteria from diverse taxonomic groups is associated with their invasiveness into standing root-associated communities.

RevDate: 2021-09-15

Ledermann R, Schulte CCM, PS Poole (2021)

How Rhizobia Adapt to the Nodule Environment.

Journal of bacteriology, 203(12):e0053920.

Rhizobia are a phylogenetically diverse group of soil bacteria that engage in mutualistic interactions with legume plants. Although specifics of the symbioses differ between strains and plants, all symbioses ultimately result in the formation of specialized root nodule organs that host the nitrogen-fixing microsymbionts called bacteroids. Inside nodules, bacteroids encounter unique conditions that necessitate the global reprogramming of physiological processes and the rerouting of their metabolism. Decades of research have addressed these questions using genetics, omics approaches, and, more recently, computational modeling. Here, we discuss the common adaptations of rhizobia to the nodule environment that define the core principles of bacteroid functioning. All bacteroids are growth arrested and perform energy-intensive nitrogen fixation fueled by plant-provided C4-dicarboxylates at nanomolar oxygen levels. At the same time, bacteroids are subject to host control and sanctioning that ultimately determine their fitness and have fundamental importance for the evolution of a stable mutualistic relationship.

RevDate: 2021-09-14

Waterworth SC, Parker-Nance S, Kwan JC, et al (2021)

Comparative Genomics Provides Insight into the Function of Broad-Host Range Sponge Symbionts.

mBio [Epub ahead of print].

The fossil record indicates that the earliest evidence of extant marine sponges (phylum Porifera) existed during the Cambrian explosion and that their symbiosis with microbes may have begun in their extinct ancestors during the Precambrian period. Many symbionts have adapted to their sponge host, where they perform specific, specialized functions. There are also widely distributed bacterial taxa such as Poribacteria, SAUL, and Tethybacterales that are found in a broad range of invertebrate hosts. Here, we added 11 new genomes to the Tethybacterales order, identified a novel family, and show that functional potential differs between the three Tethybacterales families. We compare the Tethybacterales with the well-characterized Entoporibacteria and show that these symbionts appear to preferentially associate with low-microbial abundance (LMA) and high-microbial abundance (HMA) sponges, respectively. Within these sponges, we show that these symbionts likely perform distinct functions and may have undergone multiple association events, rather than a single association event followed by coevolution. IMPORTANCE Marine sponges often form symbiotic relationships with bacteria that fulfil a specific need within the sponge holobiont, and these symbionts are often conserved within a narrow range of related taxa. To date, there exist only three known bacterial taxa (Entoporibacteria, SAUL, and Tethybacterales) that are globally distributed and found in a broad range of sponge hosts, and little is known about the latter two. We show that the functional potential of broad-host range symbionts is conserved at a family level and that these symbionts have been acquired several times over evolutionary history. Finally, it appears that the Entoporibacteria are associated primarily with high-microbial abundance sponges, while the Tethybacterales associate with low-microbial abundance sponges.

RevDate: 2021-09-14

Qu Z, Zhang H, Wang Q, et al (2021)

Exploring the Symbiotic Mechanism of a Virus-Mediated Endophytic Fungus in Its Host by Dual Unique Molecular Identifier-RNA Sequencing.

mSystems [Epub ahead of print].

The symbiosis of endophytes and plants is universal in nature. However, how endophytes grow in plants is not entirely clear. Previously, we reported that a virus-infected fungal pathogen could grow in plants as an endophyte. In this study, we utilized Sclerotinia sclerotiorum strain DT-8, a virus-mediated endophyte, to investigate the mechanism of symbiosis with rapeseed by dual unique molecular identifier-RNA sequencing (dual-UMI RNA-seq). We found that the expressions of genes encoding S. sclerotiorum amylase/glucoamylase, glucose transporters, and rapeseed sugars will eventually be exported transporter 11 (SWEET11) were upregulated. It suggested that strain DT-8 might utilize plant starch as a nutrient. The defense systems of rapeseed were also activated, such as production of reactive oxygen species, phenylpropanoids, and brassinin, to control the growth of strain DT-8, while strain DT-8 counteracted host suppression by producing effector-like proteins, detoxification enzymes, and antioxidant components. Moreover, rapeseed also upregulated pectate lyase and pectinesterase genes to facilitate the colonization by strain DT-8. Our findings provide novel insights into the interaction of virus-mediated endophytes and their hosts that warrant further study. IMPORTANCE Although endophytes are widespread in nature, the interactions between endophytes and their hosts are still not fully understood. Members of a unique class of endophytes, the virus-mediated endophytic fungi, are continuously being discovered and have received wide attention. In this study, we investigated the interaction between a mycovirus-mediated endophytic fungus and its host rapeseed by using dual-UMI RNA-seq. According to the dual-UMI RNA-seq results, an aerial view of symbiotic mechanism under balanced regulation was suggested. This research expands our understanding of the symbiotic mechanisms of virus-fungus-plant interactions and could establish a foundation for the further development of practical application with virus-mediated hypovirulent fungi.

RevDate: 2021-09-14

Nagasawa M, T Kikusui (2021)

Neuroendocrine Mechanisms of Social Bonds and Separation Stress in Rodents, Dogs, and Other Species.

Current topics in behavioral neurosciences [Epub ahead of print].

Mammalian species form unique bonds between mothers and infants. Maternal care, including suckling, is necessary for infant survival, and the mother and, sometimes, the father require a lot of effort in nurturing infants. An infant's probability of survival depends on the extent of the investment of care by the mother. In parallel, mothers must identify their offspring and invest only in those who possess their genes to achieve evolutionary benefits. Therefore, they need to recognize their offspring and show a strong preference for them. For this reason, bond formation between mothers and infants is important. The mother monitors her offspring's physical condition and stays close to them. The offspring also form strong bonds with their mothers. Therefore, a separation between the mother and infant causes severe stress for both parties. Although it was initially thought that such bonds between mother and infant are limited to the same species, we have also observed a similar phenomenon in the human-dog relationship. In this article, we discuss the neuroendocrine mechanisms that underlie bond formation and separation based on findings of neurobiological research in mice and the relationship between humans and dogs.

RevDate: 2021-09-14
CmpDate: 2021-09-14

Bordon Y (2021)

Inner viruses ignite immunity to commensals.

Nature reviews. Immunology, 21(8):471.

RevDate: 2021-09-13

Aroney STN, Poole PS, C Sánchez-Cañizares (2021)

Rhizobial Chemotaxis and Motility Systems at Work in the Soil.

Frontiers in plant science, 12:725338.

Bacteria navigate their way often as individual cells through their chemical and biological environment in aqueous medium or across solid surfaces. They swim when starved or in response to physical and chemical stimuli. Flagella-driven chemotaxis in bacteria has emerged as a paradigm for both signal transduction and cellular decision-making. By altering motility, bacteria swim toward nutrient-rich environments, movement modulated by their chemotaxis systems with the addition of pili for surface movement. The numbers and types of chemoreceptors reflect the bacterial niche and lifestyle, with those adapted to complex environments having diverse metabolic capabilities, encoding far more chemoreceptors in their genomes. The Alpha-proteobacteria typify the latter case, with soil bacteria such as rhizobia, endosymbionts of legume plants, where motility and chemotaxis are essential for competitive symbiosis initiation, among other processes. This review describes the current knowledge of motility and chemotaxis in six model soil bacteria: Sinorhizobium meliloti, Agrobacterium fabacearum, Rhizobium leguminosarum, Azorhizobium caulinodans, Azospirillum brasilense, and Bradyrhizobium diazoefficiens. Although motility and chemotaxis systems have a conserved core, rhizobia possess several modifications that optimize their movements in soil and root surface environments. The soil provides a unique challenge for microbial mobility, since water pathways through particles are not always continuous, especially in drier conditions. The effectiveness of symbiont inoculants in a field context relies on their mobility and dispersal through the soil, often assisted by water percolation or macroorganism movement or networks. Thus, this review summarizes the factors that make it essential to consider and test rhizobial motility and chemotaxis for any potential inoculant.

RevDate: 2021-09-13

Goddard ML, Belval L, Martin IR, et al (2021)

Arbuscular Mycorrhizal Symbiosis Triggers Major Changes in Primary Metabolism Together With Modification of Defense Responses and Signaling in Both Roots and Leaves of Vitis vinifera.

Frontiers in plant science, 12:721614.

Grapevine (Vitis vinifera L.) is one of the most important crops worldwide but is subjected to multiple biotic and abiotic stresses, especially related to climate change. In this context, the grapevine culture could take advantage of symbiosis through association with arbuscular mycorrhizal fungi (AMF), which are able to establish symbiosis with most terrestrial plants. Indeed, it is well established that mycorrhization improves grapevine nutrition and resistance to stresses, especially water stress and resistance to root pathogens. Thus, it appears essential to understand the effect of mycorrhization on grapevine metabolism and defense responses. In this study, we combined a non-targeted metabolomic approach and a targeted transcriptomic study to analyze changes induced in both the roots and leaves of V. vinifera cv. Gewurztraminer by colonization with Rhizophagus irregularis (Ri). We showed that colonization of grapevine with AMF triggers major reprogramming of primary metabolism in the roots, especially sugar and fatty acid metabolism. On the other hand, mycorrhizal roots had decreased contents of most sugars and sugar acids. A significant increase in several fatty acids (C16:1, linoleic and linolenic acids and the C20 arachidonic and eicosapentaenoic acids) was also detected. However, a downregulation of the JA biosynthesis pathway was evidenced. We also found strong induction of the expression of PR proteins from the proteinase inhibitor (PR6) and subtilase (PR7) families in roots, suggesting that these proteins are involved in the mycorrhiza development but could also confer higher resistance to root pathogens. Metabolic changes induced by mycorrhization were less marked in leaves but involved higher levels of linoleic and linolenic acids and decreased sucrose, quinic, and shikimic acid contents. In addition, Ri colonization resulted in enhanced JA and SA levels in leaves. Overall, this study provides a detailed picture of metabolic changes induced by AMF colonization in a woody, economically important species. Moreover, stimulation of fatty acid biosynthesis and PR protein expression in roots and enhanced defense hormone contents in leaves establish first insight in favor of better resistance of grapevine to various pathogens provided by AMF colonization.

RevDate: 2021-09-13

Nesbitt H, Burke C, M Haghi (2021)

Manipulation of the Upper Respiratory Microbiota to Reduce Incidence and Severity of Upper Respiratory Viral Infections: A Literature Review.

Frontiers in microbiology, 12:713703.

There is a high incidence of upper respiratory viral infections in the human population, with infection severity being unique to each individual. Upper respiratory viruses have been associated previously with secondary bacterial infection, however, several cross-sectional studies analyzed in the literature indicate that an inverse relationship can also occur. Pathobiont abundance and/or bacterial dysbiosis can impair epithelial integrity and predispose an individual to viral infection. In this review we describe common commensal microorganisms that have the capacity to reduce the abundance of pathobionts and maintain bacterial symbiosis in the upper respiratory tract and discuss the potential and limitations of localized probiotic formulations of commensal bacteria to reduce the incidence and severity of viral infections.

RevDate: 2021-09-13

He X, Xie H, Gao D, et al (2021)

Biochar and Intercropping With Potato-Onion Enhanced the Growth and Yield Advantages of Tomato by Regulating the Soil Properties, Nutrient Uptake, and Soil Microbial Community.

Frontiers in microbiology, 12:695447.

The application of biochar stimulates the activities of microorganisms that affect soil quality and plant growth. However, studies on the impacts of biochar mainly focus on a monoculture, its effects on interspecific interactions are rarely reported. Here, we investigated the impacts of biochar on tomato/potato-onion intercropped (TO) in a pot experiment. Tomato monoculture (T) and TO were treated with no, 0.3, 0.6, and 1.2% biochar concentrations in a pot experiment. Microbial communities from tomato rhizosphere soil were analyzed by quantitative PCR and Illumina MiSeq. The results showed that compared with the tomato monoculture, 0.6%TO and 1.2%TO significantly increased tomato yield in 2018. TO and 1.2%TO significantly increased plant height and dry weight in 2018 and 2019. Biochar treatments increased soil pH, decreased NO 3 - -N and bulk density, and increased the absorption of N, P, and K by tomato. Bacterial and fungal abundances increased with an increase in biochar concentration, while Bacillus spp. and Pseudomonas spp. abundances showed an "increase-decrease-increase" trend. Biochar had a little effect on bacterial diversities but significantly lowered fungal diversities. TO, 0.6%TO, and 1.2%TO increased the potentially beneficial organisms (e.g., Pseudeurotium and Solirubrobacter) and lowered the potentially pathogenic organisms (e.g., Kribbella and Ilyonectria). Different concentrations of biochar affected the bacterial and fungal community structures. Redundancy analysis indicated that the bacterial community was strongly correlated with soil pH, NO 3 - -N, and EC, while the fungal community was closely related to soil NO 3 - -N and moisture. The network analysis showed that biochar and intercropping affected the symbiosis pattern of the microorganisms and increased the proportion of positive interactions and nitrifying microorganisms (Nitrospirae) in the microbial community. Overall, our results indicated that monoculture and intercropping with biochar improved soil physicochemical states and plant nutrient absorption, and regulated soil microbial communities, these were the main factors to promote tomato growth and increase tomato productivity.

RevDate: 2021-09-13

Kise H, Obuchi M, JD Reimer (2021)

A new Antipathozoanthus species (Cnidaria, Hexacorallia, Zoantharia) from the northwest Pacific Ocean.

ZooKeys, 1040:49-64 pii:62309.

A new species of zoantharian within the genus Antipathozoanthus is described based on specimens collected from the coast of mainland Japan, northwest Pacific Ocean. Antipathozoanthustubus sp. nov. is characterized by its substrate (epibiotic on polychaete tube) and habitat (exposed rock). As well, the results of molecular phylogenetic analyses using concatenated multiple genetic markers also support the distinction between A.tubus sp. nov. and its congenerics. Antipathozoanthustubus sp. nov. is the first species of Antipathozoanthus species reported to be epibiotic on polychaete tubes, and is the second species in the genus that is not associated with antipatharians.

RevDate: 2021-09-13

Chen X, Hu A, Zou Q, et al (2021)

The Mesorhizobium huakuii transcriptional regulator AbiEi plays a critical role in nodulation and is important for bacterial stress response.

BMC microbiology, 21(1):245.

BACKGROUND: Bacterial abortive infection (Abi) systems are type IV toxin-antitoxin (TA) system, which could elicit programmed cell death and constitute a native survival strategy of pathogenic bacteria under various stress conditions. However, no rhizobial AbiE family TA system has been reported so far. Here, a M. huakuii AbiE TA system was identified and characterized.

RESULTS: A mutation in M. huakuii abiEi gene, encoding an adjacent GntR-type transcriptional regulator, was generated by homologous recombination. The abiEi mutant strain grew less well in rich TY medium, and displayed increased antioxidative capacity and enhanced gentamicin resistance, indicating the abiEi operon was negatively regulated by the antitoxin AbiEi in response to the oxidative stress and a particular antibiotic. The mRNA expression of abiEi gene was significantly up-regulated during Astragalus sinicus nodule development. The abiEi mutant was severely impaired in its competitive ability in rhizosphere colonization, and was defective in nodulation with 97% reduction in nitrogen-fixing capacity. The mutant infected nodule cells contained vacuolation and a small number of abnormal bacteroids with senescence character. RNA-seq experiment revealed it had 5 up-regulated and 111 down-regulated genes relative to wild type. Of these down-regulated genes, 21 are related to symbiosis nitrogen fixation and nitrogen mechanism, 16 are involved in the electron transport chain and antioxidant responses, and 12 belong to type VI secretion system (T6SS).

CONCLUSIONS: M. huakuii AbiEi behaves as a key transcriptional regulator mediating root nodule symbiosis.

RevDate: 2021-09-12

Rangel LI, Hamilton O, de Jonge R, et al (2021)

Fungal social influencers: secondary metabolites as a platform for shaping the plant-associated community.

The Plant journal : for cell and molecular biology [Epub ahead of print].

Fungal secondary metabolites (FSMs) are capable of manipulating plant community dynamics by inhibiting or facilitating the establishment of co-habitating organisms. Although production of FSMs is not crucial for survival of the producer, their absence can indirectly impair growth and/or niche competition of these fungi on the plant. Presence of FSMs with no obvious consequence on the fitness of the producer leaves questions regarding ecological impact. This review investigates how fungi employ FSMs as a platform to mediate fungal-fungal, fungal-bacterial, and fungal-animal interactions associated with the plant community. We discuss how the biological function of FSMs may indirectly benefit the producer by altering the dynamics of surrounding organisms. We introduce several instances where FSMs influence antagonistic- or alliance-driven interactions. Part of our aim is to decipher the meaning of the FSM 'language' since it is widely noted to impact the surrounding community. Here, we highlight the contribution of FSMs to plant-associated interaction networks that affect the host either broadly or in ways that may have previously been unclear.

RevDate: 2021-09-12

Pereira AM, A Clemente (2021)

Dogs' microbiome from tip to toe.

Topics in companion animal medicine pii:S1938-9736(21)00077-5 [Epub ahead of print].

Microbiota and microbiome, which refers, respectively, to the microorganisms and conjoint of microorganisms and genes are known to live in symbiosis with hosts, being implicated in health and disease. The advancements and cost reduction associated with high-throughput sequencing techniques have allowed expanding the knowledge of microbial communities in several species, including dogs. Throughout their body, dogs harbor distinct microbial communities according to the location (e.g., skin, ear canal, conjunctiva, respiratory tract, genitourinary tract, gut), which have been a target of study mostly in the last couple of years. Although there might be a core microbiota for different body sites, shared by dogs, it is likely influenced by intrinsic factors such as age, breed, and sex, but also by extrinsic factors such as the environment (e.g., lifestyle, urban vs rural), and diet. It starts to become clear that some medical conditions are mediated by alterations in microbiota namely dysbiosis. Moreover, understanding microbial colonization and function can be used to prevent medical conditions, for instance, modulation of gut microbiota of puppies is more effective to ensure a healthy gut than interventions in adults. This paper gathers current knowledge of dogs' microbial communities, exploring their function, implications in the development of diseases, and potential interactions among communities while providing hints for further research.

RevDate: 2021-09-13
CmpDate: 2021-09-13

Ióca LP, Dai Y, Kunakom S, et al (2021)

A Family of Nonribosomal Peptides Modulate Collective Behavior in Pseudovibrio Bacteria Isolated from Marine Sponges*.

Angewandte Chemie (International ed. in English), 60(29):15891-15898.

Although swarming motility and biofilms are opposed collective behaviors, both contribute to bacterial survival and host colonization. Pseudovibrio bacteria have attracted attention because they are part of the microbiome of healthy marine sponges. Two-thirds of Pseudovibrio genomes contain a member of a nonribosomal peptide synthetase-polyketide synthase gene cluster family, which is also found sporadically in Pseudomonas pathogens of insects and plants. After developing reverse genetics for Pseudovibrio, we isolated heptapeptides with an ureido linkage and related nonadepsipeptides we termed pseudovibriamides A and B, respectively. A combination of genetics and imaging mass spectrometry experiments showed heptapetides were excreted, promoting motility and reducing biofilm formation. In contrast to lipopeptides widely known to affect motility/biofilms, pseudovibriamides are not surfactants. Our results expand current knowledge on metabolites mediating bacterial collective behavior.

RevDate: 2021-09-13
CmpDate: 2021-09-13

Maeda T, Takahashi S, Yoshida T, et al (2021)

Chloroplast acquisition without the gene transfer in kleptoplastic sea slugs, Plakobranchus ocellatus.

eLife, 10:.

Some sea slugs sequester chloroplasts from algal food in their intestinal cells and photosynthesize for months. This phenomenon, kleptoplasty, poses a question of how the chloroplast retains its activity without the algal nucleus. There have been debates on the horizontal transfer of algal genes to the animal nucleus. To settle the arguments, this study reported the genome of a kleptoplastic sea slug, Plakobranchus ocellatus, and found no evidence of photosynthetic genes encoded on the nucleus. Nevertheless, it was confirmed that light illumination prolongs the life of mollusk under starvation. These data presented a paradigm that a complex adaptive trait, as typified by photosynthesis, can be transferred between eukaryotic kingdoms by a unique organelle transmission without nuclear gene transfer. Our phylogenomic analysis showed that genes for proteolysis and immunity undergo gene expansion and are up-regulated in chloroplast-enriched tissue, suggesting that these molluskan genes are involved in the phenotype acquisition without horizontal gene transfer.

RevDate: 2021-09-13
CmpDate: 2021-09-13

Lee J, Davidson TM, ME Torchin (2021)

Variable host responses mediate host preference in marine flatworm-snail symbioses.

PloS one, 16(3):e0247551.

Host preference of symbionts evolves from fitness trade-offs. However, it is often unclear how interspecific variations in host response traits influence this evolutionary process. Using the association between the polyclad flatworm Paraprostatum echinolittorinae and its intertidal snail hosts on the Pacific Coast of Panama, we assessed how a symbiont's host preference is associated with varying host defenses and post-infestation performances. We first characterized the prevalence and intensity of worm infestation in five snail hosts (Tegula pellisserpentis, Nerita scabricosta, N. funiculata, Planaxis planicostatus, and Cerithium stercusmuscarum). We then used manipulative experiments to test flatworm's host choice, hosts' behavioral rejection of flatworms, and hosts' growth and survival following the infestation. In the field, flatworms were orders of magnitude more prevalent and dense in T. pellisserpentis, N. scabricosta, N. funiculata than P. planicostatus and C. stercusmuscarum, although the three former hosts were not necessarily more abundant. The results from our laboratory host selection trials mirrored these patterns; flatworms were 3 to 14 times more likely to choose T. pellisserpentis, N. scabricosta, N. funiculata over P. planicostatus and C. stercusmuscarum. The less preferred hosts frequently rejected flatworms via mantle contractions and foot withdrawals, which reduced the infestation rate by 39%-67%. These behaviors were less frequent or absent in the preferred hosts. Flatworm infestation variably influenced host performances in the field, negligibly affecting the growth and survival of T. pellisserpentis and N. funiculata but reducing the growth of P. planicostatus. Flatworms thus preferred less defended hosts that can also support higher worm densities without being harmed. Stable isotope analysis further revealed that flatworms are unlikely to feed on snail tissues and may live as a commensal in their preferred hosts. Our study demonstrates that host response traits can modulate a symbiont's host choice and calls for more explicit considerations of host response variability in host preference research.

RevDate: 2021-09-13
CmpDate: 2021-09-13

Khalmuratova I, Choi DH, Yoon HJ, et al (2021)

Diversity and Plant Growth Promotion of Fungal Endophytes in Five Halophytes from the Buan Salt Marsh.

Journal of microbiology and biotechnology, 31(3):408-418.

The diversity and plant growth-promoting ability of fungal endophytes that are associated with five halophytic plant species (Phragmites australis, Suaeda australis, Limonium tetragonum, Suaeda glauca Bunge, and Suaeda maritima) growing in the Buan salt marsh on the west coast of South Korea have been explored. About 188 fungal strains were isolated from these plant samples' roots and were then studied with the use of the internal transcribed spacer (ITS) region (ITS1-5.8S-ITS2). The endophytic fungal strains belonged to 33 genera. Alternaria (18%) and Fusarium (12.8%), of the classes Dothideomycetes and Sordariomycetes, were most rampant in the coastal salt marsh plants. There was a higher diversity in fungal endophytes that are isolated from S. glauca Bunge than in isolates from other coastal salt marsh plants. Plant growth-promoting experiments with the use of Waito-C rice seedlings show that some of the fungal strains could encourage a more efficient growth than others. Furthermore, gibberellins (GAs) GA1, GA3, and GA9 were seen in the Sa-1-4-3 isolate (Acrostalagmus luteoalbus) culture filtrate with a gas chromatography/mass spectrometry.

RevDate: 2021-09-13
CmpDate: 2021-09-13

Na H, Jo SW, Do JM, et al (2021)

Production of Algal Biomass and High-Value Compounds Mediated by Interaction of Microalgal Oocystis sp. KNUA044 and Bacterium Sphingomonas KNU100.

Journal of microbiology and biotechnology, 31(3):387-397.

There is growing interest in the production of microalgae-based, high-value by-products as an emerging green biotechnology. However, a cultivation platform for Oocystis sp. has yet to be established. We therefore examined the effects of bacterial culture additions on the growth and production of valuable compounds of the microalgal strain Oocystis sp. KNUA044, isolated from a locally adapted region in Korea. The strain grew only in the presence of a clear supernatant of Sphingomonas sp. KNU100 culture solution and generated 28.57 mg/l/d of biomass productivity. Protein content (43.9 wt%) was approximately two-fold higher than carbohydrate content (29.4 wt%) and lipid content (13.9 wt%). Oocystis sp. KNUA044 produced the monosaccharide fucose (33 μg/mg and 0.94 mg/l/d), reported here for the first time. Fatty acid profiling showed high accumulation (over 60%) of polyunsaturated fatty acids (PUFAs) compared to saturated (29.4%) and monounsaturated fatty acids (9.9%) under the same culture conditions. Of these PUFAs, the algal strain produced the highest concentration of linolenic acid (C18:3 ω3; 40.2%) in the omega-3 family and generated eicosapentaenoic acid (C20:5 ω3; 6.0%), also known as EPA. Based on these results, we suggest that the application of Sphingomonas sp. KNU100 for strain-dependent cultivation of Oocystis sp. KNUA044 holds future promise as a bioprocess capable of increasing algal biomass and high-value bioactive by-products, including fucose and PUFAs such as linolenic acid and EPA.

RevDate: 2021-09-11

Xi L, Shen Y, Zhao X, et al (2021)

Effects of arbuscular mycorrhizal fungi on frond antimony enrichment, morphology, and proteomics in Pteris cretica var. nervosa during antimony phytoremediation.

The Science of the total environment, 804:149904 pii:S0048-9697(21)04979-2 [Epub ahead of print].

Pteris cretica var. nervosa is a dominant fern species found in antimony (Sb) mining areas, capable of forming symbiosis with arbuscular mycorrhizal fungi (AMF), especially with those members of the Glomus genus. Despite this fern's relevance and the potential contribution of mycorrhizal symbiosis to phytoremediation, the AMF's impact on P. var. nervosa phytoremediation of Sb remains unknown. Here, we exposed P. var. nervosa to different concentrations of Sb for 6 months. Our results showed that Sb reduced shoot biomass, enlarged the root/shoot ratio, and disrupted the fronds' intracellular structure. AMF inoculation, however, was able to moderate these phenotypic changes and increased the accumulation level of Sb in plants. From a proteomics analysis of this plant's fronds, a total of 283 proteins were identified. Notably, those proteins with catalytic function, carbon fixing and ATP metabolic function were highly enriched. K-means clustering demonstrated protein-changing patterns involved in multiple metabolic pathways during exposure to Sb. Further, these patterns can be moderated by AMF inoculation. Pearson correlations were used to assess the plant biomarkers-soil Sb relationships; This revealed a strong correlation between ribosome alteration and the root/shoot ratio when inoculated with AMF, and a positive correlation between photosynthesis proteins and chlorophyll (SPAD value). Our results indicate AMF could moderate the fronds impairment by maintaining the sufficient protein levels for ribosomal functioning, photosynthesis activity and to counter ROS production. We demonstrate the effective use of AMF associated with P. cretica var. nervosa for Sb phytoremediation and the potential of applying proteomics to better understand the mechanism behind this symbiotic plant physiological response.

RevDate: 2021-09-11

van de Guchte M, Mondot S, J Doré (2021)

Dynamic properties of the intestinal ecosystem call for combination therapies, targeting inflammation and microbiota, in ulcerative colitis.

Gastroenterology pii:S0016-5085(21)03482-X [Epub ahead of print].

BACKGROUND AND AIMS: Intestinal microbiota - host interactions play a major role in health and disease. This has been documented at the microbiota level ("dysbiosis" in chronic immune-mediated diseases) and through the study of specific bacteria - host interactions, but rarely at the level of intestinal ecosystem dynamics. Yet, understanding the behavior of this ecosystem may be key to the successful treatment of disease. We recently postulated that health and disease represent alternative stable states of the intestinal ecosystem (different configurations that can exist under identical external conditions), which would demand for adapted strategies in disease treatment. Here, we examine if alternative stable states indeed exist in this ecosystem, and if they could affect remission from ulcerative colitis (UC).

METHODS: We analyzed data from a study on pediatric UC. The data reflect current treatment practice following the recruitment of new-onset, treatment-naïve, patients. Patients received personalized anti-inflammatory treatments over a period of one year. Stool samples at 0, 4, 12 and 52 weeks allowed an estimation of microbiota status (through 16S rRNA gene sequencing) and host inflammatory status (through the measurement of fecal calprotectin levels).

RESULTS: We identify four microbiota states and four host states. Longitudinal data show that the improvement of inflammatory status is accompanied by an improvement of microbiota status. However, they also provide strong indications that both improvements are retarded or blocked by alternative states barriers.

CONCLUSIONS: Our observations strongly suggest that inflammation suppression should be combined with microbiota management where possible to improve the efficacy of UC treatment.

RevDate: 2021-09-10

Xu S, Chen J, Qin M, et al (2021)

Geography-dependent symbiont communities in two oligophagous aphid species.

FEMS microbiology ecology pii:6368335 [Epub ahead of print].

Aphids and their diverse symbionts have become a good model to study bacteria-arthropod symbiosis. The feeding habits of aphids are usually influenced by a variety of symbionts. Most studies on symbiont diversity have focused on polyphagous aphids, while symbiont community patterns for oligophagous aphids remain unclear. Here, we surveyed the bacterial communities in natural populations of two oligophagous aphids, Melanaphis sacchari and Neophyllaphis podocarpi, in natural populations. Seven common symbionts were detected, among which Buchnera aphidicola and Wolbachia were the most prevalent. In addition, an uncommon Sodalis-like symbiont was also detected in these two aphids, and Gilliamella was found in some samples of M. sacchari. We further assessed the significant variation in symbiont communities within the two aphid species, geographical regions and host specialization using statistical and ordination analyses. Geography was an important factor in shaping the symbiont community structure in these oligophagous aphids. Furthermore, the strong geographical influence may be related to specific environmental factors, especially temperature, among different regions. These findings extend our knowledge of the significance of geography and its associated environmental conditions in the symbiont community structure associated with oligophagous aphids.

RevDate: 2021-09-10

Preethish-Kumar V, Shah A, Polavarapu K, et al (2021)

Disrupted structural connectome and neurocognitive functions in Duchenne muscular dystrophy: classifying and subtyping based on Dp140 dystrophin isoform.

Journal of neurology [Epub ahead of print].

OBJECTIVE: Neurocognitive disabilities in Duchenne muscular dystrophy (DMD) children beginning in early childhood and distal DMD gene deletions involving disruption of Dp140 isoform are more likely to manifest significant neurocognitive impairments. MRI data analysis techniques like brain-network metrics can provide information on microstructural integrity and underlying pathophysiology.

METHODS: A prospective study on 95 participants [DMD = 57, and healthy controls (HC) = 38]. The muscular dystrophy functional rating scale (MDFRS) scores, neuropsychology batteries, and multiplex ligand-dependent probe amplification (MLPA) testing were used for clinical assessment, IQ estimation, and genotypic classification. Diffusion MRI and network-based statistics were used to analyze structural connectomes at various levels and correlate with clinical markers.

RESULTS: Motor and executive sub-networks were extracted and analyzed. Out of 57 DMD children, 23 belong to Dp140 + and 34 to Dp140- subgroup. Motor disabilities are pronounced in Dp140- subgroup as reflected by lower MDFRS scores. IQ parameters are significantly low in all-DMD cases; however, the Dp140- has specifically lowest scores. Significant differences were observed in global efficiency, transitivity, and characteristic path length between HC and DMD. Subgroup analysis demonstrates that the significance is mainly driven by participants with Dp140- than Dp140 + isoform. Finally, a random forest classifier model illustrated an accuracy of 79% between HC and DMD and 90% between DMD- subgroups.

CONCLUSIONS: Current findings demonstrate structural network-based characterization of abnormalities in DMD, especially prominent in Dp140-. Our observations suggest that participants with Dp140 + have relatively intact connectivity while Dp140- show widespread connectivity alterations at global, nodal, and edge levels. This study provides valuable insights supporting the genotype-phenotype correlation of brain-behavior involvement in DMD children.

RevDate: 2021-09-10

Kiefer JST, Batsukh S, Bauer E, et al (2021)

Author Correction: Inhibition of a nutritional endosymbiont by glyphosate abolishes mutualistic benefit on cuticle synthesis in Oryzaephilus surinamensis.

Communications biology, 4(1):1079.

RevDate: 2021-09-10

Büttner H, Niehs SP, Vandelannoote K, et al (2021)

Bacterial endosymbionts protect beneficial soil fungus from nematode attack.

Proceedings of the National Academy of Sciences of the United States of America, 118(37):.

Fungi of the genus Mortierella occur ubiquitously in soils where they play pivotal roles in carbon cycling, xenobiont degradation, and promoting plant growth. These important fungi are, however, threatened by micropredators such as fungivorous nematodes, and yet little is known about their protective tactics. We report that Mortierella verticillata NRRL 6337 harbors a bacterial endosymbiont that efficiently shields its host from nematode attacks with anthelmintic metabolites. Microscopic investigation and 16S ribosomal DNA analysis revealed that a previously overlooked bacterial symbiont belonging to the genus Mycoavidus dwells in M. verticillata hyphae. Metabolic profiling of the wild-type fungus and a symbiont-free strain obtained by antibiotic treatment as well as genome analyses revealed that highly cytotoxic macrolactones (CJ-12,950 and CJ-13,357, syn necroxime C and D), initially thought to be metabolites of the soil-inhabiting fungus, are actually biosynthesized by the endosymbiont. According to comparative genomics, the symbiont belongs to a new species (Candidatus Mycoavidus necroximicus) with 12% of its 2.2 Mb genome dedicated to natural product biosynthesis, including the modular polyketide-nonribosomal peptide synthetase for necroxime assembly. Using Caenorhabditis elegans and the fungivorous nematode Aphelenchus avenae as test strains, we show that necroximes exert highly potent anthelmintic activities. Effective host protection was demonstrated in cocultures of nematodes with symbiotic and chemically complemented aposymbiotic fungal strains. Image analysis and mathematical quantification of nematode movement enabled evaluation of the potency. Our work describes a relevant role for endofungal bacteria in protecting fungi against mycophagous nematodes.

RevDate: 2021-09-10
CmpDate: 2021-09-10

Yoshida S, YJ Kee (2021)

Large-scale sequencing paves the way for genomic and genetic analyses in parasitic plants.

Current opinion in biotechnology, 70:248-254.

Parasitic plants pose a serious agricultural threat, but are also precious resources for valuable metabolites. The heterotrophic nature of these plants has resulted in the development of several morphological and physiological features that are of evolutionary significance. Recent advances in large-scale sequencing technology have provided insights into the evolutionary and molecular mechanisms of plant parasitism. Genome sequencing has revealed gene losses and horizontal gene transfers in parasitic plants. Mobile signals traveling between the parasite and host may have contributed to the increased fitness of parasitic life styles. Transcriptome analyses implicate shared processes among various parasitic species and the establishment of functional analysis is beginning to reveal molecular mechanisms during host and parasite interactions.

RevDate: 2021-09-10
CmpDate: 2021-09-10

Duchenne F, Fontaine C, Teulière E, et al (2021)

Phenological traits foster persistence of mutualistic networks by promoting facilitation.

Ecology letters, 24(10):2088-2099.

Morphological and phenological traits are key determinants of the structure of mutualistic networks. Both traits create forbidden links, but phenological traits can also decouple interaction in time. While such difference likely affects the indirect effects among species and consequently network persistence, it remains overlooked. Here, using a dynamic model, we show that networks structured by phenology favour facilitation over competition within guilds of pollinators and plants, thereby increasing network persistence, while the contrary holds for networks structured by morphology. We further show that such buffering of competition by phenological traits mostly beneficiate to specialists, the most vulnerable species otherwise, which propagate the most positive effects within guilds and promote nestedness. Our results indicate that beyond trophic mismatch, phenological shifts such as those induced by climate change are likely to affect indirect effects within mutualistic assemblages, with consequences for biodiversity.

RevDate: 2021-09-09

Decelle J, Veronesi G, LeKieffre C, et al (2021)

Subcellular architecture and metabolic connection in the planktonic photosymbiosis between Collodaria (radiolarians) and their microalgae.

Environmental microbiology [Epub ahead of print].

Photosymbiosis is widespread and ecologically important in the oceanic plankton but remains poorly studied. Here, we used multimodal subcellular imaging to investigate the photosymbiosis between colonial Collodaria and their microalga dinoflagellate (Brandtodinium). We showed that this symbiosis is very dynamic whereby symbionts interact with different host cells via extracellular vesicles within the colony. 3D electron microscopy revealed that the photosynthetic apparatus of the microalgae was more voluminous in symbiosis compared to free-living while the mitochondria volume was similar. Stable isotope probing coupled with NanoSIMS showed that carbon and nitrogen were stored in the symbiotic microalga in starch granules and purine crystals, respectively. Nitrogen was also allocated to the algal nucleolus. In the host, low 13 C transfer was detected in the Golgi. Metal mapping revealed that intracellular iron concentration was similar in free-living and symbiotic microalgae (ca 40 ppm) and two-fold higher in the host, whereas copper concentration increased in symbionts and was detected in the host cell and extracellular vesicles. Sulfur concentration was around two times higher in symbionts (chromatin and pyrenoid) than their host. This study improves our understanding on the functioning of this oceanic photosymbiosis and paves the way for more studies to further assess its biogeochemical significance. This article is protected by copyright. All rights reserved.

RevDate: 2021-09-09
CmpDate: 2021-09-09

Epihov DZ, Saltonstall K, Batterman SA, et al (2021)

Legume-microbiome interactions unlock mineral nutrients in regrowing tropical forests.

Proceedings of the National Academy of Sciences of the United States of America, 118(11):.

Legume trees form an abundant and functionally important component of tropical forests worldwide with N2-fixing symbioses linked to enhanced growth and recruitment in early secondary succession. However, it remains unclear how N2-fixers meet the high demands for inorganic nutrients imposed by rapid biomass accumulation on nutrient-poor tropical soils. Here, we show that N2-fixing trees in secondary Neotropical forests triggered twofold higher in situ weathering of fresh primary silicates compared to non-N2-fixing trees and induced locally enhanced nutrient cycling by the soil microbiome community. Shotgun metagenomic data from weathered minerals support the role of enhanced nitrogen and carbon cycling in increasing acidity and weathering. Metagenomic and marker gene analyses further revealed increased microbial potential beneath N2-fixers for anaerobic iron reduction, a process regulating the pool of phosphorus bound to iron-bearing soil minerals. We find that the Fe(III)-reducing gene pool in soil is dominated by acidophilic Acidobacteria, including a highly abundant genus of previously undescribed bacteria, Candidatus Acidoferrum, genus novus. The resulting dependence of the Fe-cycling gene pool to pH determines the high iron-reducing potential encoded in the metagenome of the more acidic soils of N2-fixers and their nonfixing neighbors. We infer that by promoting the activities of a specialized local microbiome through changes in soil pH and C:N ratios, N2-fixing trees can influence the wider biogeochemical functioning of tropical forest ecosystems in a manner that enhances their ability to assimilate and store atmospheric carbon.

RevDate: 2021-09-07
CmpDate: 2021-09-07

Dang H, Zhang T, Li G, et al (2020)

Root-associated endophytic bacterial community composition and structure of three medicinal licorices and their changes with the growing year.

BMC microbiology, 20(1):291.

BACKGROUND: The dried roots and rhizomes of medicinal licorices are widely used worldwide as a traditional medicinal herb, which are mainly attributed to a variety of bioactive compounds that can be extracted from licorice root. Endophytes and plants form a symbiotic relationship, which is an important source of host secondary metabolites.

RESULTS: In this study, we used high-throughput sequencing technology and high-performance liquid chromatography to explore the composition and structure of the endophytic bacterial community and the content of bioactive compounds (glycyrrhizic acid, liquiritin and total flavonoids) in different species of medicinal licorices (Glycyrrhiza uralensis, Glycyrrhiza glabra, and Glycyrrhiza inflata) and in different planting years (1-3 years). Our results showed that the contents of the bioactive compounds in the roots of medicinal licorices were not affected by the species, but were significantly affected by the main effect growing year (1-3) (P < 0.05), and with a trend of stable increase in the contents observed with each growing year. In 27 samples, a total of 1,979,531 effective sequences were obtained after quality control, and 2432 effective operational taxonomic units (OTUs) were obtained at 97% identity. The phylum Proteobacteria, Actinobacteria, Bacteroidetes and Firmicutes, and the genera unified-Rhizobiaceae, Pseudomonas, Novosphingobium, and Pantoea were significantly dominant in the 27 samples. Distance-based redundancy analysis (db-RDA) showed that the content of total flavonoids explained the differences in composition and distribution of endophytic bacterial communities in roots of cultivated medicinal liquorices to the greatest extent. Total soil salt was the most important factor that significantly affected the endophytic bacterial community in soil factors, followed by ammonium nitrogen and nitrate nitrogen. Among the leaf nutrition factors, leaf water content had the most significant effect on the endophytic bacterial community, followed by total phosphorus and total potassium.

CONCLUSIONS: This study not only provides information on the composition and distribution of endophytic bacteria in the roots of medicinal licorices, but also reveals the influence of abiotic factors on the community of endophytic bacteria and bioactive compounds, which provides a reference for improving the quality of licorice.

RevDate: 2021-09-09
CmpDate: 2021-09-09

Di Genio S, Wang LH, Meng PJ, et al (2021)

"Symbio-Cryobank": Toward the Development of a Cryogenic Archive for the Coral Reef Dinoflagellate Symbiont Symbiodiniaceae.

Biopreservation and biobanking, 19(1):91-93.

RevDate: 2021-09-08

Agarwal R, Gupta M, Antony A, et al (2021)

In Vitro Studies Reveal that Pseudomonas, from Odontotermes obesus Colonies, can Function as a Defensive Mutualist as it Prevents the Weedy Fungus While Keeping the Crop Fungus Unaffected.

Microbial ecology [Epub ahead of print].

Insects that farm monocultures of fungi are canonical examples of nutritional symbiosis as well as independent evolution of agriculture in non-human animals. But just like in human agriculture, these fungal crops face constant threat of invasion by weeds which, if unchecked, take over the crop fungus. In fungus-growing termites, the crop fungus (Termitomyces) faces such challenges from the weedy fungus Pseudoxylaria. The mechanism by which Pseudoxylaria is suppressed is not known. However, evidence suggests that some bacterial secondary symbionts can serve as defensive mutualists by preventing the growth of Pseudoxylaria. However, such secondary symbionts must possess the dual, yet contrasting, capabilities of suppressing the weedy fungus while keeping the growth of the crop fungus unaffected. This study describes the isolation, identification, and culture-dependent estimation of the roles of several such putative defensive mutualists from the colonies of the wide-spread fungus-growing termite from India, Odontotermes obesus. From the 38 bacterial cultures tested, a strain of Pseudomonas showed significantly greater suppression of the weedy fungus than the crop fungus. Moreover, a 16S rRNA pan-microbiome survey, using the Nanopore platform, revealed Pseudomonas to be a part of the core microbiota of O. obesus. A meta-analysis of microbiota composition across different species of Odontotermes also confirms the widespread prevalence of Pseudomonas within this termite. These lines of evidence indicate that Pseudomonas could be playing the role of defensive mutualist within Odontotermes.

RevDate: 2021-09-08

Xie J, Yan QL, T Zhang (2020)

[Temporal effects of thinning on the composition and growth of regenerated woody plants in Larix kaempferi plantations].

Ying yong sheng tai xue bao = The journal of applied ecology, 31(8):2481-2490.

Understanding the temporal effects of thinning on the composition and growth of regene-rated broadleaved woody species in coniferous plantations can provide profound references for promoting the conversion of monoculture plantations into mixed conifer-broadleaved forests, which could solve the problem that the production and ecological functions of monoculture plantations cannot be balanced. We compared the composition of regenerated woody plant species in Larix kaempferi plantation with short-term (1-3 years), medium-term (4-9 years) and long-term (>9 years) after thinning. Furthermore, we selected three regenerated tree species with higher importance value and reciprocal symbiosis with L. kaempferi, which differed in shade tolerance, including shade-intolerant species Quercus mongolica, intermediate shade-tolerant species Acer mono, and shade-tolerant species Tilia mandschurica. We analyzed the relationships between light conditions (i.e., canopy density) and the growth (i.e., base diameter and height) of those species in L. kaempferi plantation with different terms after thinning. The results showed that 46 species of regene-rated broadleaved woody plants were recorded in thinned plantations. The common and dominant tree in different terms after thinning was A. mono, and the shrub species were Lonicera japonica and Euonymus alatus. With the increasing time after thinning, species richness of regenerated trees decreased, but the ratio of tree to shrub species increased and the intermediate shade-tolerant tree species took the dominant position. The temporal effect of thinning on the growth of three tree species was affected by shade tolerance ability. Basal diameter and height of T. mandschurica were higher than those of Q. mongolica and A. mono. With the increases of time after thinning, basal diameter of T. mandschurica and height of A. mono were more sensitive to light, indicating that there were respectively "a shade tolerance strategy" and "a shade avoidance strategy" to adapt to the post-thinning environment. The effects of thinning on the composition and growth of regenerated broadleaved woody species in L. kaempferi plantations were significantly time-sensitive. When deve-loping thinning measures to promote the regeneration of broadleaved trees in plantations, we should consider to extend the thinning interval appropriately to ensure the growth of broadleaved tree seedlings (e.g., T. mandschurica and A. mono) and accelerate their migration into the canopy layer. This would promote the formation of mixed conifer-broadleaved forests and eventually realize the sustainable development of plantations.

RevDate: 2021-09-08

Hom EFY, AS Penn (2021)

Symbiosis and the Anthropocene.

Symbiosis (Philadelphia, Pa.) pii:794 [Epub ahead of print].

Recent human activity has profoundly transformed Earth biomes on a scale and at rates that are unprecedented. Given the central role of symbioses in ecosystem processes, functions, and services throughout the Earth biosphere, the impacts of human-driven change on symbioses are critical to understand. Symbioses are not merely collections of organisms, but co-evolved partners that arise from the synergistic combination and action of different genetic programs. They function with varying degrees of permanence and selection as emergent units with substantial potential for combinatorial and evolutionary innovation in both structure and function. Following an articulation of operational definitions of symbiosis and related concepts and characteristics of the Anthropocene, we outline a basic typology of anthropogenic change (AC) and a conceptual framework for how AC might mechanistically impact symbioses with select case examples to highlight our perspective. We discuss surprising connections between symbiosis and the Anthropocene, suggesting ways in which new symbioses could arise due to AC, how symbioses could be agents of ecosystem change, and how symbioses, broadly defined, of humans and "farmed" organisms may have launched the Anthropocene. We conclude with reflections on the robustness of symbioses to AC and our perspective on the importance of symbioses as ecosystem keystones and the need to tackle anthropogenic challenges as wise and humble stewards embedded within the system.

RevDate: 2021-09-08
CmpDate: 2021-09-08

Gichuhi J, Khamis F, Van den Berg J, et al (2020)

Influence of inoculated gut bacteria on the development of Bactrocera dorsalis and on its susceptibility to the entomopathogenic fungus, Metarhizium anisopliae.

BMC microbiology, 20(1):321.

BACKGROUND: Symbiotic interactions between insects and bacteria have been associated with a vast variety of physiological, ecological and evolutionary consequences for the host. A wide range of bacterial communities have been found in association with the oriental fruit fly, Bactrocera dorsalis (Hendel) (Diptera: Tephritidae), an important pest of cultivated fruit in most regions of the world. We evaluated the diversity of gut bacteria in B. dorsalis specimens from several populations in Kenya and investigated the roles of individual bacterial isolates in the development of axenic (germ-free) B. dorsalis fly lines and their responses to the entomopathogenic fungus, Metarhizium anisopliae.

RESULTS: We sequenced 16S rRNA to evaluate microbiomes and coupled this with bacterial culturing. Bacterial isolates were mono-associated with axenic B. dorsalis embryos. The shortest embryonic development period was recorded in flies with an intact gut microbiome while the longest period was recorded in axenic fly lines. Similarly, larval development was shortest in flies with an intact gut microbiome, in addition to flies inoculated with Providencia alcalifaciens. Adult B. dorsalis flies emerging from embryos that had been mono-associated with a strain of Lactococcus lactis had decreased survival when challenged with a standard dosage of M. anisopliae ICIPE69 conidia. However, there were no differences in survival between the germ-free lines and flies with an intact microbiome.

CONCLUSIONS: These findings will contribute to the selection of probiotics used in artificial diets for B. dorsalis rearing and the development of improved integrated pest management strategies based on entomopathogenic fungi.

RevDate: 2021-09-08
CmpDate: 2021-09-08

Sun S, Li F, Xu X, et al (2020)

Study on the community structure and function of symbiotic bacteria from different growth and developmental stages of Hypsizygus marmoreus.

BMC microbiology, 20(1):311.

BACKGROUND: The symbiotic bacteria associated with edible fungi are valuable microbial resources worthy of in-depth exploration. It is important to analyze the community structure and succession of symbiotic bacteria in mushrooms. This can assist in the isolation of growth-promoting strains that have an essential relationship with the cultivation cycle as well as the agronomic traits and yields of fruiting bodies.

RESULTS: In all of the samples from cultivation bags of Hypsizygus marmoreus, 34 bacterial phyla were detected. Firmicutes was the most abundant bacterial phylum (78.85%). The genus Serratia showed an exponential increase in abundance in samples collected from the cultivation bags in the mature period, reaching a peak abundance of 55.74% and the dominant symbiotic flora. The most predominant strain was Serratia odorifera HZSO-1, and its abundance increased with the amount of hyphae of H. marmoreus. Serratia odorifera HZSO-1 could reside in the hyphae of H. marmoreus, promote growth and development, shorten the fruiting cycle by 3-4 days, and further increase the fruiting body yield by 12%.

CONCLUSIONS: This study is a pioneering demonstration of the community structure of the symbiotic microbiota and bacteria-mushroom interaction in the growth and development of edible fungi. This work lays a theoretical foundation to improve the industrial production of mushrooms with symbiotic bacteria as assisting agents.

RevDate: 2021-09-07

Shinkura R (2021)

Therapeutic immunoglobulin A antibody for dysbiosis-related diseases.

International immunology pii:6366027 [Epub ahead of print].

Dysbiosis is alterations in the microbial composition compared with a healthy microbiota and often features a reduction in gut microbial diversity and a change in microbial taxa. Dysbiosis, especially in the gut, has also been proposed to play a crucial role in the pathogenesis of a wide variety of diseases, including inflammatory bowel disease, colorectal cancer, cardiovascular disease, obesity, diabetes and multiple sclerosis. A body of evidence has shown that intestinal polymeric immunoglobulin A (IgA) antibodies are important to regulate the gut microbiota as well as to exclude pathogenic bacteria or viral infection such as influenza and SARS-CoV-2 (severe acute respiratory syndrome coronavirus 2) at mucosal sites. Since the 1970s, trials for oral administration of therapeutic IgA or IgG have been performed mainly to treat infectious enteritis caused by pathogenic Escherichia coli or Clostridium difficile. However, few of them has been successfully developed as a clinical application up to now. In addition to the protective function against intestinal pathogens, IgA is well known to modulate the gut commensal microbiota leading to symbiosis. Nevertheless, the development of therapeutic IgA drugs to treat dysbiosis is not progressing. In this review, the advantages of therapeutic IgA antibodies and the problems for their development will be discussed.

RevDate: 2021-09-07

Muñoz VL, Figueredo MS, Reinoso H, et al (2021)

Role of ethylene in effective establishment of the peanut-bradyrhizobia symbiotic interaction.

Plant biology (Stuttgart, Germany) [Epub ahead of print].

Ethylene has been implicated in nitrogen fixing symbioses in legumes, where rhizobial invasion occurs via infection threads (IT). In the symbiosis between peanut (Arachis hypogaea L.) and bradyrhizobia, the bacteria penetrate the root cortex intercellularly and IT are not formed. Little attention has been paid to the function of ethylene in the establishment of this symbiosis. The aim of this article is to evaluate whether ethylene plays a role in the development of this symbiotic interaction and the participation of Nod Factors (NF) in the regulation of ethylene signalling. Manipulation of ethylene in peanut was accomplished by application of 1-aminocyclopropane-1-carboxylic acid (ACC), which mimics applied ethylene, or AgNO3, which blocks ethylene responses. To elucidate the participation of NF in the regulation of ethylene signalling, we inoculated plants with a mutant isogenic rhizobial strain unable to produce NF and evaluated the effect of AgNO3 on gene expression of NF and ethylene responsive signalling pathways. Data revealed that ethylene perception is required for the formation of nitrogen-fixing nodules, while addition of ACC does not affect peanut symbiotic performance. This phenotypic evidence is in agreement with transcriptomic data from genes involved in symbiotic and ethylene signalling pathways. NF seem to modulate the expression of ethylene signalling genes. Unlike legumes infected through IT formation, ACC addition to peanut does not adversely affect nodulation, but ethylene perception is required for establishment of this symbiosis. Evidence for the contribution of NF to the modulation of ethylene-inducible defence gene expression is provided.

RevDate: 2021-09-07

Sonel E, Gür Ş, T Eren (2021)

Analysis of factors affecting industrial symbiosis collaboration.

Environmental science and pollution research international [Epub ahead of print].

The rapidly increasing population causes an increase in consumption amounts day by day. This leads to negative effects such as the reduction of limited resources. In order to eliminate or reduce such negative effects, sustainable approaches are adopted for the future. Industrial symbiosis is one of these sustainable approaches. Industrial symbiosis is when two or more economic enterprises operating independently of each other form beneficial partnerships. In this study, the factors affecting industrial symbiosis collaboration were determined by literature review and by analyzing these factors; it is aimed to eliminate inefficiencies and to ensure the sustainability of established relations. The criteria determined are weighted with the Analytical Network Process method, which is one of the multi-criteria decision-making methods, and it is aimed to calculate the degree of importance and priority.

RevDate: 2021-09-07

Bitomský M, Pakeman RJ, Schaefer H, et al (2021)

Mycorrhizal status is a poor predictor of the distribution of herbaceous species along the gradient of soil nutrient availability in coastal and grassland habitats.

Mycorrhiza [Epub ahead of print].

Plant mycorrhizal status (a trait indicating the ability to form mycorrhizas) can be a useful plant trait for predicting changes in vegetation influenced by increased fertility. Mycorrhizal fungi enhance nutrient uptake and are expected to provide a competitive advantage for plants growing in nutrient-poor soils; while in nutrient-rich soils, mycorrhizal symbiosis may be disadvantageous. Some studies in natural systems have shown that mycorrhizal plants can be more frequent in P and N-poor soils (low nutrient availability) or Ca and Mg-high (high pH) soils, but empirical support is still not clear. Using vegetation and soil data from Scottish coastal habitats, and Latvian and Czech grasslands, we examined whether there is a link between plant mycorrhizal status and plant-available P, N, Ca and Mg. We performed the max test analysis (to examine the central tendency) and a combination of quantile regression and meta-analysis (to examine tendencies in different quantiles) on both community and plant species data combined with plant phylogenies. We consistently found no changes in mycorrhizal status at the community and species levels along the gradients of plant-available P, N, Ca and Mg in the central tendency and in almost all quantiles across all datasets. Thus, we found no support for the hypotheses that herbaceous species which are able to form mycorrhizas are more frequent in nutrient-poor and high pH environments. Obligatory, facultatively and non-mycorrhizal herbaceous species appear to assemble randomly along the gradients of nutrient availability in several European herbaceous habitats, suggesting that all these strategies perform similarly under non-extreme soil nutrient conditions.

RevDate: 2021-09-07

Tang N, Lebreton A, Xu W, et al (2021)

Transcriptome Profiling Reveals Differential Gene Expression of Secreted Proteases and Highly Specific Gene Repertoires Involved in Lactarius-Pinus Symbioses.

Frontiers in plant science, 12:714393.

Ectomycorrhizal fungi establish a mutualistic symbiosis in roots of most woody plants. The molecular underpinning of ectomycorrhizal development was only explored in a few lineages. Here, we characterized the symbiotic transcriptomes of several milkcap species (Lactarius, Russulales) in association with different pine hosts. A time-course study of changes in gene expression during the development of L. deliciosus-Pinus taeda symbiosis identified 6 to 594 differentially expressed fungal genes at various developmental stages. Up- or down-regulated genes are involved in signaling pathways, nutrient transport, cell wall modifications, and plant defenses. A high number of genes coding for secreted proteases, especially sedolisins, were induced during root colonization. In contrast, only a few genes encoding mycorrhiza-induced small secreted proteins were identified. This feature was confirmed in several other Lactarius species in association with various pines. Further comparison among all these species revealed that each Lactarius species encodes a highly specific symbiotic gene repertoire, a feature possibly related to their host-specificity. This study provides insights on the genetic basis of symbiosis in an ectomycorrhizal order, the Russulales, which was not investigated so far.

RevDate: 2021-09-07

Mendoza-Suárez M, Andersen SU, Poole PS, et al (2021)

Competition, Nodule Occupancy, and Persistence of Inoculant Strains: Key Factors in the Rhizobium-Legume Symbioses.

Frontiers in plant science, 12:690567.

Biological nitrogen fixation by Rhizobium-legume symbioses represents an environmentally friendly and inexpensive alternative to the use of chemical nitrogen fertilizers in legume crops. Rhizobial inoculants, applied frequently as biofertilizers, play an important role in sustainable agriculture. However, inoculants often fail to compete for nodule occupancy against native rhizobia with inferior nitrogen-fixing abilities, resulting in low yields. Strains with excellent performance under controlled conditions are typically selected as inoculants, but the rates of nodule occupancy compared to native strains are rarely investigated. Lack of persistence in the field after agricultural cycles, usually due to the transfer of symbiotic genes from the inoculant strain to naturalized populations, also limits the suitability of commercial inoculants. When rhizobial inoculants are based on native strains with a high nitrogen fixation ability, they often have superior performance in the field due to their genetic adaptations to the local environment. Therefore, knowledge from laboratory studies assessing competition and understanding how diverse strains of rhizobia behave, together with assays done under field conditions, may allow us to exploit the effectiveness of native populations selected as elite strains and to breed specific host cultivar-rhizobial strain combinations. Here, we review current knowledge at the molecular level on competition for nodulation and the advances in molecular tools for assessing competitiveness. We then describe ongoing approaches for inoculant development based on native strains and emphasize future perspectives and applications using a multidisciplinary approach to ensure optimal performance of both symbiotic partners.

RevDate: 2021-09-07

Prazeres M, Roberts TE, Ramadhani SF, et al (2021)

Diversity and flexibility of algal symbiont community in globally distributed larger benthic foraminifera of the genus Amphistegina.

BMC microbiology, 21(1):243.

BACKGROUND: Understanding the specificity and flexibility of the algal symbiosis-host association is fundamental for predicting how species occupy a diverse range of habitats. Here we assessed the algal symbiosis diversity of three species of larger benthic foraminifera from the genus Amphistegina and investigated the role of habitat and species identity in shaping the associated algal community.

RESULTS: We used next-generation sequencing to identify the associated algal community, and DNA barcoding to identify the diatom endosymbionts associated with species of A. lobifera, A. lessonii, and A. radiata, collected from shallow habitats (< 15 m) in 16 sites, ranging from the Mediterranean Sea to French Polynesia. Next-generation sequencing results showed the consistent presence of Ochrophyta as the main algal phylum associated with all species and sites analysed. A significant proportion of phylotypes were classified as Chlorophyta and Myzozoa. We uncovered unprecedented diversity of algal phylotypes found in low abundance, especially of the class Bacillariophyta (i.e., diatoms). We found a significant influence of sites rather than host identity in shaping algal communities in all species. DNA barcoding revealed the consistent presence of phylotypes classified within the order Fragilariales as the diatoms associated with A. lobifera and A. lessonii, while A. radiata specimens host predominately diatoms of the order Triceratiales.

CONCLUSIONS: We show that local habitat is the main factor influencing the overall composition of the algal symbiont community. However, host identity and the phylogenetic relationship among hosts is relevant in shaping the specific endosymbiont diatom community, suggesting that the relationship between diatom endosymbiont and hosts plays a crucial role in the evolutionary history of the genus Amphistegina. The capacity of Amphistegina species to associate with a diverse array of diatoms, and possibly other algal groups, likely underpins the ecological success of these crucial calcifying organisms across their extensive geographic range.

RevDate: 2021-09-07

Chrostek E, Martins N, Marialva MS, et al (2021)

Wolbachia-Conferred Antiviral Protection Is Determined by Developmental Temperature.

mBio [Epub ahead of print].

Wolbachia is a maternally transmitted bacterium that is widespread in arthropods and filarial nematodes and confers strong antiviral protection in Drosophila melanogaster and other arthropods. Wolbachia-transinfected Aedes aegypti mosquitoes are currently being deployed to fight transmission of dengue and Zika viruses. However, the mechanism of antiviral protection and the factors influencing are still not fully understood. Here, we show that temperature modulates Wolbachia-conferred protection in Drosophila melanogaster. Temperature after infection directly impacts Drosophila C virus (DCV) replication and modulates Wolbachia protection. At higher temperatures, viruses proliferate more and are more lethal, while Wolbachia confers lower protection. Strikingly, host developmental temperature is a determinant of Wolbachia-conferred antiviral protection. While there is strong protection when flies develop from egg to adult at 25°C, the protection is highly reduced or abolished when flies develop at 18°C. However, Wolbachia-induced changes during development are not sufficient to limit virus-induced mortality, as Wolbachia is still required to be present in adults at the time of infection. This developmental effect is general, since it was present in different host genotypes, Wolbachia variants, and upon infection with different viruses. Overall, we show that Wolbachia-conferred antiviral protection is temperature dependent, being present or absent depending on the environmental conditions. This interaction likely impacts Wolbachia-host interactions in nature and, as a result, frequencies of host and symbionts in different climates. Dependence of Wolbachia-mediated pathogen blocking on developmental temperature could be used to dissect the mechanistic bases of protection and influence the deployment of Wolbachia to prevent transmission of arboviruses. IMPORTANCE Insects are often infected with beneficial intracellular bacteria. The bacterium Wolbachia is extremely common in insects and can protect them from pathogenic viruses. This effect is being used to prevent transmission of dengue and Zika viruses by Wolbachia-infected mosquitoes. To understand the biology of insects in the wild, we need to discover which factors affect Wolbachia-conferred antiviral protection. Here, we show that the temperature at which insects develop from eggs to adults can determine the presence or absence of antiviral protection. The environment, therefore, strongly influences this insect-bacterium interaction. Our work may help to provide insights into the mechanism of viral blocking by Wolbachia, deepen our understanding of the geographical distribution of host and symbiont, and incentivize further research on the temperature dependence of Wolbachia-conferred protection for control of mosquito-borne disease.

RevDate: 2021-09-07
CmpDate: 2021-09-07

Bosse MA, Silva MBD, Oliveira NGRM, et al (2021)

Physiological impact of flavonoids on nodulation and ureide metabolism in legume plants.

Plant physiology and biochemistry : PPB, 166:512-521.

Legume plants from Fabaceae family (phylogenetic group composed by three subfamilies: Caesalpinioideae, Mimosoideae, and Papilionoideae) can fix atmospheric nitrogen (N2) into ammonia (NH3) by the symbiotic relationship with rhizobia bacteria. These bacteria respond chemotactically to certain compounds released by plants such as sugars, amino acids and organic acids. Root secretion of isoflavonoids acts as inducers for nod genes in rhizobia and ABC transporters and ICHG (isoflavone conjugates hydrolyzing beta-glucosidase) at apoplast are related to the exudation of genistein and daidzein in soybean roots. Biological nitrogen fixation (BNF) occurs inside the nodule by the action of nitrogenase enzyme, which fixes N2 into NH3, which is converted into ureides (allantoin and allantoic acid). In this review, we bring together the latest findings on flavonoids biosynthesis and ureide metabolism in several legume plant species. We emphasize how flavonoids induce nod genes in rhizobia, affecting chemotaxis, nodulation, ureide production, growth and yield of legume plants. Mainly, isoflavonoids daidzein and genistein are responsible for nod genes activation in the rhizobia bacteria. Flavonoids also play an important role during nodule organogenesis by acting as auxin transporter inhibitors in root cells, especially in indeterminate nodules. The ureides are the main N transport form in tropical legumes and they are catabolized in leaves and other sink tissues to produce amino acids and proteins needed for plant growth and yield.

RevDate: 2021-09-07
CmpDate: 2021-09-07

Weis AM, JL Round (2021)

Microbiota-antibody interactions that regulate gut homeostasis.

Cell host & microbe, 29(3):334-346.

Immunoglobulin A (IgA) is the most abundant antibody at mucosal surfaces and has been the subject of many investigations involving microbiota research in the last decade. Although the classic functions of IgA include neutralization of harmful toxins, more recent investigations have highlighted an important role for IgA in regulating the composition and function of the commensal microbiota. Multiple reviews have comprehensively covered the literature that describes recent, novel mechanisms of action of IgA and development of the IgA response within the intestine. Here we focus on how the interaction between IgA and the microbiota promotes homeostasis with the host to prevent disease.

RevDate: 2021-09-07
CmpDate: 2021-09-07

Becattini S, Sorbara MT, Kim SG, et al (2021)

Rapid transcriptional and metabolic adaptation of intestinal microbes to host immune activation.

Cell host & microbe, 29(3):378-393.e5.

The gut microbiota produces metabolites that regulate host immunity, thereby impacting disease resistance and susceptibility. The extent to which commensal bacteria reciprocally respond to immune activation, however, remains largely unexplored. Herein, we colonized mice with four anaerobic symbionts and show that acute immune responses result in dramatic transcriptional reprogramming of these commensals with minimal changes in their relative abundance. Transcriptomic changes include induction of stress-response mediators and downregulation of carbohydrate-degrading factors such as polysaccharide utilization loci (PULs). Flagellin and anti-CD3 antibody, two distinct immune stimuli, induced similar transcriptional profiles, suggesting that commensal bacteria detect common effectors or activate shared pathways when facing different host responses. Immune activation altered the intestinal metabolome within 6 hours, decreasing luminal short-chain fatty acid and increasing aromatic metabolite concentrations. Thus, intestinal bacteria, prior to detectable shifts in community composition, respond to acute host immune activation by rapidly changing gene transcription and immunomodulatory metabolite production.

RevDate: 2021-09-07
CmpDate: 2021-09-07

Gao S, Kong Y, Yu J, et al (2020)

Isolation of axenic cyanobacterium and the promoting effect of associated bacterium on axenic cyanobacterium.

BMC biotechnology, 20(1):61.

BACKGROUND: Harmful cyanobacterial blooms have attracted wide attention all over the world as they cause water quality deterioration and ecosystem health issues. Microcystis aeruginosa associated with a large number of bacteria is one of the most common and widespread bloom-forming cyanobacteria that secret toxins. These associated bacteria are considered to benefit from organic substrates released by the cyanobacterium. In order to avoid the influence of associated heterotrophic bacteria on the target cyanobacteria for physiological and molecular studies, it is urgent to obtain an axenic M. aeruginosa culture and further investigate the specific interaction between the heterotroph and the cyanobacterium.

RESULTS: A traditional and reliable method based on solid-liquid alternate cultivation was carried out to purify the xenic cyanobacterium M. aeruginosa FACHB-905. On the basis of 16S rDNA gene sequences, two associated bacteria named strain B905-1 and strain B905-2, were identified as Pannonibacter sp. and Chryseobacterium sp. with a 99 and 97% similarity value, respectively. The axenic M. aeruginosa FACHB-905A (Microcystis 905A) was not able to form colonies on BG11 agar medium without the addition of strain B905-1, while it grew well in BG11 liquid medium. Although the presence of B905-1 was not indispensable for the growth of Microcystis 905A, B905-1 had a positive effect on promoting the growth of Microcystis 905A.

CONCLUSIONS: The associated bacteria were eliminated by solid-liquid alternate cultivation method and the axenic Microcystis 905A was successfully purified. The associated bacterium B905-1 has the potentiality to promote the growth of Microcystis 905A. Moreover, the purification technique for cyanobacteria described in this study is potentially applicable to a wider range of unicellular cyanobacteria.

RevDate: 2021-09-07
CmpDate: 2021-09-07

Jiménez RR, Alvarado G, Sandoval J, et al (2020)

Habitat disturbance influences the skin microbiome of a rediscovered neotropical-montane frog.

BMC microbiology, 20(1):292.

BACKGROUND: The skin microbiome serves as a first line defense against pathogens in vertebrates. In amphibians, it has the potential to protect against the chytrid fungus Batrachochytrium dendrobatis (Bd), a likely agent of amphibian declines. Alteration of the microbiome associated with unfavorable environmental changes produced by anthropogenic activities may make the host more susceptible to pathogens. Some amphibian species that were thought to be "extinct" have been rediscovered years after population declines in the late 1980s probably due to evolved Bd-resistance and are now threatened by anthropogenic land-use changes. Understanding the effects of habitat disturbance on the host skin microbiome is relevant for understanding the health of these species, along with its susceptibility to pathogens such as Bd. Here, we investigate the influence of habitat alteration on the skin bacterial communities as well as specifically the putative Bd-inhibitory bacterial communities of the montane frog Lithobates vibicarius. This species, after years of not being observed, was rediscovered in small populations inhabiting undisturbed and disturbed landscapes, and with continuous presence of Bd.

RESULTS: We found that cutaneous bacterial communities of tadpoles and adults differed between undisturbed and disturbed habitats. The adults from disturbed habitats exhibited greater community dispersion than those from undisturbed habitats. We observed a higher richness of putative Bd-inhibitory bacterial strains in adults from disturbed habitats than in those from undisturbed habitats, as well as a greater number of these potential protective bacteria with a high relative abundance.

CONCLUSIONS: Our findings support the microbial "Anna Karenina principle", in which disturbance is hypothesized to cause greater microbial dispersion in communities, a so-called dysbiosis, which is a response of animal microbiomes to stress factors that decrease the ability of the host or its microbiome to regulate community composition. On the positive side, the high richness and relative abundance of putative Bd-inhibitory bacteria may indicate the development of a defense mechanism that enhances Bd-protection, attributed to a co-occurrence of more than 30-years of host and pathogen in these disturbed habitats. Our results provide important insight into the influence of human-modified landscapes on the skin microbiome and health implications of Bd-survivor species.

RevDate: 2021-09-06

Yang Z, Du H, Xing X, et al (2021)

A small heat shock protein, GmHSP17.9, from nodule confers symbiotic nitrogen fixation and seed yield in soybean.

Plant biotechnology journal [Epub ahead of print].

Legume-rhizobia symbiosis enables biological nitrogen fixation to improve crop production for sustainable agriculture. Small heat shock proteins (sHSPs) are involved in multiple environmental stresses and plant development processes. However, the role of sHSPs in nodule development in soybean remains largely unknown. In the present study, we identified a nodule-localized sHSP, called GmHSP17.9, in soybean, which was markedly upregulated during nodule development. GmHSP17.9 was specifically expressed in the infected regions of the nodules. GmHSP17.9 overexpression and RNAi in transgenic composite plants and loss of function in CRISPR-Cas9 gene-editing mutant plants in soybean resulted in remarkable alterations in nodule number, nodule fresh weight, nitrogenase activity, contents of poly β-hydroxybutyrate bodies (PHBs), ureide, and total nitrogen content, which caused significant changes in plant growth and seed yield. GmHSP17.9 was also found to act as a chaperone for its interacting partner, GmNOD100, a sucrose synthase in soybean nodules which was also preferentially expressed in the infected zone of nodules, similar to GmHSP17.9. Functional analysis of GmNOD100 in composite transgenic plants revealed that GmNOD100 played an essential role in soybean nodulation. The hsp17.9 lines showed markedly more reduced sucrose synthase activity, lower contents of UDP-glucose and acetyl coenzyme A (acetyl-CoA), and decreased activity of succinic dehydrogenase (SDH) in the tricarboxylic acid (TCA) cycle in nodules due to the missing interaction with GmNOD100. Our findings reveal an important role and an unprecedented molecular mechanism of sHSPs in nodule development and nitrogen fixation in soybean.

RevDate: 2021-09-06

Pashkova TM, Morozova NV, Kuzmin MD, et al (2021)

[Characteristics of the pathogenic potential of Escherichia coli isolated from patients with calculous pyelonephritis].

Urologiia (Moscow, Russia : 1999).

OBJECTIVE: Comparative phenotypic and genetic assessment of the pathogenic potential of E. coli strains isolated from patients with calculous pyelonephritis.

MATERIALS AND METHODS: 78 strains of E. coli isolated from urine of patients with calculous pyelonephritis in the acute phase (n=58) and in the remission phase (n=20). Escherichia were investigated for the presence of virulence genes papA, pap EF, papGII; afa, bma E, iutA, fyuA, feoB, kspMTII, usp multiplex PCR using selected primers. Phenotypically determined the ability to biofilm formation, antilysozyme, antihemoglobin, anticytokine, adhesive and sIgA-protease activity E. coli.

RESULTS: The virulent potential of Escherichia coli at the pheno- and genotype levels was characterized. In strains of E. coli isolated from the urine of patients in the remission phase, the ability to form biofilms was more often and with high values of the trait; and in strains isolated in relapse - adhesive activity, the ability to inactivate pro- and anti-inflammatory cytokines, antihemoglobin activity, and genes encoding aphimbrial adhesin (afa), responsible for the synthesis of siderophore aerobactin (iutA), transporting bivalent iron (feoB).

CONCLUSION: The revealed differences in the pheno- and genotypic profiles between the cultures of Escherichia coli isolated from patients with calculous pyelonephritis in the phases of exacerbation and remission make it possible to differentiate the isolated strain and predict the course of the infectious-inflammatory process.

RevDate: 2021-09-06

Rimal Y, Gochhait S, A Bisht (2021)

Data interpretation and visualization of COVID-19 cases using R programming.

Informatics in medicine unlocked pii:S2352-9148(21)00188-X [Epub ahead of print].

Background: Data analysis and visualization are essential for exploring and communicating medical research findings, especially when working with COVID records.

Results: Data on COVID-19 diagnosed cases and deaths from December 2019 is collected automatically from,, and the Multidisciplinary Digital Publishing Institute (MDPI). We have developed an application for data visualization and analysis of several indicators to follow the SARS-CoV-2 epidemic using Statista, Data Hub, and MDPI data from densely populated countries like the United States, Japan, and India using R programming.

Conclusions: The COVID19-World online web application systematically produces daily updated country-specific data visualization and analysis of the SARS-CoV-2 epidemic worldwide. The application will help with a better understanding of the SARS-CoV-2 epidemic worldwide.

RevDate: 2021-09-06

Gould AL, Fritts-Penniman A, A Gaisiner (2021)

Museum Genomics Illuminate the High Specificity of a Bioluminescent Symbiosis for a Genus of Reef Fish.

Frontiers in ecology and evolution, 9:.

Symbiotic relationships between bioluminescent bacteria and fishes have evolved multiple times across hundreds of fish taxa, but relatively little is known about the specificity of these associations and how stable they are over host generations. This study describes the degree of specificity of a bioluminescent symbiosis between cardinalfishes in the genus Siphamia and luminous bacteria in the Vibrio family. Primarily using museum specimens, we investigated the codivergence of host and symbiont and test for patterns of divergence that correlate with both biogeography and time. Contrary to expectations, we determined that the light organ symbionts of all 14 Siphamia species examined belong to one genetic clade of Photobacterium mandapamensis (Clade II), indicating that the association is highly specific and conserved throughout the host genus. Thus, we did not find evidence of codivergence among hosts and symbionts. We did observe that symbionts hosted by individuals sampled from colder water regions were more divergent, containing more than three times as many single nucleotide polymorphisms than the rest of the symbionts examined. Overall, our findings indicate that the symbiosis between Siphamia fishes and P. mandapamensis Clade II has been highly conserved across host taxa and over a broad geographic range despite the facultative nature of the bacterial symbiont. We also present a new approach to simultaneously recover genetic information from a bacterial symbiont and its vertebrate host from formalin-fixed specimens, enhancing the utility of museum collections.

RevDate: 2021-09-06

Jadhav S, V Nema (2021)

HIV-Associated Neurotoxicity: The Interplay of Host and Viral Proteins.

Mediators of inflammation, 2021:1267041.

HIV-1 can incite activation of chemokine receptors, inflammatory mediators, and glutamate receptor-mediated excitotoxicity. The mechanisms associated with such immune activation can disrupt neuronal and glial functions. HIV-associated neurocognitive disorder (HAND) is being observed since the beginning of the AIDS epidemic due to a change in the functional integrity of cells from the central nervous system (CNS). Even with the presence of antiretroviral therapy, there is a decline in the functioning of the brain especially movement skills, noticeable swings in mood, and routine performance activities. Under the umbrella of HAND, various symptomatic and asymptomatic conditions are categorized and are on a rise despite the use of newer antiretroviral agents. Due to the use of long-lasting antiretroviral agents, this deadly disease is becoming a manageable chronic condition with the occurrence of asymptomatic neurocognitive impairment (ANI), symptomatic mild neurocognitive disorder, or HIV-associated dementia. In-depth research in the pathogenesis of HIV has focused on various mechanisms involved in neuronal dysfunction and associated toxicities ultimately showcasing the involvement of various pathways. Increasing evidence-based studies have emphasized a need to focus and explore the specific pathways in inflammation-associated neurodegenerative disorders. In the current review, we have highlighted the association of various HIV proteins and neuronal cells with their involvement in various pathways responsible for the development of neurotoxicity.

RevDate: 2021-09-06

Gupta MM, DHS Richardson (2021)

Editorial: Anthropogenic impacts on symbiotic systems.

RevDate: 2021-09-05

Bishop C, Jurga E, L Graham (2021)

Patterns of bacterial diversity in embryonic capsules of the spotted salamander Ambystoma maculatum: an expanding view of a symbiosis.

FEMS microbiology ecology pii:6364358 [Epub ahead of print].

The unicellular green alga, Oophila amblystomatis, populates egg capsules of the spotted salamander Ambystoma maculatum. This nutrient-exchange mutualism is widely perceived as a bipartite interaction but the presence and contributing effects of bacteria to this symbiosis are unknown. We used standard cultivation techniques and amplicon sequencing of the V4/V5 region of 16S rRNA gene to identify and compare diversity of bacterial taxa in embryonic capsules to that in the aquatic breeding habitat. Our sampling regime allowed us to investigate diversity among individual capsules of an egg mass and between two ponds and sampling years. Capsules contain much lower diversity of bacteria than pond water and spatial and temporal variation in intracapsular and pond bacterial diversity was observed. Despite this variation, sequences corresponding to species in the orders Burkholderiales and Oligoflexales and were either prevalent, abundant, or both. Isolates most commonly recovered from capsules were closely related to species in the genus Herbaspirillum (Burkholderiaceae); other isolates were pseudomonads, but in all cases are closely related to known vascular plant-associated species. We conclude that, despite observed variation, there are bacterial taxa whose presence is held in common spatially and temporally among capsules and that the symbiosis between O. amblystomatis and A. maculatum may involve these taxa.

RevDate: 2021-09-06
CmpDate: 2021-09-06

Huot L, Bigourdan A, Pagès S, et al (2020)

Partner-specific induction of Spodoptera frugiperda immune genes in response to the entomopathogenic nematobacterial complex Steinernema carpocapsae-Xenorhabdus nematophila.

Developmental and comparative immunology, 108:103676.

The Steinernema carpocapsae-Xenorhabdus nematophila association is a nematobacterial complex used in biological control of insect crop pests. The infection success of this dual pathogen strongly depends on its interactions with the host's immune system. Here, we used the lepidopteran pest Spodoptera frugiperda to analyze the respective impact of each partner in the induction of its immune responses. First, we used previously obtained RNAseq data to construct the immunome of S. frugiperda and analyze its induction. We then selected representative genes to study by RT-qPCR their induction kinetics and specificity after independent injections of each partner. We showed that both X. nematophila and S. carpocapsae participate in the induction of stable immune responses to the complex. While X. nematophila mainly induces genes classically involved in antibacterial responses, S. carpocapsae induces lectins and genes involved in melanization and encapsulation. We discuss putative relationships between these differential inductions and the pathogen immunosuppressive strategies.

RevDate: 2021-09-04

Stahlhut KN, Dowell JA, Temme AA, et al (2021)

Genetic control of arbuscular mycorrhizal colonization by Rhizophagus intraradices in Helianthus annuus (L.).

Mycorrhiza [Epub ahead of print].

Plant symbiosis with arbuscular mycorrhizal (AM) fungi provides many benefits, including increased nutrient uptake, drought tolerance, and belowground pathogen resistance. To develop a better understanding of the genetic architecture of mycorrhizal symbiosis, we conducted a genome-wide association study (GWAS) of this plant-fungal interaction in cultivated sunflower. A diversity panel of cultivated sunflower (Helianthus annuus L.) was phenotyped for root colonization under inoculation with the AM fungus Rhizophagus intraradices. Using a mixed linear model approach with a high-density genetic map, we identified genomic regions that are likely associated with R. intraradices colonization in sunflower. Additionally, we used a set of twelve diverse lines to assess the effect that inoculation with R. intraradices has on dried shoot biomass and macronutrient uptake. Colonization among lines in the mapping panel ranged from 0-70% and was not correlated with mycorrhizal growth response, shoot phosphorus response, or shoot potassium response among the Core 12 lines. Association mapping yielded three single-nucleotide polymorphisms (SNPs) that were significantly associated with R. intraradices colonization. This is the first study to use GWAS to identify genomic regions associated with AM colonization in an Asterid eudicot species. Three genes of interest identified from the regions containing these SNPs are likely related to plant defense.

RevDate: 2021-09-04

Qiu X, Gao T, Yang J, et al (2021)

Water-Soluble Humic Materials Modulating Metabolism and Triggering Stress Defense in Sinorhizobium fredii.

Microbiology spectrum, 9(1):e0029321.

Bacteria have evolved a series of mechanisms to maintain their survival and reproduction in changeable and stressful environments. In-depth understanding of these mechanisms can allow for better developing and utilizing of bacteria with various biological functions. In this study, we found that water-soluble humic materials (WSHM), a well-known environment-friendly plant growth biostimulant, significantly promoted the free-living growth and survival of Sinorhizobium fredii CCBAU45436 in a bell-shaped, dose-dependent manner, along with more-efficient carbon source consumption and relief of medium acidification. By using RNA-Seq analysis, a total of 1,136 genes significantly up-/downregulated by external addition of WSHM were identified under test conditions. These differentially expressed genes (DEGs) were enriched in functional categories related to carbon/nitrogen metabolism, cellular stress response, and genetic information processing. Further protein-protein interaction (PPI) network analysis and reverse genetic engineering indicated that WSHM might reprogram the transcriptome through inhibiting the expression of key hub gene rsh, which encodes a bifunctional enzyme catalyzing synthesis and hydrolysis of the "magic spot" (p)ppGpp. In addition, the root colonization and viability in soil of S. fredii CCBAU45436 were increased by WSHM. These findings provide us with new insights into how WSHM benefit bacterial adaptations and demonstrate great application value to be a unique inoculant additive. IMPORTANCE Sinorhizobium fredii CCBAU45436 is a highly effective, fast-growing rhizobium that can establish symbiosis with multiple soybean cultivars. However, it is difficult to maintain the high-density effective viable cells in the rhizobial inoculant for the stressful conditions during production, storage, transport, and application. Here, we showed that WSHM greatly increased the viable cells of S. fredii CCBAU45436 in culture, modulating metabolism and triggering stress defense. The root colonization and viability in soil of S. fredii CCBAU45436 were also increased by WSHM. Our results shed new insights into the effects of WSHM on bacteria and the importance of metabolism and stress defense during the bacteria's whole life. In addition, the functional mechanism of WSHM may provide candidate genes for improving environmental adaptability and application potential of bacteria through genetic engineering.

RevDate: 2021-09-03

Côté IM, SJ Brandl (2021)

Functional niches of cleanerfish species are mediated by habitat use, cleaning intensity, and client selectivity.

The Journal of animal ecology [Epub ahead of print].

An animal's functional niche is a complex, multidimensional construct, mediated by an individual's morphology, physiology, and behaviour. Behavioural aspects of the niche can be difficult to quantify, as their expression is often subtle and tailored to an infinite number of different situations that involve sophisticated mechanisms such as mutualisms, species dominance, or fear effects. The extreme diversity of tropical fish assemblages has led to extensive debate over the extent to which species differ in their resource use and functional role. Ectoparasite removal by cleanerfish species is considered a behaviourally complex interspecific interaction in vertebrates, but differences in the services rendered by various species of cleanerfish, and potential consequences for the range of clients (i.e., resources) they attract, have rarely been examined. Here, we quantify differences among three coexisting species of morphologically similar cleaner wrasses (Labroides bicolor, L. dimidiatus, and L. pectoralis) in the global centre of marine biodiversity, the Coral Triangle. We found no clear taxonomic partitioning of clients among cleanerfishes. However, the three cleanerfish species exhibited distinct habitat preferences, and differed in their cleaning intensity: L. bicolor serviced the fewest species and clients, while L. pectoralis serviced the most clients and spent the most time cleaning. Accordingly, L. pectoralis showed no preference for clients based on client size or abundance, while both L. bicolor and L. dimidiatus had a higher likelihood of interacting with clients based on their size (larger client species in L. bicolor, smaller client species in L. dimidiatus) and abundance (more abundant client species for both). Our results suggest that the services rendered by the three species of cleanerfishes differ in their spatial availability, quality, and selectivity, thus permitting the coexistence of these species despite their ecological similarity. This, in turn, creates a complex seascape of species-specific cleaning services that underpins crucial biotic interactions in the ocean's most diverse ecosystem.

RevDate: 2021-09-03

Dusselier M, Ke Q, Khalil I, et al (2021)

A Cooperative OSDA Blueprint for Highly Siliceous Faujasite Zeolite Catalysts with Enhanced Acidity Accessibility.

Angewandte Chemie (International ed. in English) [Epub ahead of print].

A cooperative OSDA strategy is demonstrated, leading to novel high-silica FAU zeolites with a large potential for disruptive acid catalysis. In bottom-up synthesis, the symbiosis of choline ion (Ch +) and 15-crown-5 (CE) was evidenced, in a form of full occupation of the sodalite (sod) cages with the trans Ch + conformer, induced by the CE presence. CE itself occupied the supercages along with additional gauche Ch + , but in synthesis without CE, no trans was found. The cooperation, and thus the fraction of trans Ch + , was closely related to the Si/Al ratio, a key measure for FAU stability and acidity. As such, a bottom-up handle for lowering the Al-content of FAU and tuning its acid site distribution is shown. A mechanistic study demonstrated that forming sod cages with trans Ch + is key to the nucleation of high-silica FAU zeolites. The materials showed superior performances to commercial FAU zeolites and those synthesized without cooperation, in the catalytic degradation of polyethylene.

RevDate: 2021-09-03

Bolejko A, Andersson BT, Debess J, et al (2021)

Facilitators for and barriers to radiography research in public healthcare in Nordic countries.

Radiography (London, England : 1995) pii:S1078-8174(21)00115-2 [Epub ahead of print].

INTRODUCTION: It has been suggested that the future of diagnostic imaging relies on engagement in research and evidence-based practice. This implies a role transition from a clinical radiographer to a clinical radiographer-researcher. Clinical radiographers' stimuli for engaging in research in Nordic countries are unknown. This study aimed to address this gap.

METHODS: Cross-sectional data collection via an online questionnaire on facilitators for and barriers to participation in radiography research was carried out among 507 clinical radiographers in public healthcare in the Nordic countries: Denmark, Finland, Norway and Sweden.

RESULTS: Support from colleagues (odds ratio [OR] 2.62) and other professionals (OR 2.74), and self-esteem in research skills (OR ≥ 2.21), were facilitators for radiography research. Lack of knowledge and skills to conduct research (OR 2.48) was revealed to hinder radiographers' participation in research. The absence of a radiography research culture in the workplace explained non-participation in research (OR 1.75).

CONCLUSION: This study revealed significant factors for clinical radiographers' participation in research.

IMPLICATIONS FOR PRACTICE: A strategy for establishing a radiography research culture in healthcare is proposed that is novel for the context. Management support for knowledge development and activity leading to inter-professional research projects across knowledge fields, provision of a radiography research lead and acknowledgement of radiography research among colleagues signify the establishment of the culture. These prerequisites might provide a paradigm change towards not only the symbiosis of a clinical radiographer and an autonomous researcher but also a partner who adds radiography research to evidence-based practice in diagnostic imaging.

RevDate: 2021-09-03
CmpDate: 2021-09-03

Mao Q, Wu W, Huang L, et al (2020)

Insect Bacterial Symbiont-Mediated Vitellogenin Uptake into Oocytes To Support Egg Development.

mBio, 11(6):.

Many insect species, such as aphids, leafhoppers, planthoppers, and whiteflies harbor obligate bacterial symbionts that can be transovarially transmitted to offspring through the oocytes of female insects. Whether obligate bacterial symbionts can carry important molecules/resources to the embryos to support egg development is still unknown. Here, we show that the vitellogenin (Vg) precursor of rice leafhopper Nephotettix cincticeps is biosynthesized by the fat body, secreted into the hemolymph and subsequently cleaved into the 35- and 178-kDa subunits, whereas only the 178-kDa subunit is taken up by the leading end of oocytes in a receptor-dependent manner or moves into the posterior pole of the terminal oocyte in association with obligate bacterial symbiont "Candidatus Nasuia deltocephalinicola" (hereafter Nasuia) in a receptor-independent manner. Furthermore, the 178-kDa Vg subunit can directly interact with a surface channel molecule (porin) on the envelope of Nasuia, allowing Vg to enter bacterial cytoplasm. Thus, Vg can hitchhike the ancient oocyte entry path of Nasuia, the common obligate symbiont of leafhoppers. Knocking down a Nasuia growth-related protein expression or treatment with porin antibody strongly prevents the ability of Nasuia to carry Vgs into oocytes and impair insect egg development. Nasuia-carried Vgs provide at least 20% of the total Vgs in the developing eggs. We anticipate that the bacterial symbiont-mediated Vg uptake into oocytes to support efficient egg development may be a common pattern shared by many insects.IMPORTANCE Many insects harbor obligate bacterial symbionts that can be vertically transmitted to offspring by female insects through eggs. Here, we report that leafhopper vitellogenin (Vg) recognizes and binds a surface channel molecule (porin) on the envelope of obligate bacterial symbiont Nasuia, which potentially induces the opening of porin channels for Vg to access the cytoplasm of Nasuia Thus, Vg can exploit bacterial symbionts as the independent carriers into the oocytes. Such Nasuia-carried Vg contents support efficient insect egg development. Thus, our findings indicate that insects have evolved strategies to exploit the symbionts for carrying additional Vgs to guarantee optimal insect reproduction.

RevDate: 2021-09-02

Bizarria Júnior R, Pagnocca FC, A Rodrigues (2021)

Yeasts in the attine ant-fungus mutualism: diversity, functional roles, and putative biotechnological applications.

Yeast (Chichester, England) [Epub ahead of print].

Insects interact with a wide variety of yeasts, often providing a suitable substrate for their growth. Some yeast-insect interactions are tractable models for understanding the relationships between the symbionts. Attine ants are prominent insects on the Neotropics and have performed an ancient fungiculture of mutualistic basidiomycete fungi for more than 55-65 million years. Yeasts gain access to this sophisticated mutualism, prompting diversity, ecological, and biotechnological studies in this environment. We reviewed half a century research in this field, surveying for recurrent yeast taxa and their putative ecological roles in this environment. We found that previous studies mainly covered the yeast diversity from a small fraction of attine ants, being Saccharomycetales, Tremellales, and Trichosporonales as the most frequent yeast or yeast-like orders. Apiotrichum, Aureobasidium, Candida, Cutaneotrichosporon, Debaryomyces, Meyerozyma, Papiliotrema, Rhodotorula, Trichomonascus, and Trichosporon are the most frequent recovered genera. On the other hand, yeast's ecological role on attine ant-fungus mutualism only tapped the tip of the iceberg. Previous established hypotheses in the literature cover the production of lignocellulosic enzymes, chemical detoxification, and fungus garden protection. Some of these roles have parallels in biotechnological processes. In conclusion, the attine ant environment has a hidden potential for studying yeast biodiversity, ecology, and biotechnology, which has been particularly unexplored considering the vast diversity of fungus-growing ants.

RevDate: 2021-09-02

Dauphin B, de Freitas Pereira M, Kohler A, et al (2021)

Cryptic genetic structure and copy-number variation in the ubiquitous forest symbiotic fungus Cenococcum geophilum.

Environmental microbiology [Epub ahead of print].

Ectomycorrhizal (ECM) fungi associated with plants constitute one of the most successful symbiotic interactions in forest ecosystems. ECM support trophic exchanges with host plants and are important factors for the survival and stress resilience of trees. However, ECM clades often harbour morpho-species and cryptic lineages, with weak morphological differentiation. How this relates to intraspecific genome variability and ecological functioning is poorly known. Here, we analysed 16 European isolates of the ascomycete Cenococcum geophilum, an extremely ubiquitous forest symbiotic fungus with no known sexual or asexual spore forming structures but with a massively enlarged genome. We carried out whole-genome sequencing to identify single-nucleotide polymorphisms. We found no geographic structure at the European scale but divergent lineages within sampling sites. Evidence for recombination was restricted to specific cryptic lineages. Lineage differentiation was supported by extensive copy-number variation. Finally, we confirmed heterothallism with a single MAT1 idiomorph per genome. Synteny analyses of the MAT1 locus revealed substantial rearrangements and a pseudogene of the opposite MAT1 idiomorph. Our study provides the first evidence for substantial genome-wide structural variation, lineage-specific recombination and low continent-wide genetic differentiation in C. geophilum. Our study provides a foundation for targeted analyses of intra-specific functional variation in this major symbiosis. This article is protected by copyright. All rights reserved.

RevDate: 2021-09-02

Fukudome M, Shimokawa Y, Hashimoto S, et al (2021)

Nitric Oxide Detoxification by Mesorhizobium loti Affects Root Nodule Symbiosis with Lotus japonicus.

Microbes and environments, 36(3):.

Root nodule symbiosis between legumes and rhizobia involves nitric oxide (NO) regulation by both the host plant and symbiotic rhizobia. However, the mechanisms by which the rhizobial control of NO affects root nodule symbiosis in Lotus japonicus are unknown. Therefore, we herein investigated the effects of enhanced NO removal by Mesorhizobium loti on symbiosis with L. japonicus. The hmp gene, which in Sinorhizobium meliloti encodes a flavohemoglobin involved in NO detoxification, was introduced into M. loti to generate a transconjugant with enhanced NO removal. The symbiotic phenotype of the transconjugant with L. japonicus was examined. The transconjugant showed delayed infection and higher nitrogenase activity in mature nodules than the wild type, whereas nodule senescence was normal. This result is in contrast to previous findings showing that enhanced NO removal in L. japonicus by class 1 phytoglobin affected nodule senescence. To evaluate differences in NO detoxification between M. loti and L. japonicus, NO localization in nodules was investigated. The enhanced expression of class 1 phytoglobin in L. japonicus reduced the amount of NO not only in infected cells, but also in vascular bundles, whereas that of hmp in M. loti reduced the amount of NO in infected cells only. This difference suggests that NO detoxification by M. loti exerts different effects in symbiosis than that by L. japonicus.

RevDate: 2021-09-02
CmpDate: 2021-09-02

Cusumano A, AN Volkoff (2021)

Influence of parasitoid-associated viral symbionts on plant-insect interactions and biological control.

Current opinion in insect science, 44:64-71.

Insect parasitoids have evolved symbiotic interactions with several viruses and thousands of parasitoid species have established mutualistic associations with polydnaviruses (PDVs). While PDVs have often been described as virulence factors allowing development of immature parasitoids inside their herbivore hosts, there is increasing awareness that PDVs can affect plant-insect interactions. We review recent literature showing that PDVs alter not only host physiology, but also feeding patterns and composition of herbivore's oral secretions. In turn PDV-induced changes in herbivore phenotype affect plant responses to herbivory with consequences ranging from differential expression of plant defense-related genes to wider ecological effects across multiple trophic levels. In this opinion paper we also highlight important missing gaps to fully understand the role of PDVs and other parasitoid-associated viral symbionts in a plant-insect interaction perspective. Because PDVs negatively impact performance and survival of herbivore pests, we conclude arguing that PDV genomes offer potential opportunities for biological control.

RevDate: 2021-09-02
CmpDate: 2021-09-02

Moon EK, Park SM, Chu KB, et al (2021)

Differentially Expressed Gene Profile of Acanthamoeba castellanii Induced by an Endosymbiont Legionella pneumophila.

The Korean journal of parasitology, 59(1):67-75.

Legionella pneumophila is an opportunistic pathogen that survives and proliferates within protists such as Acanthamoeba spp. in environment. However, intracellular pathogenic endosymbiosis and its implications within Acanthamoeba spp. remain poorly understood. In this study, RNA sequencing analysis was used to investigate transcriptional changes in A. castellanii in response to L. pneumophila infection. Based on RNA sequencing data, we identified 1,211 upregulated genes and 1,131 downregulated genes in A. castellanii infected with L. pneumophila for 12 hr. After 24 hr, 1,321 upregulated genes and 1,379 downregulated genes were identified. Gene ontology (GO) analysis revealed that L. pneumophila endosymbiosis enhanced hydrolase activity, catalytic activity, and DNA binding while reducing oxidoreductase activity in the molecular function (MF) domain. In particular, multiple genes associated with the GO term 'integral component of membrane' were downregulated during endosymbiosis. The endosymbiont also induced differential expression of various methyltransferases and acetyltransferases in A. castellanii. Findings herein are may significantly contribute to understanding endosymbiosis of L. pneumophila within A. castellanii.

RevDate: 2021-09-02
CmpDate: 2021-09-02

de Paula GT, Menezes C, Pupo MT, et al (2021)

Stingless bees and microbial interactions.

Current opinion in insect science, 44:41-47.

Stingless bees (Meliponini) are a monophyletic group of eusocial insects inhabiting tropical and subtropical regions. These insects represent the most abundant and diversified group of corbiculate bees. Meliponini mostly rely on fermentation by symbiont microbes to preserve honey and transform pollen in stored food. Bee nests harbor diverse microbiota that includes bacteria, yeasts, filamentous fungi, and viruses. These microorganisms may interact with the bees through symbiotic relationships, or they may act as food for the insects, or produce biomolecules that aid in the biotransformation of bee products, such as honey and bee bread. Certain microbial species can also produce antimicrobial compounds that inhibit opportunistic bee pathogens.

RevDate: 2021-09-02
CmpDate: 2021-09-02

Gavrin A, Rey T, Torode TA, et al (2020)

Developmental Modulation of Root Cell Wall Architecture Confers Resistance to an Oomycete Pathogen.

Current biology : CB, 30(21):4165-4176.e5.

The cell wall is the primary interface between plant cells and their immediate environment and must balance multiple functionalities, including the regulation of growth, the entry of beneficial microbes, and protection against pathogens. Here, we demonstrate how API, a SCAR2 protein component of the SCAR/WAVE complex, controls the root cell wall architecture important for pathogenic oomycete and symbiotic bacterial interactions in legumes. A mutation in API results in root resistance to the pathogen Phytophthora palmivora and colonization defects by symbiotic rhizobia. Although api mutant plants do not exhibit significant overall growth and development defects, their root cells display delayed actin and endomembrane trafficking dynamics and selectively secrete less of the cell wall polysaccharide xyloglucan. Changes associated with a loss of API establish a cell wall architecture with altered biochemical properties that hinder P. palmivora infection progress. Thus, developmental stage-dependent modifications of the cell wall, driven by SCAR/WAVE, are important in balancing cell wall developmental functions and microbial invasion.

RevDate: 2021-09-01

Wang P, Snijders R, Kohlen W, et al (2021)

Medicago SPX1 and SPX3 regulate phosphate homeostasis, mycorrhizal colonization, and arbuscule degradation.

The Plant cell pii:6361634 [Epub ahead of print].

To acquire sufficient mineral nutrients such as phosphate (Pi) from the soil, most plants engage in symbiosis with arbuscular mycorrhizal (AM) fungi. Attracted by plant-secreted strigolactones, the fungi colonize the roots and form highly-branched hyphal structures called arbuscules inside inner cortex cells. The host plant must control the different steps of this interaction to maintain its symbiotic nature. However, how plants sense the amount of Pi obtained from the fungus, and how this determines the arbuscule lifespan, are far from understood. Here, we show that Medicago truncatula SPX-domain containing proteins SPX1 and SPX3 regulate root Pi starvation responses, in part by interacting with PHOSPHATE RESPONSE REGULATOR2, as well as fungal colonization and arbuscule degradation. SPX1 and SPX3 are induced upon Pi starvation but become more restricted to arbuscule-containing cells upon the establishment of symbiosis. This induction in arbuscule-containing cells is associated with the presence of cis-regulatory AW-boxes and transcriptional regulation by the WRINKLED1-like transcription factor WRI5a. Under Pi-limiting conditions, SPX1 and SPX3 facilitate the expression of the strigolactone biosynthesis gene DWARF27, which could help explain the increased fungal branching in response to root exudates. Later, in arbuscule-containing cells, SPX1 and SPX3 redundantly control arbuscule degradation. Thus, SPX proteins play important roles as phosphate sensors to maintain a beneficial AM symbiosis.

RevDate: 2021-09-01

Sheng H, Weng R, He Y, et al (2021)

The coupling of mixotrophic denitrification, dissimilatory nitrate reduction to ammonium (DNRA) and anaerobic ammonium oxidation (anammox) promoting the start-up of anammox by addition of calcium nitrate.

Bioresource technology, 341:125822 pii:S0960-8524(21)01163-9 [Epub ahead of print].

This study discovered one nitrate-calcium-based anammox start-up pathway. Compared with control, the start-up time of anammox was saved by 33.3%, and the average total nitrogen removal efficiency increased from 29.6% to 53.7% during the start-up. Besides, the continuous nitrite accumulation (1.18 mg/L) and a marked increase in the relative abundance of denitrifying and anammox bacteria were observed in the only Ca(NO3)2-added group. These results suggested that calcium nitrate induced partial denitrification to provide nitrite for anammox. Additionally, the role of dissimilatory nitrate reduction to ammonium (DNRA) in the Ca(NO3)2-added systems also deserved attention, for the contribution of DNRA to nitrate removal as well as the relative abundance of DNRA bacteria were both increased for the Ca(NO3)2-added groups. These results suggested that a mutualistic symbiosis among denitrification, DNRA and anammox exists in the calcium nitrate-added systems, which may explain the reason for acceleration of anammox start-up by adding calcium nitrate.

RevDate: 2021-09-01

Fuentes Barrera GA, Gabarrell I Durany X, Rieradevall Pons J, et al (2021)

Trends in global research on industrial parks: A bibliometric analysis from 1996-2019.

Heliyon, 7(8):e07778 pii:S2405-8440(21)01881-8.

Industrial parks have been used to promote the economic development of countries. However, its rapid growth has generated environmental problems related to the depletion of natural resources and pollution. Consequently, the network analysis and the bibliometric analysis applied in this research generated qualitative and quantitative information from a systemic perspective on the thematic and community evolution of research on industrial parks (IP) performed to improve its negative environmental impact and reach sustainability. This study used the Web of Science (WoS) database from 1996 - 2019. The main trends and critical research points were identified in four periods of 6-year each. Social network analysis (SNA) was used to identify the intellectual structure main and the academic collaboration networks established among countries/territories, institutions, and authors. The most productive country in articles is currently China (882), however, when we consider the frequency of articles per million inhabitants, it ranks seventh. The WoS database grouped 63.6 ​% of the articles published in the subjects of "Environmental Sciences & Ecology", "Engineering", and "Science & Technology - Other Topics". Industrial Ecology (IE), Industrial Symbiosis (IS), and Circular Economy (CE) were the author keywords with the highest frequency, indicating that IP research has focused from these perspectives to promote the exchange of byproducts and to evaluate the performance and environmental impact of industrial areas through the use of methodologies such as carbon footprints, emergy analysis, and life cycle analysis (LCA). Finally, some themes were identified and proposed for future research based on analyzing research trends and hot spots from the literature review on industrial parks.

RevDate: 2021-09-01

Wei X, Chen J, Zhang C, et al (2020)

Ericoid mycorrhizal fungus enhances microcutting rooting of Rhododendron fortunei and subsequent growth.

Horticulture research, 7(1):140.

Adventitious root (AR) formation is a unique feature of plant reproduction and plays a vital role in crop production as many horticultural and forestry plants are propagated through cuttings. A growing number of reports have shown that microbes, particularly mycorrhizal fungi are able to promote AR formation, but the underlying mechanisms remain largely unclear. This study established an in vitro culture system and investigated AR formation in microcuttings of Rhododendron fortunei Lindl. inoculated with Oidiodendron maius Barron Om19, an ericoid mycorrhizal fungus strain. Hormones and precursors involved in the biosynthesis of indole-3-acetic acid (IAA) in Om19 mycelium were analyzed. Om19 was able to produce a large quantity of tryptophan (Trp) and also indole-3-pyruvate (IPA) and IAA, indicating that IAA biosynthesis in Om19 could be through a Trp-dependent pathway. After inoculation of Om19, ARs were quickly formed in microcuttings. Symbiosis related genes were activated in ARs, and Om19 effectively colonized the roots. YUC3, a key gene in plant biosynthesis of IAA and genes involved in nitrogen (N) uptake and metabolism, phosphorus (P) uptake were highly upregulated. Plants absorbed significantly greater quantity of mineral nutrients, and their growth was substantially enhanced compared to the control plants without Om19 inoculation. A working model for Om19 enhanced AR formation was proposed. The rapid formation of ARs in cuttings could be due in part to the induction of IAA biosynthesized by Om19 and also attributed to Trp catalyzed biosynthesis of IAA in plants. AR formation, in turn, provided Om19 preferred sites for colonization. Our study suggested that in addition to promoting AR formation, Om19 could potentially be used as a new biofertilizer for enhancing production of ericaceous plants, such as blueberry, cranberry, and rhododendron.

RevDate: 2021-09-01

Taylor Parkins SK, Murthy S, Picioreanu C, et al (2021)

Multiphysics modelling of photon, mass and heat transfer in coral microenvironments.

Journal of the Royal Society, Interface, 18(182):20210532.

Coral reefs are constructed by calcifying coral animals that engage in a symbiosis with dinoflagellate microalgae harboured in their tissue. The symbiosis takes place in the presence of steep and dynamic gradients of light, temperature and chemical species that are affected by the structural and optical properties of the coral and their interaction with incident irradiance and water flow. Microenvironmental analyses have enabled quantification of such gradients and bulk coral tissue and skeleton optical properties, but the multi-layered nature of corals and its implications for the optical, thermal and chemical microenvironment remains to be studied in more detail. Here, we present a multiphysics modelling approach, where three-dimensional Monte Carlo simulations of the light field in a simple coral slab morphology with multiple tissue layers were used as input for modelling the heat dissipation and photosynthetic oxygen production driven by photon absorption. By coupling photon, heat and mass transfer, the model predicts light, temperature and O2 gradients in the coral tissue and skeleton, under environmental conditions simulating, for example, tissue contraction/expansion, symbiont loss via coral bleaching or different distributions of coral host pigments. The model reveals basic structure-function mechanisms that shape the microenvironment and ecophysiology of the coral symbiosis in response to environmental change.

RevDate: 2021-09-01

Michalik A, Castillo Franco D, Kobiałka M, et al (2021)

Alternative Transmission Patterns in Independently Acquired Nutritional Cosymbionts of Dictyopharidae Planthoppers.

mBio, 12(4):e0122821.

Sap-sucking hemipterans host specialized, heritable microorganisms that supplement their diet with essential nutrients. These microbes show unusual features that provide a unique perspective on the coevolution of host-symbiont systems but are still poorly understood. Here, we combine microscopy with high-throughput sequencing to revisit 80-year-old reports on the diversity of symbiont transmission modes in a broadly distributed planthopper family, Dictyopharidae. We show that in seven species examined, the ancestral nutritional symbionts Sulcia and Vidania producing essential amino acids are complemented by co-primary symbionts, either Arsenophonus or Sodalis, acquired several times independently by different host lineages and contributing to the biosynthesis of B vitamins. These symbionts reside within separate bacteriomes within the abdominal cavity, although in females Vidania also occupies bacteriocytes in the rectal organ. Notably, the symbionts are transovarially transmitted from mothers to offspring in two alternative ways. In most examined species, all nutritional symbionts simultaneously infect the posterior end of the full-grown oocytes and next gather in their perivitelline space. In contrast, in other species, Sodalis colonizes the cytoplasm of the anterior pole of young oocytes, forming a cluster separate from the "symbiont ball" formed by late-invading Sulcia and Vidania. Our results show how newly arriving microbes may utilize different strategies to establish long-term heritable symbiosis. IMPORTANCE Sup-sucking hemipterans host ancient heritable microorganisms that supplement their unbalanced diet with essential nutrients and have repeatedly been complemented or replaced by other microorganisms. These symbionts need to be reliably transmitted to subsequent generations through the reproductive system, and often they end up using the same route as the most ancient ones. We show for the first time that in a single family of planthoppers, the complementing symbionts that have established infections independently utilize different transmission strategies, one of them novel, with the transmission of different microbes separated spatially and temporally. These data show how newly arriving microbes may utilize different strategies to establish long-term heritable symbioses.

RevDate: 2021-08-31

Shikuma NJ (2021)

Bacteria-Stimulated Metamorphosis: an Ocean of Insights from Investigating a Transient Host-Microbe Interaction.

mSystems [Epub ahead of print].

Recent research on host-microbe interactions has focused on intimate symbioses. Yet transient interactions, such as the stimulation of animal metamorphosis by bacteria, can have significant impacts on each partner. During these short-lived interactions, swimming animal larvae identify a desirable location on the seafloor and undergo metamorphosis into a juvenile based on the presence of specific bottom-dwelling bacteria. While this phenomenon is critical for seeding new animals to establish or maintain benthic ecosystems, there is an ocean of fundamental questions that remain unanswered. Here, I propose an updated model of how bacteria stimulate animal metamorphosis based on evidence that bacteria inject a stimulatory protein that prompts tubeworm metamorphosis. I consider what we hope to learn about stimulatory bacterial products, how animals recognize these products, and the consequences for both partners. Finally, I provide examples of how studying an enigmatic host-microbe interaction can serve as an engine for scientific discovery.

RevDate: 2021-08-31
CmpDate: 2021-08-31

Finch JTD, Power SA, Welbergen JA, et al (2021)

Staying in touch: how highly specialised moth pollinators track host plant phenology in unpredictable climates.

BMC ecology and evolution, 21(1):161.

BACKGROUND: For specialised pollinators, the synchrony of plant and pollinator life history is critical to the persistence of pollinator populations. This is even more critical in nursery pollination, where pollinators are obligately dependant on female host plant flowers for oviposition sites. Epicephala moths (Gracillariidae) form highly specialised nursery pollination mutualisms with Phyllanthaceae plants. Several hundred Phyllanthaceae are estimated to be exclusively pollinated by highly specific Epicephala moths, making these mutualisms an outstanding example of plant-insect coevolution. However, there have been no studies of how Epicephala moths synchronise their activity with host plant flowering or persist through periods when flowers are absent. Such knowledge is critical to understanding the ecology and evolutionary stability of these mutualisms. We surveyed multiple populations of both Breynia oblongifolia (Phyllanthaceae) and it's Epicephala pollinators for over two years to determine their phenology and modelled the environmental factors that underpin their interactions.

RESULTS: The abundance of flowers and fruits was highly variable and strongly linked to local rainfall and photoperiod. Unlike male flowers and fruits, female flowers were present throughout the entire year, including winter. Fruit abundance was a significant predictor of adult Epicephala activity, suggesting that eggs or early instar larvae diapause within dormant female flowers and emerge as fruits mature. Searches of overwintering female flowers confirmed that many contained pollen and diapausing pollinators. We also observed diapause in Epicephala prior to pupation, finding that 12% (9/78) of larvae emerging from fruits in the autumn entered an extended diapause for 38-48 weeks. The remaining autumn emerging larvae pupated directly without diapause, suggesting a possible bet-hedging strategy.

CONCLUSIONS: Epicephala appear to use diapause at multiple stages in their lifecycle to survive variable host plant phenology. Furthermore, moth abundance was predicted by the same environmental variables as male flowers, suggesting that moths track flowering through temperature. These adaptations may thereby mitigate against unpredictability in the timing of fruiting and flowering because of variable rainfall. It remains to be seen how widespread egg diapause and pre-pupal diapause may be within Epicephala moths, and, furthermore, to what degree these traits may have facilitated the evolution of these highly diverse mutualisms.

RevDate: 2021-08-31
CmpDate: 2021-08-31

Rahal S, D Chekireb (2021)

Diversity of rhizobia and non-rhizobia endophytes isolated from root nodules of Trifolium sp. growing in lead and zinc mine site Guelma, Algeria.

Archives of microbiology, 203(7):3839-3849.

High concentrations of heavy metals in mine soil disturb the interactions between legumes and microorganisms leading to select strains adapted to these specific conditions. In this work, we analyzed the diversity of fifty strains isolated from Trifolium sp. nodules growing on Pb-Zn mine soil, in the Northeastern of Algeria and highlighted their potential symbiotic traits. The phylogeny of the 16S rRNA gene sequences revealed a high bacterial diversity with a predominance of non-rhizobial endophytes. The identified isolates belong to the thirteen following genera Cupriavidus, Pseudomonas, Bacillus, Acinetobacter, Enterobacter, Roseomonas, Paracoccus, Frondihabitans, Microbacterium, Kocuria, Providencia, Micrococcus and Staphylococcus. Regarding rhizobial strains, only isolates affiliated to Rhizobium genus were obtained. The symbiotic gene nodC and the nitrogen fixation gene nifH present showed that Rhizobium isolates belonged to the symbiovar trifolii. In addition to bacterial, one yeast strain was isolated and identified as Rhodotorula mucilaginosa by sequencing the internal transcribed spacer (ITS) region.

RevDate: 2021-08-31
CmpDate: 2021-08-31

Dokwal D, Romsdahl TB, Kunz DA, et al (2021)

Phosphorus deprivation affects composition and spatial distribution of membrane lipids in legume nodules.

Plant physiology, 185(4):1847-1859.

In legumes, symbiotic nitrogen (N) fixation (SNF) occurs in specialized organs called nodules after successful interactions between legume hosts and rhizobia. In a nodule, N-fixing rhizobia are surrounded by symbiosome membranes, through which the exchange of nutrients and ammonium occurs between bacteria and the host legume. Phosphorus (P) is an essential macronutrient, and N2-fixing legumes have a higher requirement for P than legumes grown on mineral N. As in the previous studies, in P deficiency, barrel medic (Medicago truncatula) plants had impaired SNF activity, reduced growth, and accumulated less phosphate in leaves, roots, and nodules compared with the plants grown in P sufficient conditions. Membrane lipids in M. truncatula tissues were assessed using electrospray ionization-mass spectrometry. Galactolipids were found to increase in P deficiency, with declines in phospholipids (PL), especially in leaves. Lower PL losses were found in roots and nodules. Subsequently, matrix-assisted laser desorption/ionization-mass spectrometry imaging was used to spatially map the distribution of the positively charged phosphatidylcholine (PC) species in nodules in both P-replete and P-deficient conditions. Our results reveal heterogeneous distribution of several PC species in nodules, with homogeneous distribution of other PC classes. In P poor conditions, some PC species distributions were observed to change. The results suggest that specific PC species may be differentially important in diverse nodule zones and cell types, and that membrane lipid remodeling during P stress is not uniform across the nodule.

RevDate: 2021-08-31
CmpDate: 2021-08-31

Larsen SB, S Naik (2021)

A neu(ronal) player joins the T regulatory game.

Immunity, 54(3):404-406.

The enteric nervous system is surfacing as a key regulator of intestinal immunity and a liaison of host-commensal interactions. In this issue, Yan et al. identify neuronal interleukin-6 as a potent modulator of regulatory T (Treg) cells in the intestine. This neuroimmune dialog is further refined by commensal microbiota, which impact the enteric nervous system and consequently the intestinal Treg cell pool.

RevDate: 2021-08-31
CmpDate: 2021-08-31

Ainsworth TD, BE Brown (2021)

Coral bleaching.

Current biology : CB, 31(1):R5-R6.

Tracy Ainsworth and Barbara Brown introduce the causes and consequences of coral bleaching.

RevDate: 2021-08-31
CmpDate: 2021-08-31

Berbee ML, Strullu-Derrien C, Delaux PM, et al (2020)

Genomic and fossil windows into the secret lives of the most ancient fungi.

Nature reviews. Microbiology, 18(12):717-730.

Fungi have crucial roles in modern ecosystems as decomposers and pathogens, and they engage in various mutualistic associations with other organisms, especially plants. They have a lengthy geological history, and there is an emerging understanding of their impact on the evolution of Earth systems on a large scale. In this Review, we focus on the roles of fungi in the establishment and early evolution of land and freshwater ecosystems. Today, questions of evolution over deep time are informed by discoveries of new fossils and evolutionary analysis of new genomes. Inferences can be drawn from evolutionary analysis by comparing the genes and genomes of fungi with the biochemistry and development of their plant and algal hosts. We then contrast this emerging picture against evidence from the fossil record to develop a new, integrated perspective on the origin and early evolution of fungi.

RevDate: 2021-08-30

Tian L, Liu L, Xu S, et al (2021)

A D-pinitol transporter, LjPLT11, regulates plant growth and nodule development in Lotus japonicus.

Journal of experimental botany pii:6359879 [Epub ahead of print].

Polyol transporters (PLTs) have been functionally characterized in yeast and Xenopus laevis oocytes as H +-symporters with broad substrate specificity, but little is known about their physiological roles in planta. To extend this knowledge we investigated roles of LjPLT11 in Lotus japonicus-Mesorhizobium symbiosis. Functional analyses of the LjPLT11 in yeast characterized this protein as an energy-independent transporter of xylitol, two O-methyl inositols, xylose and galactose. We also showed that LjPLT11 is located on peribacteroid membranes (PBMs) and functions as a facilitative transporter of D-pinitol within infected cells of L. japonicus nodules. Knockdown of LjPLT11 (LjPLT11i) in L. japonicus accelerated plant growth under nitrogen-sufficiency, but resulted in abnormal bacteroids with corresponding reductions in nitrogenase activity in nodules and plant growth in the nitrogen-fixing symbiosis. LjPLT11i nodules had higher osmotic pressure in cytosol and fewer in bacteroids than wildtype nodules both three and four weeks after inoculation of M. loti. Levels and distributions of reactive oxygen species were also perturbed in infected cells of four-week-old nodules in LjPLT11i plants. The results indicate that LjPLT11 plays a key role in adjustment of levels of its substrate pinitol, and thus maintenance of osmotic balance in infected cells and PBM stability during nodule development.

RevDate: 2021-08-30

Wang S, Xia J, De Paepe K, et al (2021)

Ultra-high Pressure Treatment Controls In Vitro Fecal Fermentation Rate of Insoluble Dietary Fiber from Rosa Roxburghii Tratt Pomace and Induces Butyrogenic Shifts in Microbiota Composition.

Journal of agricultural and food chemistry [Epub ahead of print].

Dietary fiber has been considered a key element in shaping the beneficial host-microbe symbiosis. In the present study, we identified Rosa roxburghii Tratt fruits as a promising dietary fiber source. The physicochemical properties and in vitro fermentability by human fecal microbes of R. roxburghii pomace water insoluble dietary fiber (RIDF) obtained from ultrasonic extraction and ultrahigh pressure (90 MPa)-treated RIDF (RIDF-90) were compared to those of R. roxburghii Tratt pomace (R). Ultrahigh pressure modification significantly increased the water holding, oil holding, and swelling capacity of RIDF-90 in comparison to R and RIDF. RIDF-90 displayed the slowest fermentation rate yet yielded the highest butyrate production. The superior butyrogenic properties of both RIDF-90 and, in part, RIDF were reflected by increased Coprococcus and Ruminococcus levels, demonstrating that ultrasonic extraction and/or further ultrahigh pressure treatment of insoluble fibers promotes the prebiotic value of R. roxburghii Tratt.

RevDate: 2021-08-30

Ganesan R, Kaltenpoth M, LV Flórez (2021)

Transposon-insertion Sequencing as a Tool to Elucidate Bacterial Colonization Factors in a Burkholderia gladioli Symbiont of Lagria villosa Beetles.

Journal of visualized experiments : JoVE.

Inferring the function of genes by manipulating their activity is an essential tool for understanding the genetic underpinnings of most biological processes. Advances in molecular microbiology have seen the emergence of diverse mutagenesis techniques for the manipulation of genes. Among them, transposon-insertion sequencing (Tn-seq) is a valuable tool to simultaneously assess the functionality of many candidate genes in an untargeted way. The technique has been key to identify molecular mechanisms for the colonization of eukaryotic hosts in several pathogenic microbes and a few beneficial symbionts. Here, Tn-seq is established as a method to identify colonization factors in a mutualistic Burkholderia gladioli symbiont of the beetle Lagria villosa. By conjugation, Tn5 transposon-mediated insertion of an antibiotic-resistance cassette is carried out at random genomic locations in B. gladioli. To identify the effect of gene disruptions on the ability of the bacteria to colonize the beetle host, the generated B. gladioli transposon-mutant library is inoculated on the beetle eggs, while a control is grown in vitro in a liquid culture medium. After allowing sufficient time for colonization, DNA is extracted from the in vivo and in vitro grown libraries. Following a DNA library preparation protocol, the DNA samples are prepared for transposon-insertion sequencing. DNA fragments that contain the transposon-insert edge and flanking bacterial DNA are selected, and the mutation sites are determined by sequencing away from the transposon-insert edge. Finally, by analyzing and comparing the frequencies of each mutant between the in vivo and in vitro libraries, the importance of specific symbiont genes during beetle colonization can be predicted.

RevDate: 2021-08-30

Prakash O, Parmar M, Vaijanapurkar M, et al (2021)

Recent trend, biases, and limitations of cultivation based diversity studies of microbes.

FEMS microbiology letters pii:6359716 [Epub ahead of print].

The current study attempts to analyze recent trends, biases, and limitations of cultivation based microbial diversity studies based on published, novel species in the past six years in the International Journal of Systematic and Evolutionary Microbiology (IJSEM), an official publication of the International Committee on Systematics of Prokaryotes (ICSP) and the Bacteriology and Applied Microbiology (BAM) Division of the International Union of Microbiological Societies (IUMS). IJSEM deals with taxa that have validly published names under the International Code of Nomenclature of Prokaryotes (ICNP). All the relevant publications from the last six years were retrieved, sorted, and analyzed to get the answers to What is the current rate of novel species description? Which country has contributed substantially and which phyla represented better in culturable diversity studies? What are the current limitations? Published data for the past 6 years indicate that 500-900 novel species are reported annually. China, Korea, Germany, United Kingdom, India, and the USA are at the forefront while contributions from other nations are meager. Despite the recent development in culturomics tools the dominance of Proteobacteria, Bacteroidetes and Actinobacteria are still prevalent in cultivation, while the representation of archaea, obligate anaerobes, microaerophiles, synergistic symbionts, aerotolerant, and other fastidious microbes is poor. Single strain-based taxonomic descriptions prevail and emphasis on objective-based cultivation for biotechnological and environmental significance is not- yet conspicuous.

RevDate: 2021-08-30

Huang HH, Si J, Brandt A, et al (2021)

Taking Both Sides: Seeking Symbiosis Between Intelligent Prostheses and Human Motor Control during Locomotion.

Current opinion in biomedical engineering, 20:.

Robotic lower-limb prostheses aim to replicate the power-generating capability of biological joints during locomotion to empower individuals with lower-limb loss. However, recent clinical trials have not demonstrated clear advantages of these devices over traditional passive devices. We believe this is partly because the current designs of robotic prothesis controllers and clinical methods for fitting and training individuals to use them do not ensure good coordination between the prosthesis and user. Accordingly, we advocate for new holistic approaches in which human motor control and intelligent prosthesis control function as one system (defined as human-prosthesis symbiosis). We hope engineers and clinicians will work closely to achieve this symbiosis, thereby improving the functionality and acceptance of robotic prostheses and users' quality of life.

RevDate: 2021-08-30

Wechsler H (2021)

Immunity and security using holism, ambient intelligence, triangulation, and stigmergy: Sensitivity analysis confronts fake news and COVID-19 using open set transduction.

Journal of ambient intelligence and humanized computing pii:3434 [Epub ahead of print].

This paper introduces a multi-faceted security methodology based on Holism, Ambient Intelligence, Triangulation, and Stigmergy (HATS) to combat the spread of current pandemics such as fake news and COVID-19. HATS leverages the apparent complementarity and similarity of physical and mental pandemics using adversarial learning and transduction to promote immunity on both using conformal prediction and principled symbiosis. As such, HATS confronts both mental and physical adversity found in misinformation and disinformation. It confers herd immunity using holism and triangulation that call to advantage on sensitivity analysis using open set transduction and meta-reasoning. Ambient intelligence and stigmergy further mediate meta-reasoning and re-identification in building and sharing immunity. As change is constant and everything is fluid, as truth is not always reality and reality is not always truth, and as truth is imponderable and lie can become truth, two things have to happen. First, reconditioning and reconfiguration engage random deficiency to discern familiarity from strangeness and a-typicality. Second, transfer learning using trans-adaptation and transposition, serve adaptation and interoperability. Together, this empowers open set transduction in facing adaptive persistent threats such as deception and denial when it engages moving target defense using modification and de-identification. Immunology and security further come together using to advantage the coupling of active and adversarial learning.

RevDate: 2021-08-30

Dijkhuizen LW, Tabatabaei BES, Brouwer P, et al (2021)

Far-Red Light-Induced Azolla filiculoides Symbiosis Sexual Reproduction: Responsive Transcripts of Symbiont Nostoc azollae Encode Transporters Whilst Those of the Fern Relate to the Angiosperm Floral Transition.

Frontiers in plant science, 12:693039.

Water ferns of the genus Azolla and the filamentous cyanobacteria Nostoc azollae constitute a model symbiosis that enabled the colonization of the water surface with traits highly desirable for the development of more sustainable crops: their floating mats capture CO2 and fix N2 at high rates using light energy. Their mode of sexual reproduction is heterosporous. The regulation of the transition from the vegetative phase to the spore forming phase in ferns is largely unknown, yet a prerequisite for Azolla domestication, and of particular interest as ferns represent the sister lineage of seed plants. Sporocarps induced with far red light could be crossed so as to verify species attribution of strains from the Netherlands but not of the strain from the Anzali lagoon in Iran; the latter strain was assigned to a novel species cluster from South America. Red-dominated light suppresses the formation of dissemination stages in both gametophyte- and sporophyte-dominated lineages of plants, the response likely is a convergent ecological strategy to open fields. FR-responsive transcripts included those from MIKCC homologues of CMADS1 and miR319-controlled GAMYB transcription factors in the fern, transporters in N. azollae, and ycf2 in chloroplasts. Loci of conserved microRNA (miRNA) in the fern lineage included miR172, yet FR only induced miR529 and miR535, and reduced miR319 and miR159. Phylogenomic analyses of MIKCC TFs suggested that the control of flowering and flower organ specification may have originated from the diploid to haploid phase transition in the homosporous common ancestor of ferns and seed plants.

RevDate: 2021-08-30
CmpDate: 2021-08-30

van der Kooi CJ, Vallejo-Marín M, SD Leonhardt (2021)

Mutualisms and (A)symmetry in Plant-Pollinator Interactions.

Current biology : CB, 31(2):R91-R99.

The majority of flowering plants relies on animal pollinators for sexual reproduction and many animal pollinators rely on floral resources. However, interests of plants and pollinators are often not the same, resulting in an asymmetric relationship that ranges from mutualistic to parasitic interactions. Our understanding of the processes that underlie this asymmetry remains fragmentary. In this Review, we bring together evidence from evolutionary biology, plant chemistry, biomechanics, sensory ecology and behaviour to illustrate that the degree of symmetry often depends on the perspective taken. We also highlight variation in (a)symmetry within and between plant and pollinator species as well as between geographic locations. Through taking different perspectives from the plant and pollinator sides we provide new ground for studies on the maintenance and evolution of animal pollination and on the (a)symmetry in plant-pollinator interactions.

RevDate: 2021-08-30
CmpDate: 2021-08-30

Díaz-Sánchez S, Fernández AM, Habela MA, et al (2021)

Microbial community of Hyalomma lusitanicum is dominated by Francisella-like endosymbiont.

Ticks and tick-borne diseases, 12(2):101624.

Exploring tick associations with complex microbial communities and single-microbial partners, especially intracellular symbionts, has become crucial to understand tick biology. Of particular interest are the underlying interactions with biological consequences i.e. tick fitness, vector competence. In this study, we first sequenced the 16S rRNA bacterial phylogenetic marker in adult male ticks of Hyalomma lusitanicum collected from 5 locations in the province of Cáceres to explore the composition of its microbial community. Overall, 16S rRNA sequencing results demonstrated that the microbial community of H. lusitanicum is mostly dominated by Francisella-like endosymbionts (FLEs) (ranging from 52% to 99% of relative abundance) suggesting it is a key taxon within the microbial community and likely a primary endosymbiont. However, further research is required to explore the mechanisms underlying the interaction between FLEs and H. lusitanicum.

RevDate: 2021-08-30
CmpDate: 2021-08-30

Rodrigues AMM, Estrela S, SP Brown (2021)

Community lifespan, niche expansion and the evolution of interspecific cooperation.

Journal of evolutionary biology, 34(2):352-363.

Microbes live in dense and diverse communities where they deploy many traits that promote the growth and survival of neighbouring species, all the while also competing for shared resources. Because microbial communities are highly dynamic, the costs and benefits of species interactions change over the growth cycle of a community. How mutualistic interactions evolve under such demographic and ecological conditions is still poorly understood. Here, we develop an eco-evolutionary model to explore how different forms of helping with distinct fitness effects (rate-enhancing and yield-enhancing) affect the multiple phases of community growth, and its consequences for the evolution of mutualisms. We specifically focus on a form of yield-enhancing trait in which cooperation augments the common pool of resources, termed niche expansion. We show that although mutualisms in which cooperation increases partners growth rate are generally favoured at early stages of community growth, niche expansion can evolve at later stages where densities are high. Further, we find that niche expansion can promote the evolution of reproductive restraint, in which a focal species adaptively reduces its own growth rate to increase the density of partner species. Our findings suggest that yield-enhancing mutualisms are more prevalent in stable habitats with a constant supply of resources, and where populations typically live at high densities. In general, our findings highlight the need to integrate different components of population growth in the analysis of mutualisms to understand the composition and function of microbial communities.

RevDate: 2021-08-30
CmpDate: 2021-08-30

Prigot-Maurice C, de Cerqueira De Araujo A, Beltran-Bech S, et al (2021)

Immune priming depends on age, sex and Wolbachia in the interaction between Armadillidium vulgare and Salmonella.

Journal of evolutionary biology, 34(2):256-269.

The protection conferred by a first infection upon a second pathogenic exposure (i.e. immune priming) is an emergent research topic in the field of invertebrate immunity. Immune priming has been demonstrated in various species, but little is known about the intrinsic factors that may influence this immune process. In this study, we tested whether age, gender and the symbiotic bacterium Wolbachia affect the protection resulting from immune priming in A. vulgare against S. enterica. We firstly primed young and old, symbiotic and asymbiotic males and females, either with a non-lethal low dose of S. enterica, LB broth or without injection (control). Seven days post-injection, we performed a LD50 injection of S. enterica in all individuals and we monitored their survival rates. We demonstrated that survival capacities depend on these three factors: young and old asymbiotic individuals (males and females) expressed immune priming (S. enterica-primed individuals survived better than LB-primed and non-primed), with a general decline in the strength of protection in old females, but not in old males, compared to young. When Wolbachia is present, the immune priming protection was observed in old, but not in young symbiotic individuals, even if the Wolbachia load on entire individuals is equivalent regardless to age. Our overall results showed that the immune priming protection in A. vulgare depends on individuals' states, highlighting the need to consider these factors both in mechanistical and evolutionary studies focusing on invertebrate's immunity.

RevDate: 2021-08-30
CmpDate: 2021-08-30

Kamal SM, Cimdins-Ahne A, Lee C, et al (2021)

A recently isolated human commensal Escherichia coli ST10 clone member mediates enhanced thermotolerance and tetrathionate respiration on a P1 phage-derived IncY plasmid.

Molecular microbiology, 115(2):255-271.

The ubiquitous human commensal Escherichia coli has been well investigated through its model representative E. coli K-12. In this work, we initially characterized E. coli Fec10, a recently isolated human commensal strain of phylogroup A/sequence type ST10. Compared to E. coli K-12, the 4.88 Mbp Fec10 genome is characterized by distinct single-nucleotide polymorphisms and acquisition of genomic islands. In addition, E. coli Fec10 possesses a 155.86 kbp IncY plasmid, a composite element based on phage P1. pFec10 harbours multiple cargo genes such as coding for a tetrathionate reductase and its corresponding regulatory two-component system. Among the cargo genes is also the Transmissible Locus of Protein Quality Control (TLPQC), which mediates tolerance to lethal temperatures in bacteria. The disaggregase ClpGGI of TLPQC constitutes a major determinant of the thermotolerance of E. coli Fec10. We confirmed stand-alone disaggregation activity, but observed distinct biochemical characteristics of ClpGGI-Fec10 compared to the nearly identical Pseudomonas aeruginosa ClpGGI-SG17M. Furthermore, we noted a unique contribution of ClpGGI-Fec10 to the exquisite thermotolerance of E. coli Fec10, suggesting functional differences between both disaggregases in vivo. Detection of thermotolerance in 10% of human commensal E. coli isolates hints to the successful establishment of food-borne heat-resistant strains in the human gut.

RevDate: 2021-08-30
CmpDate: 2021-08-30

Daisley BA, Chmiel JA, Pitek AP, et al (2020)

Missing Microbes in Bees: How Systematic Depletion of Key Symbionts Erodes Immunity.

Trends in microbiology, 28(12):1010-1021.

Pesticide exposure, infectious disease, and nutritional stress contribute to honey bee mortality and a high rate of colony loss. This realization has fueled a decades-long investigation into the single and combined effects of each stressor and their overall bearing on insect physiology. However, one element largely missing from this research effort has been the evaluation of underlying microbial communities in resisting environmental stressors and their influence on host immunity and disease tolerance. In humans, multigenerational bombardment by antibiotics is linked with many contemporary diseases. Here, we draw a parallel conclusion for the case in honey bees and suggest that chronic exposure to antimicrobial xenobiotics can systematically deplete honey bees of their microbes and hamper cross-generational preservation of host-adapted symbionts that are crucial to health.

RevDate: 2021-08-28

Singh P, Kadam V, Y Patil (2021)

Isolation and development of a microbial consortium for the treatment of automobile service station wastewater.

Journal of applied microbiology [Epub ahead of print].

AIM: This work aims to investigate the nature of waste being generated by automobile service stations (ASS) and to devise a microbial-based formulation for the treatment of ASS wastewater.

METHODS AND RESULTS: Analysis of soil and water samples from the vicinity of different ASS in and around the Pune city region (India) revealed the presence of significant amounts of many heavy metals including zinc (Zn) 13.8-175.44 mg kg-1 , nickel (Ni) 0.6-5.5 mg kg-1 and copper (Cu) 8.07-179.2 mg kg-1 as well as oil and grease (O&G). A consortium, consisting of selected members from the ASS soil bacterial isolates, was formulated. The selection of consortium members was based on their ability to degrade hydrocarbons, tolerate heavy metals, and produce biosurfactant and lipase. The developed microbial consortium was capable of reducing the concentration of Ni, manganese (Mn) and chromium (Cr) by 69.25%, 14.63% and 84.93%, respectively, and O&G by 71.8% in the aqueous medium under laboratory conditions.

CONCLUSIONS: Wastewater and soil analysis confirmed the presence of a high amount of O&G and metals in and around ASS. The developed microbial consortium holds potential for the treatment of wastewater rich in O&G and heavy metals.

There is a dearth of scientific studies in India on the wastewater and polluted soils associated with ASS. This work reveals and confirms the hazardous nature of ASS and the need for the development and feasibility of microbial-based technology for the sustainable bioremediation of such sites.

RevDate: 2021-08-28

Le Quéré A, Diop S, Dehaene N, et al (2021)

Development of an Illumina-based analysis method to study bradyrhizobial population structure-case study on nitrogen-fixing rhizobia associating with cowpea or peanut.

Applied microbiology and biotechnology [Epub ahead of print].

Bradyrhizobia are Gram-negative soil bacteria that regroup a growing number of species. They are widespread in nature and recovered from various biomes that may be explained by a high genetic diversity in this genus. Among the numerous metabolic properties they can harbor, the nitrogen fixation resulting from the association with plants among which important crop legumes (soya bean, peanut, cowpea …) is of great interest, notably in a context of sustainable development. Metabarcoding is widely applied to study biodiversity from complex microbial communities. Here, we demonstrate that using a new species-specific and highly polymorphic 16S-23S rRNA intergenic spacer barcode, we could rapidly estimate the diversity of bradyrhizobial populations that associate with cowpea and peanut plants, two crop legumes of major interest in Senegal. Application of the method on indigenous bradyrhizobia associated with peanut and cowpea grown in soils collected in the center of the peanut basin shows that Bradyrhizobium vignae is a dominant symbiont. We also showed that the two plant species associate with distinct community profiles and that strains introduced by inoculation significantly modified the population structure with these two plants suggesting that application of elite strains as inoculants may well ensure optimized symbiotic performance. This approach may further be used to study the diversity of bradyrhizobia from contrasting agro-eco-climatic zones, to test whether the plant genotype influences the association outputs as well as to estimate the competitiveness for nodule occupancy and the fate of elite strains inoculated in the field.Key points• An amplicon sequencing approach targeting the Bradyrhizobium genus was developed.• Diversity of cowpea and peanut bradyrhizobia from cultivated soils was identified.• The method is well suited to test the competitiveness of defined Bradyrhizobium inoculants.


ESP Quick Facts

ESP Origins

In the early 1990's, Robert Robbins was a faculty member at Johns Hopkins, where he directed the informatics core of GDB — the human gene-mapping database of the international human genome project. To share papers with colleagues around the world, he set up a small paper-sharing section on his personal web page. This small project evolved into The Electronic Scholarly Publishing Project.

ESP Support

In 1995, Robbins became the VP/IT of the Fred Hutchinson Cancer Research Center in Seattle, WA. Soon after arriving in Seattle, Robbins secured funding, through the ELSI component of the US Human Genome Project, to create the original ESP.ORG web site, with the formal goal of providing free, world-wide access to the literature of classical genetics.

ESP Rationale

Although the methods of molecular biology can seem almost magical to the uninitiated, the original techniques of classical genetics are readily appreciated by one and all: cross individuals that differ in some inherited trait, collect all of the progeny, score their attributes, and propose mechanisms to explain the patterns of inheritance observed.

ESP Goal

In reading the early works of classical genetics, one is drawn, almost inexorably, into ever more complex models, until molecular explanations begin to seem both necessary and natural. At that point, the tools for understanding genome research are at hand. Assisting readers reach this point was the original goal of The Electronic Scholarly Publishing Project.

ESP Usage

Usage of the site grew rapidly and has remained high. Faculty began to use the site for their assigned readings. Other on-line publishers, ranging from The New York Times to Nature referenced ESP materials in their own publications. Nobel laureates (e.g., Joshua Lederberg) regularly used the site and even wrote to suggest changes and improvements.

ESP Content

When the site began, no journals were making their early content available in digital format. As a result, ESP was obliged to digitize classic literature before it could be made available. For many important papers — such as Mendel's original paper or the first genetic map — ESP had to produce entirely new typeset versions of the works, if they were to be available in a high-quality format.

ESP Help

Early support from the DOE component of the Human Genome Project was critically important for getting the ESP project on a firm foundation. Since that funding ended (nearly 20 years ago), the project has been operated as a purely volunteer effort. Anyone wishing to assist in these efforts should send an email to Robbins.

ESP Plans

With the development of methods for adding typeset side notes to PDF files, the ESP project now plans to add annotated versions of some classical papers to its holdings. We also plan to add new reference and pedagogical material. We have already started providing regularly updated, comprehensive bibliographies to the ESP.ORG site.

Electronic Scholarly Publishing
961 Red Tail Lane
Bellingham, WA 98226

E-mail: RJR8222 @

Papers in Classical Genetics

The ESP began as an effort to share a handful of key papers from the early days of classical genetics. Now the collection has grown to include hundreds of papers, in full-text format.

Digital Books

Along with papers on classical genetics, ESP offers a collection of full-text digital books, including many works by Darwin (and even a collection of poetry — Chicago Poems by Carl Sandburg).


ESP now offers a much improved and expanded collection of timelines, designed to give the user choice over subject matter and dates.


Biographical information about many key scientists.

Selected Bibliographies

Bibliographies on several topics of potential interest to the ESP community are now being automatically maintained and generated on the ESP site.

ESP Picks from Around the Web (updated 07 JUL 2018 )