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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 14 Nov 2022 at 02:06 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: 2022-11-09

Blanckaert ACA, Grover R, Marcus MI, et al (2022)

Nutrient starvation and nitrate pollution impairs the assimilation of dissolved organic phosphorus in coral-Symbiodiniaceae symbiosis.

The Science of the total environment pii:S0048-9697(22)07044-9 [Epub ahead of print].

Phosphorus (P) is an essential but limiting nutrient for coral growth due to low concentrations of dissolved inorganic concentrations (DIP) in reef waters. P limitation is often exacerbated when concentrations of dissolved inorganic nitrogen (DIN) increase in the reef. To increase their access to phosphorus, corals can use organic P dissolved in seawater (DOP). They possess phosphatase enzymes that transform DOP into DIP, which can then be taken up by coral symbionts. Although the concentration of DOP in reef waters is much higher than DIP, the dependence of corals on this P source is still poorly understood, especially with different concentrations of DIN in seawater. As efforts to predict the future of corals increase, improved knowledge of the P requirements of corals living under different DIN concentrations may be key to predicting coral health. In this study, we investigated P content and phosphatase activities (PAs) in Stylophora pistillata maintained under nutrient starvation, long-term nitrogen enrichment (nitrate or ammonium at 2 μM) and short-term (few hours) nitrogen pulses. Results show that under nutrient depletion and ammonium-enriched conditions, a significant increase in PAs was observed compared to control conditions, with no change in the N:P ratio of the coral tissue. On the contrary, under nitrate enrichment, there was no increase in PAs compared to control conditions, but an increase in the N:P ratio of the coral tissue. These results suggest that under nitrate enrichment, corals were unable to increase their ability to rely on DOP and replenish their cellular P content. An increase in cellular N:P ratio is detrimental to coral health as it increases the susceptibility of coral bleaching under thermal stress. These results provide an overall view of the P requirements of corals exposed to different nutrient conditions and improve our understanding of the effects of nitrogen enrichment on corals.

RevDate: 2022-11-09

Altamia MA, DL Distel (2022)

Transport of symbiont-encoded cellulases from the gill to the gut of shipworms via the enigmatic ducts of Deshayes: a 174-year mystery solved.

Proceedings. Biological sciences, 289(1986):20221478.

Shipworms (Bivalvia, Teredinidae) are the principal consumers of wood in marine environments. Like most wood-eating organisms, they digest wood with the aid of cellulolytic enzymes supplied by symbiotic bacteria. However, in shipworms the symbiotic bacteria are not found in the digestive system. Instead, they are located intracellularly in the gland of Deshayes, a specialized tissue found within the gills. It has been independently demonstrated that symbiont-encoded cellulolytic enzymes are present in the digestive systems and gills of two shipworm species, Bankia setacea and Lyrodus pedicellatus, confirming that these enzymes are transported from the gills to the lumen of the gut. However, the mechanism of enzyme transport from gill to gut remains incompletely understood. Recently, a mechanism was proposed by which enzymes are transported within bacterial cells that are expelled from the gill and transported to the mouth by ciliary action of the branchial or food grooves. Here we use in situ immunohistochemical methods to provide evidence for a different mechanism in the shipworm B. setacea, in which cellulolytic enzymes are transported via the ducts of Deshayes, enigmatic structures first described 174 years ago, but whose function have remained unexplained.

RevDate: 2022-11-08

Rasmussen N (2022)

René Dubos, the Autochthonous Flora, and the Discovery of the Microbiome.

Journal of the history of biology [Epub ahead of print].

Now characterised by high-throughput sequencing methods that enable the study of microbes without lab culture, the human "microbiome" (the microbial flora of the body) is said to have revolutionary implications for biology and medicine. According to many experts, we must now understand ourselves as "holobionts" like lichen or coral, multispecies superorganisms that consist of animal and symbiotic microbes in combination, because normal physiological function depends on them. Here I explore the 1960s research of biologist René Dubos, a forerunner figure mentioned in some historical accounts of the microbiome, and argue that he arrived at the superorganism concept 40 years before the Human Microbiome Project. This raises the question of why his contribution was not hailed as revolutionary at the time and why Dubos is not remembered for it.

RevDate: 2022-11-09
CmpDate: 2022-11-09

Turelli M, Katznelson A, PS Ginsberg (2022)

Why Wolbachia-induced cytoplasmic incompatibility is so common.

Proceedings of the National Academy of Sciences of the United States of America, 119(47):e2211637119.

Cytoplasmic incompatibility (CI) is the most common reproductive manipulation produced by Wolbachia, obligately intracellular alphaproteobacteria that infect approximately half of all insect species. Once infection frequencies within host populations approach 10%, intense CI can drive Wolbachia to near fixation within 10 generations. However, natural selection among Wolbachia variants within individual host populations does not favor enhanced CI. Indeed, variants that do not cause CI but increase host fitness or are more reliably maternally transmitted are expected to spread if infected females remain protected from CI. Nevertheless, approximately half of analyzed Wolbachia infections cause detectable CI. Why? The frequency and persistence of CI are more plausibly explained by preferential spread to new host species (clade selection) rather than by natural selection among variants within host populations. CI-causing Wolbachia lineages preferentially spread into new host species because 1) CI increases equilibrium Wolbachia frequencies within host populations, and 2) CI-causing variants can remain at high frequencies within populations even when conditions change so that initially beneficial Wolbachia infections become harmful. An epidemiological model describing Wolbachia acquisition and loss by host species and the loss of CI-induction within Wolbachia lineages yields simple expressions for the incidence of Wolbachia infections and the fraction of those infections causing CI. Supporting a determinative role for differential interspecific spread in maintaining CI, many Wolbachia infections were recently acquired by their host species, many show evidence for contemporary spatial spread or retreat, and rapid evolution of CI-inducing loci, especially degradation, is common.

RevDate: 2022-11-08

Qin J, J Wu (2022)

Realizing the Potential of Computer-Assisted Surgery by Embedding Digital Twin Technology.

JMIR medical informatics, 10(11):e35138 pii:v10i11e35138.

The value of virtual world and digital phenotyping has been demonstrated in several fields, and their applications in the field of surgery are worthy of attention and exploration. This viewpoint describes the necessity and approach to understanding the deeper potential of computer-assisted surgery through interaction and symbiosis between virtual and real spaces. We propose to embed digital twin technology into all aspects of computer-assisted surgery rather than just the surgical object and further apply it to the whole process from patient treatment to recovery. A more personalized, precise, and predictable surgery is our vision.

RevDate: 2022-11-08

Peterson LS, K Scheible (2022)

Leveraging Microbial Symbiosis to Modulate Bronchopulmonary Dysplasia.

American journal of respiratory cell and molecular biology [Epub ahead of print].

RevDate: 2022-11-08

Horning AL, Koury SS, Meachum M, et al (2022)

Dirt cheap: An experimental test of controls on resource exchange in an ectomycorrhizal symbiosis.

The New phytologist [Epub ahead of print].

To distinguish among hypotheses on the importance of resource-exchange ratios in outcomes of mutualisms, we measured resource (carbon (C), nitrogen (N), and phosphorus (P)) transfers, and their ratios, between Pinus taeda seedlings and two ectomycorrhizal (EM) fungal species, Rhizopogon roseolus and Pisolithus arhizus in a laboratory experiment. We evaluated how ambient light affected those resource fluxes and ratios over 3 time periods (10, 20, and 30 weeks), and the consequences for plant and fungal biomass accrual, in environmental chambers. Our results suggest that light availability is an important factor driving absolute fluxes of N, P, and C, but not exchange ratios, although its effects vary among EM fungal species. Declines in N:C and P:C exchange ratios over time, as soil nutrient availability likely declined, were consistent with predictions of biological market models. Absolute transfer of P was an important predictor of both plant and fungal biomass, consistent with the excess resource exchange hypothesis, and N transfer to plants was positively associated with fungal biomass. Altogether, light effects on resource fluxes indicated mixed support for various theoretical frameworks, while results on biomass accrual better supported the excess resource exchange hypothesis, although among-species variability is in need of further characterization.

RevDate: 2022-11-08

Fajal S, Hassan A, Mandal W, et al (2022)

Ordered Macro/Microporous Ionic Organic Framework for Efficient Separation of Toxic Pollutants from Water.

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

In case of pollutant segregation fast mass diffusion is a fundamental criterion in order to achieve improved performance. The rapid mass transport through porous materials can be achieved by availing large open pores followed by easy and complete accessibility of functional sites. Inducing macroporosity into such materials could serve as ideal solution providing access to large macropores that offer unhindered transport of analyte and full exposure to interactive sites. Moreover, the challenge to configure the ionic-functionality with macroporosity could emerge as an unparalleled avenue toward pollutants separation. Herein, we strategized a synthetic protocol for construction of a positively charged hierarchically-porous ordered interconnected macro-structure of organic framework where the size and number of macropores can easily be tuned. The ordered macropores with strong electrostatic interaction synergistically exhibited ultrafast removal efficiency toward various toxic pollutants.

RevDate: 2022-11-07

Bhat CG, Budhwar R, Godwin J, et al (2022)

RNA-Sequencing of Heterorhabditis nematodes to identify factors involved in symbiosis with Photorhabdus bacteria.

BMC genomics, 23(1):741.

BACKGROUND: Nematodes are a major group of soil inhabiting organisms. Heterorhabditis nematodes are insect-pathogenic nematodes and live in a close symbiotic association with Photorhabdus bacteria. Heterorhabditis-Photorhabdus pair offers a powerful and genetically tractable model to study animal-microbe symbiosis. It is possible to generate symbiont bacteria free (axenic) stages in Heterorhabditis. Here, we compared the transcriptome of symbiotic early-adult stage Heterorhabditis nematodes with axenic early-adult nematodes to determine the nematode genes and pathways involved in symbiosis with Photorhabdus bacteria.

RESULTS: A de-novo reference transcriptome assembly of 95.7 Mb was created for H. bacteriophora by using all the reads. The assembly contained 46,599 transcripts with N50 value of 2,681 bp and the average transcript length was 2,054 bp. The differentially expressed transcripts were identified by mapping reads from symbiotic and axenic nematodes to the reference assembly. A total of 754 differentially expressed transcripts were identified in symbiotic nematodes as compared to the axenic nematodes. The ribosomal pathway was identified as the most affected among the differentially expressed transcripts. Additionally, 12,151 transcripts were unique to symbiotic nematodes. Endocytosis, cAMP signalling and focal adhesion were the top three enriched pathways in symbiotic nematodes, while a large number of transcripts coding for various responses against bacteria, such as bacterial recognition, canonical immune signalling pathways, and antimicrobial effectors could also be identified.

CONCLUSIONS: The symbiotic Heterorhabditis nematodes respond to the presence of symbiotic bacteria by expressing various transcripts involved in a multi-layered immune response which might represent non-systemic and evolved localized responses to maintain mutualistic bacteria at non-threatening levels. Subject to further functional validation of the identified transcripts, our findings suggest that Heterorhabditis nematode immune system plays a critical role in maintenance of symbiosis with Photorhabdus bacteria.

RevDate: 2022-11-07

Bringhurst B, Allert M, Greenwold M, et al (2022)

Environments and Hosts Structure the Bacterial Microbiomes of Fungus-Gardening Ants and their Symbiotic Fungus Gardens.

Microbial ecology [Epub ahead of print].

The fungus gardening-ant system is considered a complex, multi-tiered symbiosis, as it is composed of ants, their fungus, and microorganisms associated with either ants or fungus. We examine the bacterial microbiome of Trachymyrmex septentrionalis and Mycetomoellerius turrifex ants and their symbiotic fungus gardens, using 16S rRNA Illumina sequencing, over a region spanning approximately 350 km (east and central Texas). Typically, microorganisms can be acquired from a parent colony (vertical transmission) or from the environment (horizontal transmission). Because the symbiosis is characterized by co-dispersal of the ants and fungus, elements of both ant and fungus garden microbiome could be characterized by vertical transmission. The goals of this study were to explore how both the ant and fungus garden bacterial microbiome are acquired. The main findings were that different mechanisms appear to explain the structure the microbiomes of ants and their symbiotic fungus gardens. Ant associated microbiomes had a strong host ant signature, which could be indicative of vertical inheritance of the ant associated bacterial microbiome or an unknown mechanism of active uptake or screening. On the other hand, the bacterial microbiome of the fungus garden was more complex in that some bacterial taxa appear to be structured by the ant host species, whereas others by fungal lineage or the environment (geographic region). Thus bacteria in fungus gardens appear to be acquired both horizontally and vertically.

RevDate: 2022-11-07

Wang H, Gu K, Sun H, et al (2022)

Reconfirmation of the symbiosis on carbon emissions and air pollution: A spatial spillover perspective.

The Science of the total environment pii:S0048-9697(22)07006-1 [Epub ahead of print].

Many studies have confirmed the co-emission characteristics of air pollution and carbon emissions. However, studies on the evolution and synergistic factors of the symbiosis of air pollution and carbon emissions over long time scales from a spatial spillover perspective are rare. Here, we identify the spatial evolution and agglomeration characteristics of carbon emissions and air pollution symbiosis by applying local autocorrelation analysis and geographical concentration and by using the dynamic spatial autoregressive model for multiple synergistic factors at city levels during 2006-2019 in China. The results are: (1) The spatial agglomeration and symbiosis of carbon emission and air pollution are similar and show strong spatial locking, as well as path-dependent properties. (2) The spatial imbalance of carbon emission agglomeration and pollution agglomeration gradually improved over time; the concentration centers are all located in Henan province, shifting northward. (3) The symbiosis between both carbon emission agglomeration and pollution agglomeration has significant "spatial and temporal scale effects", and the economic growth is nonlinear. Additionally, innovation vitality has a negative synergistic driving effect on this relationship. In addition to the results above, rapid industrialization and urbanization are taking place in China. Hence, serious actions against greenhouse gases and air pollutants are imminently needed.

RevDate: 2022-11-07

Fidopiastis PM, Childs C, Esin JJ, et al (2022)

Vibrio fischeri Possesses Xds and Dns Nucleases That Differentially Influence Phosphate Scavenging, Aggregation, Competence, and Symbiotic Colonization of Squid.

Applied and environmental microbiology [Epub ahead of print].

Cells of Vibrio fischeri colonize the light organ of Euprymna scolopes, providing the squid bioluminescence in exchange for nutrients and protection. The bacteria encounter DNA-rich mucus throughout their transition to a symbiotic lifestyle, leading us to hypothesize a role for nuclease activity in the colonization process. In support of this, we detected abundant extracellular nuclease activity in growing cells of V. fischeri. To discover the gene(s) responsible for this activity, we screened a V. fischeri transposon mutant library for nuclease-deficient strains. Interestingly, only one strain, whose transposon insertion mapped to nuclease gene VF_1451, showed complete loss of nuclease activity in our screens. A database search revealed that VF_1451 is homologous to the nuclease-encoding gene xds in Vibrio cholerae. However, V. fischeri strains lacking xds eventually revealed slight nuclease activity on plates after 72 h. This led us to hypothesize that a second secreted nuclease, identified through a database search as VF_0437, a homolog of V. cholerae dns, might be responsible for the residual nuclease activity. Here, we show that Xds and/or Dns are involved in essential aspects of V. fischeri biology, including natural transformation, aggregation, and phosphate scavenging. Furthermore, strains lacking either nuclease were outcompeted by the wild type for squid colonization. Understanding the specific role of nuclease activity in the squid colonization process represents an intriguing area of future research. IMPORTANCE From soil and water to host-associated secretions such as mucus, environments that bacteria inhabit are awash in DNA. Extracellular DNA (eDNA) is a nutritious resource that microbes dedicate significant energy to exploit. Calcium binds eDNA to promote cell-cell aggregation and horizontal gene transfer. eDNA hydrolysis impacts construction of and dispersal from biofilms. Strategies in which pathogens use nucleases to avoid phagocytosis or disseminate by degrading host secretions are well documented; significantly less is known about nucleases in mutualistic associations. This study describes the role of nucleases in the mutualism between V. fischeri and its squid host, Euprymna scolopes. We find that nuclease activity is an important determinant of colonization in V. fischeri, broadening our understanding of how microbes establish and maintain beneficial associations.

RevDate: 2022-11-07

Chandrasekar AP, AD Badley (2022)

Prime, shock and kill: BCL-2 inhibition for HIV cure.

Frontiers in immunology, 13:1033609.

While modern HIV therapy can effectively suppress viral replication, the persistence of the latent reservoir posits the greatest hurdle to complete cure. The "shock and kill" strategy is under investigation for HIV therapy, aiming to reactivate latent HIV, and subsequently eliminate it through anti-retroviral therapy and host immune function. However, thus far, studies have yielded suboptimal results, stemming from a combination of ineffective latency reversal and poor immune clearance. Concomitantly, studies have now revealed the importance of the BCL-2 anti-apoptotic protein as a critical mediator of infected cell survival, reservoir maintenance and immune evasion in HIV. Furthermore, BCL-2 inhibitors are now recognized for their anti-HIV effects in pre-clinical studies. This minireview aims to examine the intersection of BCL-2 inhibition and current shock and kill efforts, hoping to inform future studies which may ultimately yield a cure for HIV.

RevDate: 2022-11-07

Soto MJ, Staehelin C, Gourion B, et al (2022)

Editorial: Early signaling in the rhizobium-legume symbiosis.

Frontiers in plant science, 13:1056830.

RevDate: 2022-11-07

Wang A, Lv J, Wang J, et al (2022)

CO2 enrichment in greenhouse production: Towards a sustainable approach.

Frontiers in plant science, 13:1029901.

As the unique source of carbon in the atmosphere, carbon dioxide (CO2) exerts a strong impact on crop yield and quality. However, CO2 deficiency in greenhouses during the daytime often limits crop productivity. Crucially, climate warming, caused by increased atmospheric CO2, urges global efforts to implement carbon reduction and neutrality, which also bring challenges to current CO2 enrichment systems applied in greenhouses. Thus, there is a timely need to develop cost-effective and environmentally friendly CO2 enrichment technologies as a sustainable approach to promoting agricultural production and alleviating environmental burdens simultaneously. Here we review several common technologies of CO2 enrichment in greenhouse production, and their characteristics and limitations. Some control strategies of CO2 enrichment in distribution, period, and concentration are also discussed. We further introduce promising directions for future CO2 enrichment including 1) agro-industrial symbiosis system (AIS); 2) interdisciplinary application of carbon capture and utilization (CCU); and 3) optimization of CO2 assimilation in C3 crops via biotechnologies. This review aims to provide perspectives on efficient CO2 utilization in greenhouse production.

RevDate: 2022-11-07

Bukharin OV, Andryushchenko SV, Perunova NB, et al (2022)

Environmental Determination of Indigenous Bifidobacteria of the Human Intestine.

Herald of the Russian Academy of Sciences, 92(5):629-635.

The environmental determination of indigenous (constantly present) bifidobacteria of the human large intestine is considered in this review. Environmental determination (from the Latin determinere, "I determine") is understood as a set of natural phenomena of a habitat (biotope) that determine the role of indigenous microorganisms in the microbiocenosis. Using the symbiotic approach, an attempt is made to identify the environmental conditions for the habitat of bifidobacteria and their physiological effects in the microsymbiocenosis. The features of indigenous bifidobacteria in terms of their nature have been established: evolutionary-genetic (phylogenetic remoteness, genome conservation, metabolic specialization), biochemical (lysozyme resistance, constitutive acetate production), and physiological (microbial "friend-foe" identification, immunoregulation), which are important in adaptation (persistence) and the provision of mutualistic effects and stability of the bifidoflora in the population.

RevDate: 2022-11-07

Gundlach KA, Nawroth J, Kanso E, et al (2022)

Ciliated epithelia are key elements in the recruitment of bacterial partners in the squid-vibrio symbiosis.

Frontiers in cell and developmental biology, 10:974213 pii:974213.

The Hawaiian bobtail squid, Euprymna scolopes, harvests its luminous symbiont, Vibrio fischeri, from the surrounding seawater within hours of hatching. During embryogenesis, the host animal develops a nascent light organ with ciliated fields on each lateral surface. We hypothesized that these fields function to increase the efficiency of symbiont colonization of host tissues. Within minutes of hatching from the egg, the host's ciliated fields shed copious amounts of mucus in a non-specific response to bacterial surface molecules, specifically peptidoglycan (PGN), from the bacterioplankton in the surrounding seawater. Experimental manipulation of the system provided evidence that nitric oxide in the mucus drives an increase in ciliary beat frequency (CBF), and exposure to even small numbers of V. fischeri cells for short periods resulted in an additional increase in CBF. These results indicate that the light-organ ciliated fields respond specifically, sensitively, and rapidly, to the presence of nonspecific PGN as well as symbiont cells in the ambient seawater. Notably, the study provides the first evidence that this induction of an increase in CBF occurs as part of a thus far undiscovered initial phase in colonization of the squid host by its symbiont, i.e., host recognition of V. fischeri cues in the environment within minutes. Using a biophysics-based mathematical analysis, we showed that this rapid induction of increased CBF, while accelerating bacterial advection, is unlikely to be signaled by V. fischeri cells interacting directly with the organ surface. These overall changes in CBF were shown to significantly impact the efficiency of V. fischeri colonization of the host organ. Further, once V. fischeri has fully colonized the host tissues, i.e., about 12-24 h after initial host-symbiont interactions, the symbionts drove an attenuation of mucus shedding from the ciliated fields, concomitant with an attenuation of the CBF. Taken together, these findings offer a window into the very first interactions of ciliated surfaces with their coevolved microbial partners.

RevDate: 2022-11-07

Gonzalez OA, Wallet SM, RJ Lamont (2022)

Editorial: The role of epithelial cell-microbe interactions in oral health and disease.

Frontiers in oral health, 3:1044369.

RevDate: 2022-11-07

Wang Q, Dong A, Zhao J, et al (2022)

Vaginal microbiota networks as a mechanistic predictor of aerobic vaginitis.

Frontiers in microbiology, 13:998813.

Aerobic vaginitis (AV) is a complex vaginal dysbiosis that is thought to be caused by the micro-ecological change of the vaginal microbiota. While most studies have focused on how changes in the abundance of individual microbes are associated with the emergence of AV, we still do not have a complete mechanistic atlas of the microbe-AV link. Network modeling is central to understanding the structure and function of any microbial community assembly. By encapsulating the abundance of microbes as nodes and ecological interactions among microbes as edges, microbial networks can reveal how each microbe functions and how one microbe cooperate or compete with other microbes to mediate the dynamics of microbial communities. However, existing approaches can only estimate either the strength of microbe-microbe link or the direction of this link, failing to capture full topological characteristics of a network, especially from high-dimensional microbial data. We combine allometry scaling law and evolutionary game theory to derive a functional graph theory that can characterize bidirectional, signed, and weighted interaction networks from any data domain. We apply our theory to characterize the causal interdependence between microbial interactions and AV. From functional networks arising from different functional modules, we find that, as the only favorable genus from Firmicutes among all identified genera, the role of Lactobacillus in maintaining vaginal microbial symbiosis is enabled by upregulation from other microbes, rather than through any intrinsic capacity. Among Lactobacillus species, the proportion of L. crispatus to L. iners is positively associated with more healthy acid vaginal ecosystems. In a less healthy alkaline ecosystem, L. crispatus establishes a contradictory relationship with other microbes, leading to population decrease relative to L. iners. We identify topological changes of vaginal microbiota networks when the menstrual cycle of women changes from the follicular to luteal phases. Our network tool provides a mechanistic approach to disentangle the internal workings of the microbiota assembly and predict its causal relationships with human diseases including AV.

RevDate: 2022-11-07

Xu L, Niu X, Li X, et al (2022)

Effects of nitrogen addition and root fungal inoculation on the seedling growth and rhizosphere soil microbial community of Pinus tabulaeformis.

Frontiers in microbiology, 13:1013023.

Nitrogen (N) availability is significant in different ecosystems, but the response of forest plant-microbial symbionts to global N deposition remains largely unexplored. In this study, the effects of different N concentration levels on four types of fungi, Suillus granulatus (Sg), Pisolithus tinctorius (Pt), Pleotrichocladium opacum (Po), and Pseudopyrenochaeta sp. (Ps), isolated from the roots of Pinus tabulaeformis were investigated in vitro. Then, the effects of the fungi on the growth performance, nutrient uptake, and rhizosphere soil microbial community structure of P. tabulaeformis under different N addition conditions (0, 40, and 80 kg hm-2 year-1) were examined. The biomass and phytohormone contents of the Sg, Pt and Po strains increased with increasing N concentration, while those of the Ps strain first increased and then decreased. All four fungal strains could effectively colonize the plant roots and form a strain-dependent symbiosis with P. tabulaeformis. Although the effects depended on the fungal species, the growth and root development of inoculated seedlings were higher than those of uninoculated seedlings under N deficiency and normal N supply conditions. However, these positive effects disappeared and even became negative under high N supply conditions. The inoculation of the four fungal strains also showed significant positive effects on the shoot and root nutrient contents of P. tabulaeformis. Fungal inoculation significantly increased different microbial groups and the total soil microorganisms but decreased the microbial diversity under N deficiency stress. In summary, exogenous symbiotic fungal inoculations could increase the growth performance of P. tabulaeformis under N deficiency and normal N supply conditions, but the effects were negative under excessive N addition.

RevDate: 2022-11-07

Meyer KM, Deines P, Wei Z, et al (2022)

Editorial: The role of dispersal and transmission in structuring microbial communities.

Frontiers in microbiology, 13:1054498.

RevDate: 2022-11-07

Akimbekov NS, Digel I, Yerezhepov AY, et al (2022)

Nutritional factors influencing microbiota-mediated colonization resistance of the oral cavity: A literature review.

Frontiers in nutrition, 9:1029324.

The oral cavity is a key biocenosis for many distinct microbial communities that interact with both the external environment and internal body systems. The oral microbiota is a vital part of the human microbiome. It has been developed through mutual interactions among the environment, host physiological state, and microbial community composition. Indigenious microbiota of the oral cavity is one of the factors that prevent adhesion and invasion of pathogens on the mucous membrane, i.e., the development of the infectious process and thereby participating in the implementation of one of the mechanisms of local immunity-colonization resistance. The balance between bacterial symbiosis, microbial virulence, and host resistance ensures the integrity of the oral cavity. In this review we have tried to address how nutritional factors influence integrity of the oral indigenous microbiota and its involvement in colonization resistance.

RevDate: 2022-11-05

Ruman H, Y Kawaharada (2022)

A New Classification of Lysin Motif Receptor-like Kinases in Lotus Japonicus.

Plant & cell physiology pii:6806100 [Epub ahead of print].

Lysin motif receptor-like kinases (LysM-RLKs) are a plant-specific receptor protein family that sense components from soil microorganisms, regulating innate immunity and symbiosis. Every plant species possesses multiple LysM-RLKs in order to interact with a variety of soil microorganisms, however, most receptors have not been characterized yet. Therefore, we tried to identify LysM-RLKs from diverse plant species and proposed a new classification to indicate their evolution and characteristics, as well as to predict new functions. In this study, we have attempted to explore and update LysM-RLKs in Lotus japonicus using the latest genome sequencing and divided 20 LysM-RLKs into 11 clades based on homolog identity and phylogenetic analysis. We further identified 193 LysM-RLKs from 16 Spermatophyta species including L. japonicus and divided these receptors into 14 clades and one outgroup special receptor based on the classification of L. japonicus LysM-RLKs. All plant species not only have clade I receptors such as Nod factor or chitin receptors but also clade III receptors where most of the receptors are uncharacterized. We also identified dicotyledon- and monocotyledon-specific clades and predicted evolutionary trends in LysM-RLKs. In addition, we found a strong correlation between plant species that did not possess clade II receptors and those that lost symbiosis with arbuscular mycorrhizae fungi. A clade II receptor in Lotus japonicus Lys8 was predicted to express during arbuscular mycorrhizal symbiosis. Our proposed new inventory classification suggests the evolutionary pattern of LysM-RLKs and might help in elucidating novel receptor functions in various plant species.

RevDate: 2022-11-05

Waters MT, DC Nelson (2022)

Karrikin perception and signalling.

The New phytologist [Epub ahead of print].

Karrikins are a class of butenolide compounds found in smoke that were first identified as seed germination stimulants for fire-following species. Early studies of karrikins classified the germination and post-germination responses of many plant species, and investigated crosstalk with plant hormones that regulate germination. The discovery that Arabidopsis thaliana responds to karrikins laid the foundation for identifying mutants with altered karrikin responses. Genetic analysis of karrikin signalling revealed an unexpected link to strigolactones, a class of carotenoid-derived plant hormones. Substantial progress has since been made toward understanding how karrikins are perceived and regulate plant growth, in no small part due to advances in understanding strigolactone perception. Karrikin and strigolactone signalling systems are evolutionarily related and retain a high degree of similarity. There is strong evidence that karrikins (KARs) are natural analogues of an endogenous signal(s), KAI2 ligand (KL), which remains unknown. KAR/KL signalling regulates many developmental processes in plants including germination, seedling photomorphogenesis, and root and root hair growth. KAR/KL signalling also affects abiotic stress responses and arbuscular mycorrhizal symbiosis. Here we summarise the current knowledge of KAR/KL signalling, and discuss current controversies and unanswered questions in this field.

RevDate: 2022-11-05

Aubé J, Cambon-Bonavita MA, Velo-Suárez L, et al (2022)

A novel and dual digestive symbiosis scales up the nutrition and immune system of the holobiont Rimicaris exoculata.

Microbiome, 10(1):189.

BACKGROUND: In deep-sea hydrothermal vent areas, deprived of light, most animals rely on chemosynthetic symbionts for their nutrition. These symbionts may be located on their cuticle, inside modified organs, or in specialized cells. Nonetheless, many of these animals have an open and functional digestive tract. The vent shrimp Rimicaris exoculata is fueled mainly by its gill chamber symbionts, but also has a complete digestive system with symbionts. These are found in the shrimp foregut and midgut, but their roles remain unknown. We used genome-resolved metagenomics on separate foregut and midgut samples, taken from specimens living at three contrasted sites along the Mid-Atlantic Ridge (TAG, Rainbow, and Snake Pit) to reveal their genetic potential.

RESULTS: We reconstructed and studied 20 Metagenome-Assembled Genomes (MAGs), including novel lineages of Hepatoplasmataceae and Deferribacteres, abundant in the shrimp foregut and midgut, respectively. Although the former showed streamlined reduced genomes capable of using mostly broken-down complex molecules, Deferribacteres showed the ability to degrade complex polymers, synthesize vitamins, and encode numerous flagellar and chemotaxis genes for host-symbiont sensing. Both symbionts harbor a diverse set of immune system genes favoring holobiont defense. In addition, Deferribacteres were observed to particularly colonize the bacteria-free ectoperitrophic space, in direct contact with the host, elongating but not dividing despite possessing the complete genetic machinery necessary for this.

CONCLUSION: Overall, these data suggest that these digestive symbionts have key communication and defense roles, which contribute to the overall fitness of the Rimicaris holobiont. Video Abstract.

RevDate: 2022-11-04

Li Y, Yu H, Liu L, et al (2022)

Transcriptomic and physiological analyses unravel the effect and mechanism of halosulfuron-methyl on the symbiosis between rhizobium and soybean.

Ecotoxicology and environmental safety, 247:114248 pii:S0147-6513(22)01088-0 [Epub ahead of print].

Halosulfuron-methyl (HSM) is a new and highly effective sulfonylurea herbicide widely used in weed control, but its residue in the environment poses a potential risk to soybean. Soybean-rhizobium symbiotic nitrogen fixation is crucial for sustainable agricultural development and ecological environment health. However, the impact of HSM on the symbiosis between soybean and rhizobium is unclear. In this study, the effects of HSM on the soybean-rhizobium symbiotic process and nitrogen fixation were investigated by means of transcriptomic and physiological analyses. Treatment with a concentration of HSM less than 0.5 mg L-1 had no effect on rhizobium growth, but significantly reduced nodules number, the biomass of soybean nodules, and nitrogenase activity in root nodules (P < 0.05). Transcriptomic analysis showed that differentially expressed genes (DEGs) involved in NH4+ assimilation were significantly downregulated (P < 0.05). In addition, the activities of NH4+ assimilation enzymes were markedly reduced. This result was further confirmed by the accumulation of NH4+ in root nodules, indicating that the inhibition of nitrogen fixation by HSM may be caused by excessive NH4+ accumulation in root nodules. Furthermore, DEGs involved in flavonoid synthesis, phytohormone biosynthesis, and phytohormone signaling transduction were significantly downregulated (P < 0.05), which was consistent with the decrease in flavonoid and phytohormone contents determined in this study. These results suggested that HSM may inhibit soybean nodulation by inhibiting flavonoid synthesis in soybean roots, disrupting the balance of plant endogenous hormones in roots during symbiosis, and blocking the transmission of hormone signals during the symbiosis. Our findings provide new insights into the effects of HSM on the legume-rhizobium nodule symbiotic process.

RevDate: 2022-11-04

Agwunobi DO, Wang M, Wang Z, et al (2022)

The toxicity of the monoterpenes from lemongrass is mitigated by the detoxifying symbiosis of bacteria and fungi in the tick Haemaphysalis longicornis.

Ecotoxicology and environmental safety, 247:114261 pii:S0147-6513(22)01101-0 [Epub ahead of print].

The entry mode of terpenes into the atmosphere is via volatilization of hydrocarbons from foliage over heavily forested areas besides entering the environment through surface water runoff. Some monoterpenes in essential oils are phytotoxins, acting as plant chemical defenses against bacteria or fungi infections and plant-eating insects. For organisms to survive, their enzymatic systems are activated in response to an assault by potentially harmful compounds. Certain bacterial and fungal genera have developed special abilities to transform toxic terpenes into less toxic derivatives. Here, we investigated the response of the bacterial and fungal community in Haemaphysalis longicornis exposed to Cymbopogon citratus (lemongrass) essential oil (EO) and citronellal. Sequencing of bacterial 16S rRNA and fungal ITS1 regions on an Illumina NovaSeq PE250 sequencing platform was performed for H. longicornis tick samples treated with 15 and 20 mg/mL of lemongrass essential oil and citronellal. The diversity recorded in samples treated with C. citratus EO was higher in comparison to those treated with citronellal but significantly lower in the control samples as reflected by the Shannon diversity index. All major H. longicornis bacterial phyla, including Proteobacteria (93.81 %), Firmicutes (2.58 %), and Bacteroidota (0.99 %) were detected. A switch of dominance from Coxiella to Pseudomonas, which has high biotransformation capacity, was observed in the bacterial community, whereas the phylum Ascomycota (Genera: Aspergillus, Archaeorhizomyces, Alternaria, and Candida) dominated in the fungal community indicating detoxifying symbiosis. Other significantly abundant bacterial genera include Ralstonia, Acinetobacter, Vibrio, and Pseudoalteromonas, while Ganoderma and Trichosporon (yeasts) spp. represented the fungi Basidiomycota. This study expanded the understanding of enzymatic modification of phytotoxic substances by microorganisms, which could provide deeper insights into the mitigation of harmful phytotoxins and the synthesis of eco-friendly derivatives for the control of ticks.

RevDate: 2022-11-04

Ranjan N, Singh PK, NS Maurya (2022)

Pharmaceuticals in water as emerging pollutants for river health: A critical review under Indian conditions.

Ecotoxicology and environmental safety, 247:114220 pii:S0147-6513(22)01060-0 [Epub ahead of print].

The wastewaters from pharmaceutical manufacturing units, hospitals, and domestic sewage contaminated with excretal matters of medicine users are the prime sources of pharmaceutical pollutants (PPs) in natural water bodies. In the present study, PPs have been considered one of the emerging pollutants (EPs) and a cause of concern in river health assessment. Beyond the reported increase in antibiotic-resistant bacteria (ABRB), PPs have been found adversely affecting the biotic diversity in such water environments. Considering Algae, Macroinvertebrates, and Fishes as three distinct trophic level indicators, the present study puts forward a framework for showing River Health Condition (RHC) based on the calculation of a River Health Index (RHI). The RHI is calculated using six Indicator Group Scores (IGS) which individually reflect river health in a defined category of water quality characteristics. While Dissolved Oxygen Related Parameters (DORP), Nutrients (NT), and PPs are taken as causative agents affecting RHCs, scores of Algal-Bacterial (AB) symbiosis, Macroinvertebrates (MI), and Fishes (F) are considered as an effect of such environmental conditions. Current wastewater treatment technologies are also not very effective in the removal of PPs. The objective of the present study is to review the harmful effects of PPs on the aquatic environment, particularly on the chemical and biotic indicators of river health. Based on predicted no-effect concentrations (PNEC) for algae, macroinvertebrates, and fishes in the aquatic environment and measured environmental concentration (MEC) in the river, the estimated risk quotient (RQ) for norfloxacin in the Isakavagu-Nakkavagu stream of river Godavari, Hyderabad is found 293 for algae, 39 for MI, and 335 for fish. Among PPs, in Indian rivers, the presence of caffeine is the most frequent, with algae at the highest level of risk (RQmax= 24.5). Broadly six PPs, including azithromycin, caffeine, diclofenac, naproxen, norfloxacin, and sulfamethoxazole are found above PNEC values in Indian rivers. The application of IGS and RHI in understanding and presenting the river health condition (RHC) through colored hexagons has been demonstrated for the river Ganga near Varanasi (India) as an example. Identification of critical indicator groups, based on IGS provides a scientific basis for planned intervention for river health restoration to achieve an acceptable category.

RevDate: 2022-11-04

Uchiumi Y, Sato M, A Sasaki (2022)

Evolutionary double suicide in symbiotic systems.

Mutualism is thought to face a threat of coextinction cascade because the loss of a member species could lead to the extinction of the other member. Despite this common emphasis on the perils of such knock-on effect, hitherto, the evolutionary causes leading to extinction have been less emphasised. Here, we examine how extinction could be triggered in mutualism and whether an evolutionary response to partner loss could prevent collateral extinctions, by theoretically examining the coevolution of the host exploitation by symbionts and host dependence on symbiosis. Our model reveals that mutualism is more vulnerable to co-extinction through adaptive evolution (evolutionary double suicide) than parasitism. Additionally, it shows that the risk of evolutionary double suicide rarely promotes the backward evolution to an autonomous (non-symbiotic) state. Our results provide a new perspective on the evolutionary fragility of mutualism and the rarity of observed evolutionary transitions from mutualism to parasitism.

RevDate: 2022-11-04

Beekman MM, Donner SH, Litjens JJH, et al (2022)

Do aphids in Dutch sweet pepper greenhouses carry heritable elements that protect them against biocontrol parasitoids?.

Evolutionary applications, 15(10):1580-1593 pii:EVA13347.

Biological control (biocontrol) of crop pests is a sustainable alternative to the use of biodiversity and organismal health-harming chemical pesticides. Aphids can be biologically controlled with parasitoid wasps; however, variable results of parasitoid-based aphid biocontrol in greenhouses are reported. Aphids may display genetically encoded (endogenous) defences that increase aphid resistance against parasitoids as under high parasitoid pressure there will be selection for parasitoid-resistant aphids, potentially affecting the success of parasitoid-based aphid biocontrol in greenhouses. Additionally, aphids may carry secondary bacterial endosymbionts that protect them against parasitoids. We studied whether there is variation in either of these heritable elements in aphids in greenhouses of sweet pepper, an agro-economically important crop in the Netherlands that is prone to aphid pests and where pest management heavily relies on biocontrol. We sampled aphid populations in organic (biocontrol only) and conventional (biocontrol and pesticides) sweet pepper greenhouses in the Netherlands during the 2019 crop growth season. We assessed the aphid microbiome through both diagnostic PCR and 16S rRNA sequencing and did not detect any secondary endosymbionts in the two most encountered aphid species, Myzus persicae and Aulacorthum solani. We also compared multiple aphid lines collected from different greenhouses for variation in levels of endogenous-based resistance against the parasitoids commonly used as biocontrol agents. We found no differences in the levels of endogenous-based resistance between different aphid lines. This study does not support the hypothesis that protective endosymbionts or the presence of endogenous resistant aphid lines affects the success of parasitoid-based biocontrol of aphids in Dutch greenhouses. Future investigations will need to address what is causing the variable successes of aphid biocontrol and what (biological and management-related) lessons can be learned for aphid control in other crops, and biocontrol in general.

RevDate: 2022-11-04

Denison RF, KE Muller (2022)

An evolutionary perspective on increasing net benefits to crops from symbiotic microbes.

Evolutionary applications, 15(10):1490-1504 pii:EVA13384.

Plant-imposed, fitness-reducing sanctions against less-beneficial symbionts have been documented for rhizobia, mycorrhizal fungi, and fig wasps. Although most of our examples are for rhizobia, we argue that the evolutionary persistence of mutualism in any symbiosis would require such sanctions, if there are multiple symbiont genotypes per host plant. We therefore discuss methods that could be used to develop and assess crops with stricter sanctions. These include methods to screen strains for greater mutualism as resources to identify crop genotypes that impose stronger selection for mutualism. Single-strain experiments that measure costs as well as benefits have shown that diversion of resources by rhizobia can reduce nitrogen-fixation efficiency (N per C) and that some legumes can increase this efficiency by manipulating their symbionts. Plants in the field always host multiple strains with possible synergistic interactions, so benefits from different strains might best be compared by regressing plant growth or yield on each strain's abundance in a mixture. However, results from this approach have not yet been published. To measure legacy effects of stronger sanctions on future crops, single-genotype test crops could be planted in a field that recently had replicated plots with different genotypes of the sanction-imposing crop. Enhancing agricultural benefits from symbiosis may require accepting tradeoffs that constrained past natural selection, including tradeoffs between current and future benefits.

RevDate: 2022-11-04

Yin L, Wei M, Wu G, et al (2022)

Epichloë endophytes improved Leymus chinensis tolerance to both neutral and alkali salt stresses.

Frontiers in plant science, 13:968774.

Symbiotic relationships with microbes may influence how plants respond to environmental change. In the present study, we tested the hypothesis that symbiosis with the endophytes promoted salt tolerance of the native grass. In the field pot experiment we compared the performance of endophyte-infected (E+) and endophyte-uninfected (E-) Leymus chinensis, a dominant species native to the Inner Mongolia steppe, under altered neutral and alkaline salt stresses. The results showed that under both neutral and alkaline salt stresses, endophyte infection significantly increased plant height, leaf length and fibrous root biomass. Under neutral salt stress, endophyte infection decreased Na+ content and Na+/K+ ratio (p=0.066) in the leaf sheath while increased Ca2+ and Mg2+ content in the rhizome. Under alkali salt stress, endophyte infection tended to increase K+ content in the fibrous root, enhance Mg2+ content in the fibrous root while reduce Na+/K+ ratio in the leaf blade in the 100 mmol/L alkali salt treatment. Although endophyte-infected L. chinensis cannot accumulate Na+ high enough to be halophytes, the observed growth promotion and stress tolerance give endophyte/plant associations the potential to be a model for endophyte-assisted phytoremediation of saline-alkaline soils.

RevDate: 2022-11-03

Joglekar A, Nimonkar Y, Bajaj A, et al (2022)

Resolution of inter/intraspecies variation in Weissella group requires multigene analysis and functional characterization.

Journal of basic microbiology [Epub ahead of print].

Weissella confusa and Weissella cibaria strains isolated from the human- gut are considered as potential probiotics, but remain under-explored owing to their ambiguous taxonomic assignment. The present study assesses the taxonomic resolution of 11 strains belonging to W. confusa and W. cibaria species and highlights the inter- and intraspecies variations using an array of phenetic and molecular methods. Remarkable genomic variability among the strains was observed by phylogenetic analysis using concatenated housekeeping genes (pheS, gyrB, and dnaA) along with 16S rRNA gene sequence, suggesting intraspecies variations; which is also supported by the phenetic data. Analysis showed that 16S rRNA gene sequence alone could not resolve the variation, and among the tested marker genes, signals from pheS gene provide better taxonomic resolution. The biochemical and antibiotic susceptibility tests also showed considerable variations among the isolates. Additionally, 'quick' identification using mass spectroscopy-based matrix-assisted laser desorption/ionization-time of flight mass spectra was accurate up to genus only, and not species level, for the Weissella group. The study highlights need for inclusion of functional, phenetic, and multigene phylogenetic analysis in addition to 16S rRNA gene-based identification for the Weissella group, to provide better resolution in taxonomic assignments, which is often a prerequisite for the selection of potential strains with biotechnological applications.

RevDate: 2022-11-04
CmpDate: 2022-11-04

Viladrich N, Linares C, JL Padilla-Gamiño (2022)

Lethal and sublethal effects of thermal stress on octocorals early life-history stages.

Global change biology, 28(23):7049-7062.

The frequency and severity of marine heatwaves causing mass mortality events in tropical and temperate coral species increases every year, with serious consequences on the stability and resilience of coral populations. Although recovery and persistence of coral populations after stress events is closely related to adult fitness, as well as larval survival and settlement, much remains unknown about the effects of thermal stress on early life-history stages of temperate coral species. In the present study, the reproductive phenology and the effect of increased water temperature (+4°C and +6°C above ambient, 20°C) on larval survival and settlement was evaluated for two of the most representative Mediterranean octocoral species (Eunicella singularis and Corallium rubrum). Our study shows that reproductive behavior is more variable than previously reported and breeding period occurs over a longer period in both species. Thermal stress did not affect the survival of symbiotic E. singularis larvae but drastically reduced the survival of the non-symbiotic C. rubrum larvae. Results on larval biomass and caloric consumption suggest that higher mortality rates of C. rubrum exposed to increased temperature were not related to depletion of endogenous energy in larvae. The results also show that settlement rates of E. singularis did not change in response to elevated temperature after 20 days of exposure, but larvae may settle fast and close to their native population at 26°C (+6°C). Although previous experimental studies found that adult colonies of both octocoral species are mostly resistant to thermal stress, our results on early life-history stages suggest that the persistence and inter-connectivity of local populations may be severely compromised under continued trends in ocean warming.

RevDate: 2022-11-04
CmpDate: 2022-11-04

Eck JL, Kytöviita MM, AL Laine (2022)

Arbuscular mycorrhizal fungi influence host infection during epidemics in a wild plant pathosystem.

The New phytologist, 236(5):1922-1935.

While pathogenic and mutualistic microbes are ubiquitous across ecosystems and often co-occur within hosts, how they interact to determine patterns of disease in genetically diverse wild populations is unknown. To test whether microbial mutualists provide protection against pathogens, and whether this varies among host genotypes, we conducted a field experiment in three naturally occurring epidemics of a fungal pathogen, Podosphaera plantaginis, infecting a host plant, Plantago lanceolata, in the Åland Islands, Finland. In each population, we collected epidemiological data on experimental plants from six allopatric populations that had been inoculated with a mixture of mutualistic arbuscular mycorrhizal fungi or a nonmycorrhizal control. Inoculation with arbuscular mycorrhizal fungi increased growth in plants from every population, but also increased host infection rate. Mycorrhizal effects on disease severity varied among host genotypes and strengthened over time during the epidemic. Host genotypes that were more susceptible to the pathogen received stronger protective effects from inoculation. Our results show that arbuscular mycorrhizal fungi introduce both benefits and risks to host plants, and shift patterns of infection in host populations under pathogen attack. Understanding how mutualists alter host susceptibility to disease will be important for predicting infection outcomes in ecological communities and in agriculture.

RevDate: 2022-11-04
CmpDate: 2022-11-04

Roik A, Reverter M, C Pogoreutz (2022)

A roadmap to understanding diversity and function of coral reef-associated fungi.

FEMS microbiology reviews, 46(6):.

Tropical coral reefs are hotspots of marine productivity, owing to the association of reef-building corals with endosymbiotic algae and metabolically diverse bacterial communities. However, the functional importance of fungi, well-known for their contribution to shaping terrestrial ecosystems and global nutrient cycles, remains underexplored on coral reefs. We here conceptualize how fungal functional traits may have facilitated the spread, diversification, and ecological adaptation of marine fungi on coral reefs. We propose that functions of reef-associated fungi may be diverse and go beyond their hitherto described roles of pathogens and bioeroders, including but not limited to reef-scale biogeochemical cycles and the structuring of coral-associated and environmental microbiomes via chemical mediation. Recent technological and conceptual advances will allow the elucidation of the physiological, ecological, and chemical contributions of understudied marine fungi to coral holobiont and reef ecosystem functioning and health and may help provide an outlook for reef management actions.

RevDate: 2022-11-03

Cao ZZ, Bao YY, Chen Z, et al (2022)

Fibroblast-epithelial metabolic coupling in laryngeal cancer.

Pathology, research and practice, 240:154177 pii:S0344-0338(22)00421-6 [Epub ahead of print].

OBJECTIVES: To explore the Fibroblast-epithelial metabolic coupling among laryngeal cancers and its prognostic roles METHODS: We reviewed the clinical information of patients with laryngeal cancer in our department. Paraffin-embedded tissues from included patients were immune-stained with antibodies towards MCT4 and TOMM20 and evaluated for stromal and epithelial expression. Survival analysis and Cox regression analysis were applied to investigate the prognostic factor of laryngeal squamous cell carcinoma. TCGA database was used to validate our result.

RESULTS: Stromal MCT4 and TOMM20 were both significantly associated with each other among laryngeal cancer tissues. High expression of both Stromal MCT4 and TOMM20 is related to poor prognosis in laryngeal cancer. Stromal MCT4 expression was an independent prognostic indicator for laryngeal cancer. Furthermore, cancer cell MCT4 expression has no relationship with the clinical characteristics of laryngeal cancer.

CONCLUSIONS: Our results support that the phenomenon of metabolic symbiosis was exist in the laryngeal cancer tissue. In addition, TOMM20 and stromal MCT4 could be used as new therapeutic targets for laryngeal cancer.

RevDate: 2022-11-03

Matsushita S, Nagasawa M, T Kikusui (2022)

Autonomic nervous system responses of dogs to human-dog interaction videos.

PloS one, 17(11):e0257788 pii:PONE-D-21-29226.

We examined whether dogs show emotional response to social stimuli played on videos. Secondary, we hypothesized that if dogs recognize themselves in videos, they will show a different emotional response to videos of self and other dogs. We compared heart rate variability among four video stimuli: a video of the owner ignoring another dog (OW-A-IGN), a video of a non-owner interacting with another dog (NOW-A-INT), a video of the owner interacting with another dog (OW-A-INT), and a video of the owner interacting with the dog subject (OW-S-INT). The results showed that root mean square of the difference between adjacent R-R Intervals (RMSSD) and standard deviation of the R-R Interval (SDNN) were lower in NOW-A-INT and OW-S-INT than in OW-A-IGN. There was no statistical difference in the responses to OW-S-INT and OW-A-INT, suggesting that dogs did not distinguish themselves and other dogs in videos. On the other hand, the difference in mean R-R Interval between OW-S-INT and OW-A-INT showed positive correlation with the score of attachment or attention-seeking behavior. Therefore, this study does not completely rule out self-recognition in dogs and there remains the possibility that the more attached a dog to its owner, the more distinct the dog's emotional response to the difference between the self-video stimulus and the video stimulus of another dog. Further studies are needed to clarify this possibility.

RevDate: 2022-11-03

Sun Y, Wang M, Chen H, et al (2022)

Insights into symbiotic interactions from metatranscriptome analysis of deep-sea mussel Gigantidas platifrons under long-term laboratory maintenance.

Molecular ecology [Epub ahead of print].

Symbioses between invertebrates and chemosynthetic bacteria are of fundamental importance in deep-sea ecosystems, but the mechanisms that enable their symbiont associations are still largely undescribed, owing to the culturable difficulties of deep-sea lives. Bathymodiolinae mussels are remarkable in their ability to overcome decompression and can be maintained successfully for an extended period under atmospheric pressure, thus providing a model for investigating the molecular basis of symbiotic interactions. Herein, we conducted metatranscriptome sequencing and gene co-expression network analysis of Gigantidas platifrons under laboratory maintenance with gradual loss of symbionts. The results revealed that one-day short-term maintenance triggered global transcriptional perturbation in symbionts, but little gene expression changes in mussel hosts, which were mainly involved in responses to environmental changes. Long-term maintenance with depleted symbionts induced a metabolic shift in the mussel host. The most notable changes were the suppression of sterol biosynthesis and the complementary activation of terpenoid backbone synthesis in response to the reduction of bacteria-derived terpenoid sources. In addition, we detected the upregulation of host proteasomes responsible for amino acid deprivation caused by symbiont depletion. Additionally, a significant correlation between host microtubule motor activity and symbiont abundance was revealed, suggesting the possible function of microtubule-based intracellular trafficking in the nutritional interaction of symbiosis. Overall, by analyzing the dynamic transcriptomic changes during the loss of symbionts, our study highlights the nutritional importance of symbionts in supplementing terpenoid compounds and essential amino acids and provides insight into the molecular mechanisms and strategies underlying the symbiotic interactions in deep-sea ecosystems.

RevDate: 2022-11-03

Gueddou A, Sbissi I, Louati M, et al (2022)

Root Nodule Microsymbionts of Native Coriaria myrtifolia in Algeria.

Microbiology insights, 15:11786361221133794 pii:10.1177_11786361221133794.

Coriaria myrtifolia occurs as natural flora of warm temperate climates of northern Algeria which commonly found in hedges, forest and ravine edges. This actinorhizal species was known to establish a mutualistic symbiosis with members of phylogenetic cluster 2 (including strains associated to Coriaria spp., Ceanothus, Datiscaceae, and Dryadoideae) within the genus Frankia. Attempts to isolate C. myrtifolia microsymbionts from native plants growing in 4 locations in Algeria permitted to only recover asymbiotic Frankia strains (unable to reestablish nodulation and to fix nitrogen) from phylogenetic cluster 4 and several non-Frankia actinobacteria including members of Micrococcus, Micromonospora, Nocardia, Plantactinospora, and Streptomyces genera. The biodiversity of Frankia microsymbionts of C. myrtifolia root nodules was assessed using PCR-amplification followed by partial nucleotide sequencing of glnA1 (glutamine synthetase type 1) gene. On the 12 different glnA1 gene sequences obtained in this study, 9 were detected for the first time, and were mainly closelyrelated to Mediterranean genotypes previously described in the Grand Maghreb countries (Morocco and Tunisia) and in Europe (France) but without clear separations from other cluster 2 genotypes.

RevDate: 2022-11-03

Gonçalves GRL, Wolf MR, Antunes M, et al (2022)

Ontogenetic niche specialization of the spider crab Libinia ferreirae associated with the medusa Lychnorhiza lucerna.

Current zoology, 68(5):549-559 pii:zoab095.

Symbiotic relationships in marine environments are not fixed and can change throughout the animal's life. This study investigated the ontogeny of symbiosis of the spider crab Libinia ferreirae with the host medusa Lychnorhiza lucerna. We described the type of relationship, the temporal correlation among species, and food habits. More than 50% of the sampled crabs were symbionts, most in early life stages. The highest number of crabs found in a single medusa was 11. Symbiosis was observed throughout most of the year but was more evident in warm periods. The crab has many benefits in this relationship with a medusa. One is the use of food resources captured by the medusa, primarily copepods. Because the crab steals the medusa's food, it is a kleptoparasitic relationship. There is a niche partition between symbiont and the free-living crabs as they occupy different habitats and use nonoverlapping food resources. Previous research reported that symbiosis first developed during the crab's last larval phase (megalopa) when crab and medusa are in the same habitat. Observation of the crab's behavior shows that symbiosis occurs when the crab can grab to the medusa when the host touches the sea bottom. The crab also took advantage of water currents, releasing itself from the substrate and then drifting toward the medusa. The symbiotic relationship that crabs have with the medusa provides then with a nursery, food resources, shelter, dispersion, and decreased competition with free-living adult crabs, all essential for the crab's survival.

RevDate: 2022-11-03
CmpDate: 2022-11-03

Hasik AZ, AM Siepielski (2022)

Parasitism shapes selection by drastically reducing host fitness and increasing host fitness variation.

Biology letters, 18(11):20220323.

Determining the effects of parasites on host reproduction is key to understanding how parasites affect the underpinnings of selection on hosts. Although infection is expected to be costly, reducing mean fitness, infection could also increase variation in fitness costs among hosts, both of which determine the potential for selection on hosts. To test these ideas, we used a phylogenetically informed meta-analysis of 118 studies to examine how changes in the mean and variance in the outcome of reproduction differed between parasitized and non-parasitized hosts. We found that parasites had severe negative effects on mean fitness, with parasitized hosts suffering reductions in fecundity, viability and mating success. Parasite infection also increased variance in reproduction, particularly fecundity and offspring viability. Surprisingly, parasites had similar effects on viability when either the male or female was parasitized. These results not only provide the first synthetic, comparative, and quantitative summary of the strong deleterious effects of parasites on host reproductive fitness, but also reveal a consistent role for parasites in shaping the opportunity for selection.

RevDate: 2022-11-03
CmpDate: 2022-11-03

Moffat JJ, Coffroth MA, Wallingford PD, et al (2022)

Symbiont genotype influences holobiont response to increased temperature.

Scientific reports, 12(1):18394.

As coral reefs face warming oceans and increased coral bleaching, a whitening of the coral due to loss of microalgal endosymbionts, the possibility of evolutionary rescue offers some hope for reef persistence. In tightly linked mutualisms, evolutionary rescue may occur through evolution of the host and/or endosymbionts. Many obligate mutualisms are composed of relatively small, fast-growing symbionts with greater potential to evolve on ecologically relevant time scales than their relatively large, slower growing hosts. Numerous jellyfish species harbor closely related endosymbiont taxa to other cnidarian species such as coral, and are commonly used as a model system for investigating cnidarian mutualisms. We examined the potential for adaptation of the upside-down jellyfish Cassiopea xamachana to increased temperature via evolution of its microalgal endosymbiont, Symbiodinium microadriaticum. We quantified trait variation among five algal genotypes in response to three temperatures (26 °C, 30 °C, and 32 °C) and fitness of hosts infected with each genotype. All genotypes showed positive growth rates at each temperature, but rates of respiration and photosynthesis decreased with increased temperature. Responses varied among genotypes but were unrelated to genetic similarity. The effect of temperature on asexual reproduction and the timing of development in the host also depended on the genotype of the symbiont. Natural selection could favor different algal genotypes at different temperatures, affecting host fitness. This eco-evolutionary interaction may be a critical component of understanding species resilience in increasingly stressful environments.

RevDate: 2022-11-03
CmpDate: 2022-11-03

Nakase Y, Fukumasu Y, Toji T, et al (2022)

Parasitism by multiple strepsipterans accelerates timing of adult parasite emergence.

Ecology, 103(11):e3811.

RevDate: 2022-11-02

Ito S, Braguy J, Wang JY, et al (2022)

Canonical strigolactones are not the major determinant of tillering but important rhizospheric signals in rice.

Science advances, 8(44):eadd1278.

Strigolactones (SLs) are a plant hormone inhibiting shoot branching/tillering and a rhizospheric, chemical signal that triggers seed germination of the noxious root parasitic plant Striga and mediates symbiosis with beneficial arbuscular mycorrhizal fungi. Identifying specific roles of canonical and noncanonical SLs, the two SL subfamilies, is important for developing Striga-resistant cereals and for engineering plant architecture. Here, we report that rice mutants lacking canonical SLs do not show the shoot phenotypes known for SL-deficient plants, exhibiting only a delay in establishing arbuscular mycorrhizal symbiosis, but release exudates with a significantly decreased Striga seed-germinating activity. Blocking the biosynthesis of canonical SLs by TIS108, a specific enzyme inhibitor, significantly lowered Striga infestation without affecting rice growth. These results indicate that canonical SLs are not the determinant of shoot architecture and pave the way for increasing crop resistance by gene editing or chemical treatment.

RevDate: 2022-11-02

Diehl JMC, Kowallik V, Keller A, et al (2022)

First experimental evidence for active farming in ambrosia beetles and strong heredity of garden microbiomes.

Proceedings. Biological sciences, 289(1986):20221458.

Fungal cultivation is a defining feature for advanced agriculture in fungus-farming ants and termites. In a third supposedly fungus-farming group, wood-colonizing ambrosia beetles, an experimental proof for the effectiveness of beetle activity for selective promotion of their food fungi over others is lacking and farming has only been assumed based on observations of social and hygienic behaviours. Here, we experimentally removed mothers and their offspring from young nests of the fruit-tree pinhole borer, Xyleborinus saxesenii. By amplicon sequencing of bacterial and fungal communities of nests with and without beetles we could show that beetles are indeed able to actively shift symbiont communities. Although being consumed, the Raffaelea food fungi were more abundant when beetles were present while a weed fungus (Chaetomium sp.) as well as overall bacterial diversity were reduced in comparison to nests without beetles. Core symbiont communities were generally of low diversity and there were strong signs for vertical transmission not only for the cultivars, but also for secondary symbionts. Our findings verify the existence of active farming, even though the exact mechanisms underlying the selective promotion and/or suppression of symbionts need further investigation.

RevDate: 2022-11-02

Cervantes-Pérez SA, Thibivilliers S, Laffont C, et al (2022)

Cell-specific pathways recruited for symbiotic nodulation in the Medicago truncatula legume.

Molecular plant pii:S1674-2052(22)00373-2 [Epub ahead of print].

Medicago truncatula is a model legume species that has been studied for decades to understand the symbiotic relationship between legumes and soil bacteria collectively named rhizobia. This symbiosis called nodulation is initiated in roots with the infection of root hair cells by the bacteria as well as the initiation of nodule primordia from root cortical, endodermal, and pericycle cells, leading to the development of a new root organ, the nodule, where bacteria fix and assimilate the atmospheric dinitrogen for the benefit of the plant. Here, we report the isolation and use of nuclei from mock and rhizobia-inoculated roots to conduct single nuclei RNA-seq (sNucRNA-seq) experiments to gain a deeper understanding of early responses to rhizobial infection in Medicago roots. A gene expression map of the Medicago root was generated, comprising 25 clusters, which were annotated as specific cell-types using 119 Medicago marker genes and orthologs to Arabidopsis cell-type marker genes. A focus on root hair, cortex, endodermis, and pericycle cell-types, showing the strongest differential regulations in response to a short-term (48 hours) rhizobium inoculation, revealed both known genes and functional pathways, validating the sNucRNA-seq approach, but also numerous novel genes and pathways, allowing a comprehensive analysis of early root symbiotic responses at a cell-type-specific level.

RevDate: 2022-11-02

Jadhav S, Behl O, Khurjekar A, et al (2022)

Google Classroom as a Teaching Tool for Undergraduate Embryology.

Cureus, 14(9):e29701.

Context and aim Modern teaching of medicine has evolved into a beyond-the-classroom experience. Learning management systems (LMSs) have made this possible because of easy accessibility and user-friendliness. The COVID-19 lockdown further accentuated the need for this mode of education delivery. General embryology (GE) is a subject under human anatomy that does not rely on "touch-and-feel" as much as other medical subjects. Assess Google Classroom (GC) as a teaching tool to deliver an online undergraduate-level general embryology (GE) course. Settings and design A cross-sectional study involving 211 undergraduate medical students across India. Methods and material A pre-and post-quiz model was adopted to evaluate the efficiency of a five-lecture course on GE. The course content was delivered via 20-minute YouTube video lectures, uploaded on GC. Lastly, student feedback regarding gadget preferences and the overall learning experience was collected. Statistical Analysis: The confidence interval was set at 95%, and a p-value

RevDate: 2022-11-01

Yang YM, Zhu Y, Naseer M, et al (2022)

Rhizosphere effect of nanoscale zero-valent iron on mycorrhiza-dependent maize assimilation.

Plant, cell & environment [Epub ahead of print].

Rhizosphere effect of nanoscale zero-valent iron (nZVI) is crucial but little reported. Maize seeds were dressed with four nZVI concentrations (0, 1.0, 1.5, 2 g·kg-1) and inoculated with arbuscular mycorrhizal fungus (AMF) (Funneliformis mosseae). The SEM images illuminated that excessive nZVI particles (2 g·kg-1) were agglomerated on the surface of hyphae and spore, causing severe deformation and inactivation of AMF symbionts and thereafter inhibiting water uptake in maize seedlings. This restrained the scavenging effects of enzymatic (SOD, POD) and non-enzymatic compounds (proline & MDA) on ROS, and leaf photoreduction activity & gas exchange ability (p<0.05). Interestingly, the inoculation with AMF effectively alleviated above negative effects. In contrast, appropriate dose of nZVI, i.e. ≤1.5 g·kg-1 , can be evenly distributed on the hyphae surface and form the ordered symbionts with AMF. This help massively to enhance hyphae growth and water & nutrient uptake. The enhanced mycorrhizal infection turned to promote rhizosphere symbiont activity and leaf Rubisco & Rubisco activase activity. Light compensation point was massively lowered, which increased photosynthetic carbon supply for AMF symbionts. Particularly, such priming effects were evidently enhanced by drought stress. Our findings provided a novel insight into functional role of nZVI in agriculture and AMF-led green production. This article is protected by copyright. All rights reserved.

RevDate: 2022-11-02
CmpDate: 2022-11-02

Grieves LA, Bottini CLJ, Gloor GB, et al (2022)

Uropygial gland microbiota differ between free-living and captive songbirds.

Scientific reports, 12(1):18283.

Symbiotic microbes can affect host behavior and fitness. Gut microbiota have received the most study, with less attention to other important microbial communities like those of scent-producing glands such as mammalian anal glands and the avian uropygial gland. However, mounting evidence suggests that microbes inhabiting scent-producing glands play an important role in animal behavior by contributing to variation in chemical signals. Free-living and captive conditions typically differ in social environment, food diversity and availability, disease exposure, and other factors-all of which can translate into differences in gut microbiota. However, whether extrinsic factors such as captivity alter microbial communities in scent glands remains an open question. We compared the uropygial gland microbiota of free-living and captive song sparrows (Melospiza melodia) and tested for an effect of dietary manipulations on the gland microbiota of captive birds. As predicted, the uropygial gland microbiota was significantly different between free-living and captive birds. Surprisingly, microbial diversity was higher in captive than free-living birds, and we found no effect of dietary treatments on captive bird microbiota. Identifying the specific factors responsible for microbial differences among groups and determining whether changes in symbiotic microbiota alter behavior and fitness are important next steps in this field.

RevDate: 2022-11-02
CmpDate: 2022-11-02

Duan YF, Grogan P, Walker VK, et al (2022)

Whole genome sequencing of mesorhizobia isolated from northern Canada.

Canadian journal of microbiology, 68(11):661-673.

Rhizobia are soil-dwelling bacteria that can form N2-fixing symbioses with legume plant species (Fabaceae). These bacteria are globally distributed; however, few studies have examined the genomics of rhizobia that live in cold environments. Here, we isolated and characterized three rhizobial strains from legume nodules collected at a pair of distant low Arctic tundra and boreal forest sites in northern Canada. Phylogenetic and average nucleotide identity measurements suggested that the three strains are members of the genus Mesorhizobium, and that each strain represents a novel genospecies. Intriguingly, whereas most mesorhizobia contain the classical determinants of nodulation and nitrogen fixation on their chromosome, whole genome sequencing revealed that all three strains carry these genes on large symbiotic megaplasmids of ∼750 to ∼1000 kb. Phylogenetic and sequence analyses of the common nodulation genes revealed highly conserved alleles amongst these northern mesorhizobia, leading us to propose that they belong to a novel symbiovar that we termed symbiovar oxytropis. Interestingly, these nod gene alleles are uncommon in mesorhizobia isolated from similar plant hosts in other climatic regions, suggesting potential functional adaptive differences.

RevDate: 2022-11-02
CmpDate: 2022-11-02

Agbulu V, Zaman R, Ishangulyyeva G, et al (2022)

Host Defense Metabolites Alter the Interactions between a Bark Beetle and its Symbiotic Fungi.

Microbial ecology, 84(3):834-843.

Successful host plant colonization by tree-killing bark beetle-symbiotic fungal complexes depends on host suitability, which is largely determined by host defense metabolites such as monoterpenes. Studies have shown the ability of specific blends of host monoterpenes to influence bark beetles or their fungal symbionts, but how biologically relevant blends of host monoterpenes influence bark beetle-symbiotic fungal interaction is unknown. We tested how interactions between two host species (lodgepole pine or jack pine) and two fungal symbionts of mountain pine beetle (Grosmannia clavigera or Ophiostoma montium) affect the performance of adult female beetles in vitro. Beetles treated with the propagules of G. clavigera or O. montium or not treated (natural fungal load) were introduced into media amended with a blend of the entire monoterpene profile of either host species and beetle performance was compared. Overall, host blends altered beetle performance depending on the fungal species used in the beetle amendment. When beetles were amended with G. clavigera, their performance was superior over beetles amended with O. montium in either host blend. Furthermore, G. clavigera-amended beetles performed better in media amended with host blends than without a host blend; in contrast, O. montium-amended beetles performed better in media without a host blend than with a host blend. Overall, this study showed that host defense metabolites affect host suitability to bark beetles through influencing their fungal symbionts and that different species of fungal symbionts respond differentlly to host defense metabolites.

RevDate: 2022-11-01

Saxena B, Sharma K, Kapoor R, et al (2022)

Insights into the molecular aspects of salt stress tolerance in mycorrhizal plants.

World journal of microbiology & biotechnology, 38(12):253.

Salt stress is one of the major abiotic stresses that severely affect plant growth and yield, and also affect the livelihood of people all around the world. Arbuscular mycorrhizal fungi (AMF) colonize majority of terrestrial plants, including halophytes, xerophytes and glycophytes, and facilitate their functioning by various physiological, biochemical and molecular processes. In the past two decades, significant progress has been made to understand the role of AMF in mitigating salt stress and improving plant growth and productivity under saline conditions. Several studies focusing on the biochemical and physiological mechanisms that mycorrhizal plants employ to combat salt stress have been carried out. This review reinforces such studies and gives further insights into the molecular aspects of tolerance to salt stress in the plants colonized by AMF. It emphasises on the role of AMF in sensing and signalling salt stress, expression of aquaporin-encoding genes, Na+/H+ antiporters and transporters involved in Na+ exclusion, CNGCs and late embryogenesis abundant proteins in relation to salt stress tolerance. Further, this paper also reviews the accrual of compatible osmolytes, phytohormones and nitric oxide for understanding the benefits of this symbiosis under saline environment, and provides a benchmark information to understand the contribution of mycorrhizal symbiosis at molecular level and will attract attention of researchers to develop and highlight the future research programs in this field.

RevDate: 2022-10-31

Zhang Y, Li X, Hu A, et al (2022)

Effects of Hericium erinaceus Hedgehog mushroom on the endophytic microbial community of the host plant.

Journal of basic microbiology [Epub ahead of print].

Hedgehog mushroom is a Hericium erinaceus associated with fagaceae and pinaceae trees in the northern hemisphere. It is still unknown whether this symbiotic relationship will affect the endophytic microbial community of the host plants. In this study, the endophytic microbial communities of different Quercus aliena tissues (root, stem, and leaf) with or without H. erinaceus partner were analyzed by bar-coded pyrosequencing. About 29,000 clean reads were obtained per sample representing 28 phyla of bacteria and 6 phyla of fungi. A total of 26,838 operational taxonomic units (OTUs) of bacteria and 4323 OTUs of fungi were observed at a 97% similarity level. Three bacterial phyla, Proteobacteria, Cyanobacteria and Bacteroidetes, and fungal phylum Ascomycota were dominant in all tissues. The relative abundance of these dominant communities showed significantly differences between Q. aliena tissues with or without H. erinaceus. Bacterial genus Pseudomonas and fungal genus Cryptosporiopsis were species-rich in Q. aliena root infected by H. erinaceus hyphae. This study demonstrated that the endophytic microbial community structure and dominant species varied in Q. aliena mycorrhized with H. erinaceus.

RevDate: 2022-11-01
CmpDate: 2022-11-01

Kim KS (2022)

Regulation of T cell repertoires by commensal microbiota.

Frontiers in cellular and infection microbiology, 12:1004339.

The gut microbiota plays an important role in regulating the host immune systems. It is well established that various commensal microbial species can induce the differentiation of CD4+ T helper subsets such as Foxp3+ regulatory T (Treg) cells and Th17 cells in antigen-dependent manner. The ability of certain microbial species to induce either Treg cells or Th17 cells is often linked to the altered susceptibility to certain immune disorders that are provoked by aberrant T cell response against self-antigens. These findings raise an important question as to how gut microbiota can regulate T cell repertoire and the activation of autoreactive T cells. This review will highlight microbiota-dependent regulation of thymic T cell development, maintenance of T cell repertoire in the secondary lymphoid tissues and the intestine, and microbiota-mediated modulation of autoreactive and tumor neoantigen-specific T cells in autoimmune diseases and tumors, respectively.

RevDate: 2022-11-01
CmpDate: 2022-11-01

Blanchard S, Verheggen F, Van De Vreken I, et al (2022)

Combined Elevation of Temperature and CO2 Impacts the Production and Sugar Composition of Aphid Honeydew.

Journal of chemical ecology, 48(9-10):772-781.

Honeydew is the keystone of many interactions between aphids and their predators, parasitoids, and mutualistic partners. Despite the crucial importance of honeydew in aphid-ant mutualism, very few studies have investigated the potential impacts of climate change on its production and composition. Here, we quantified changes in sugar compounds and the amount of honeydew droplets released by Aphis fabae reared on Vicia faba plants under elevated temperature and/or CO2 conditions. Following the combined elevation of these two abiotic factors, we found a significant increase in the fructose content of A. fabae honeydew, accompanied by nonsignificant trends of increase in total honeydew production and melezitose content. The environmental conditions tested in this study did not significantly impact the other honeydew sugar contents. The observed changes may be related to changes in phloem composition under elevated CO2 conditions as well as to increases in aphid metabolism and sap ingestion under elevated temperatures. Although limited, such changes in aphid honeydew may concurrently reinforce ant attendance and mutualism under elevated temperature and CO2 conditions. Finally, we discuss the enhancing and counteracting effects of climate change on other biological agents (gut microorganisms, predators, and parasitoids) that interact with aphids in a complex multitrophic system.

RevDate: 2022-10-31

Shantz AA, Ladd MC, Ezzat L, et al (2022)

Positive interactions between corals and damselfish increase coral resistance to temperature stress.

Global change biology [Epub ahead of print].

By the century's end, many tropical seas will reach temperatures exceeding most coral species' thermal tolerance on an annual basis. The persistence of corals in these regions will, therefore, depend on their abilities to tolerate recurrent thermal stress. Although ecologists have long recognized that positive interspecific interactions can ameliorate environmental stress to expand the realized niche of plants and animals, coral bleaching studies have largely overlooked how interactions with community members outside of the coral holobiont shape the bleaching response. Here, we subjected a common coral, Pocillopora grandis, to 10 days of thermal stress in aquaria with and without the damselfish Dascyllus flavicaudus (yellowtail dascyllus), which commonly shelter within these corals, to examine how interactions with damselfish impacted coral thermal tolerance. Corals often benefit from nutrients excreted by animals they interact with and prior to thermal stress, corals grown with damselfish showed improved photophysiology (Fv /Fm) and developed larger endosymbiont populations. When exposed to thermal stress, corals with fish performed as well as control corals maintained at ambient temperatures without fish. In contrast, corals exposed to thermal stress without fish experienced photophysiological impairment, a more than 50% decline in endosymbiont density, and a 36% decrease in tissue protein content. At the end of the experiment, thermal stress caused average calcification rates to decrease by over 80% when damselfish were absent but increase nearly 25% when damselfish were present. Our study indicates that damselfish-derived nutrients can increase coral thermal tolerance and are consistent with the Stress Gradient Hypothesis, which predicts that positive interactions become increasingly important for structuring communities as environmental stress increases. Because warming of just a few degrees can exceed corals' temperature tolerance to trigger bleaching and mortality, positive interactions could play a critical role in maintaining some coral species in warming regions until climate change is aggressively addressed.

RevDate: 2022-10-31

Schmidt EW, Z Lin (2022)

Translating Marine Symbioses toward Drug Development.

mBio [Epub ahead of print].

Chemists have studied marine animals for the better part of a century because they contain a diverse array of bioactive compounds. Tens of thousands of compounds have been reported, many with elaborate structural motifs and biological mechanisms of action found nowhere else. The challenge holding back the field has long been that of supply. Compounds are sometimes obtained by cultivating marine animals or by wild harvest, but this often presents logistical and environmental challenges. Some of the most medically important marine animal compounds are supplied by synthesis, often through multistep procedures that delay drug development. A relatively small number of such agents have been approved by the U.S. Food and Drug Administration, often after a heroic effort. In a recent mBio paper, Uppal and coworkers ( address key hurdles underlying the supply issue, discovering an uncultivated new bacterial genus from a marine sponge and reconstituting the biosynthetic pathway for expression.

RevDate: 2022-10-31

Khanna K, Kohli SK, Bhardwaj R, et al (2022)

Editorial: Portraying the phytomicrobiome studies during abiotic stresses: Revisiting the past and exploring the future outcomes.

Frontiers in microbiology, 13:1015149.

RevDate: 2022-10-31

Wang Y, Chen P, Yu X, et al (2022)

Algae-bacteria symbiotic constructed wetlands for antibiotic wastewater purification and biological response.

Frontiers in microbiology, 13:1044009.

In this work, the removal efficiency and mechanism of various constructed wetlands microcosm systems on antibiotic wastewater, as well as the biological community response of microalgae and microorganisms were explored. Overall, the algal-bacteria symbiosis in conjunction with the gravel matrix had the most comprehensive treatment efficiency for antibiotic wastewater. However, pollutants such as high-concentration antibiotics impaired the biological community and functions. In the systems fed with microorganisms, both abundance and diversity of them were significantly reduced comparing with the initial value. According to the correlation analysis revealed that the pollutants removal rate increased with the addition of the relative abundance of some bacterial genera, while decreased with the addition of relative abundance of other bacterial genera. The presence of gravel matrix could lessen the stressful effect of antibiotics and other pollutants on the growth of microalgae and microorganisms, as well as improved treatment efficiency of antibiotic wastewater. Based on the findings of the study, the combination of gravel matrix and algal-bacteria symbiosis can considerably increase the capacity of constructed wetlands to treat antibiotic wastewater and protect biological community, which is an environmentally friendly way.

RevDate: 2022-10-31

Taboada-Castro H, Gil J, Gómez-Caudillo L, et al (2022)

Rhizobium etli CFN42 proteomes showed isoenzymes in free-living and symbiosis with a different transcriptional regulation inferred from a transcriptional regulatory network.

Frontiers in microbiology, 13:947678.

A comparative proteomic study at 6 h of growth in minimal medium (MM) and bacteroids at 18 days of symbiosis of Rhizobium etli CFN42 with the Phaseolus vulgaris leguminous plant was performed. A gene ontology classification of proteins in MM and bacteroid, showed 31 and 10 pathways with higher or equal than 30 and 20% of proteins with respect to genome content per pathway, respectively. These pathways were for energy and environmental compound metabolism, contributing to understand how Rhizobium is adapted to the different conditions. Metabolic maps based on orthology of the protein profiles, showed 101 and 74 functional homologous proteins in the MM and bacteroid profiles, respectively, which were grouped in 34 different isoenzymes showing a great impact in metabolism by covering 60 metabolic pathways in MM and symbiosis. Taking advantage of co-expression of transcriptional regulators (TF's) in the profiles, by selection of genes whose matrices were clustered with matrices of TF's, Transcriptional Regulatory networks (TRN´s) were deduced by the first time for these metabolic stages. In these clustered TF-MM and clustered TF-bacteroid networks, containing 654 and 246 proteins, including 93 and 46 TFs, respectively, showing valuable information of the TF's and their regulated genes with high stringency. Isoenzymes were specific for adaptation to the different conditions and a different transcriptional regulation for MM and bacteroid was deduced. The parameters of the TRNs of these expected biological networks and biological networks of E. coli and B. subtilis segregate from the random theoretical networks. These are useful data to design experiments on TF gene-target relationships for bases to construct a TRN.

RevDate: 2022-10-31

Miyokawa R, Hanada M, Togawa Y, et al (2022)

Symbiont specificity differs among green hydra strains.

Royal Society open science, 9(10):220789 pii:rsos220789.

The symbiotic hydra Hydra viridissima has a stable symbiotic relationship with the green alga Chlorella. This hydra appears to cospeciate with the symbiotic alga, and some strains are known to have strain-specific host/symbiont combinations. To investigate the mechanism of the specificity between host and symbiont, we explored the effect of the removal or exchange of symbionts in two distantly related H. viridissima strains (K10 and M9). In the K10 strain, severe morphological and behavioural changes were found in symbiont-removed and symbiont-exchanged polyps. Interestingly, both polyps showed a similar gene expression pattern. The gene ontology (GO) enrichment analysis revealed that the removal or exchange of symbionts caused the downregulation of genes involved in the electron transport chain and the upregulation of genes involved in translation in the K10 strain. On the other hand, symbiont-removed and symbiont-exchanged M9 polyps showed modest changes in their morphology and behaviour compared with the K10 strain. Furthermore, the patterns of the gene expression changes in the M9 strain were quite different between the symbiont-removed and symbiont-exchanged polyps. Our results suggested that the regulation of energy balance is one of the crucial mechanisms for maintaining symbiotic relationships in green hydra, and this mechanism differs between the strains.

RevDate: 2022-10-31

Singh P, Kaur S, Baabdullah AM, et al (2022)

Is #SDG13 Trending Online? Insights from Climate Change Discussions on Twitter.

Information systems frontiers : a journal of research and innovation pii:10348 [Epub ahead of print].

Anthropogenic activities over the past few decades have led to increased vulnerability of environmental and ecological stability on this planet. Accelerated climate change is one such subset of the environmental problems that threatens the very existence of humankind in twenty first century. Governments, United Nations (UN) and other humanitarian agencies across the globe have developed and devised strategies for climate action that requires grater public awareness and actions. Social media has played a vital role in information dissemination and raising public awareness of climate change in the digital era. To this aid, an upsurge has been documented in recent times regarding discussions over climate change with #SDG13 (Sustainable Development Goals) at its epicenter. Following the principles of Actor Network Theory (ANT) we analyzed a large volume of Twitter data to understand general citizens' perception and attitude towards climate change. Our findings unveil people's opinion on causes and concerns related to barriers of adopting a more sustainable consumption and lifestyle practice. There is also a growing apathy towards sluggish government actions that makes little difference. People were also found to exchange innovative concepts and measures towards mitigating the effects of climate change.

RevDate: 2022-10-31

Lerer V, N Shlezinger (2022)

Inseparable companions: Fungal viruses as regulators of fungal fitness and host adaptation.

Frontiers in cellular and infection microbiology, 12:1020608.

RevDate: 2022-10-31

Croce N, Pitaro M, Gallo V, et al (2022)

Toxicity of Usnic Acid: A Narrative Review.

Journal of toxicology, 2022:8244340.

Usnic acid (UA) is a dibenzofuran derivative naturally present in lichens, organisms resulting from the symbiosis between a fungus and a cyanobacterium, or an alga. UA shows antimicrobial, antitumor, antioxidant, analgesic, anti-inflammatory as well as UV-protective activities. Its use as pharmacological agent is widely described in traditional medicine, and in the past few years, the product has been marketed as a food supplement for the induction of weight loss. However, the development of severe hepatotoxicity in a limited number of subjects prompted the FDA to issue a warning letter, which led to the withdrawal of the product from the market in November 2001. Data published in literature on UA toxicology, genotoxicity, mutagenesis, and teratogenicity have been reviewed, as well as the case reports of subjects who developed hepatotoxicity following oral administration of UA as a slimming agent. Finally, we reviewed the most recent studies on the topical use of UA, as well as studies aimed at improving UA pharmacologic activity and reducing toxicity. Indeed, advancements in this field of research could open the possibility to reintroduce the use of UA as therapeutical agent.

RevDate: 2022-10-30

Bastías DA, PE Gundel (2022)

Plant stress responses compromise mutualisms with Epichloë endophytes.

Journal of experimental botany pii:6780278 [Epub ahead of print].

Plants commonly form mutualistic associations with fungal endophytes. We put forward the hypothesis, with supporting evidence, that certain plant physiological responses to stress (i.e., phytohormones and ROS) change the symbiosis between plants and Epichloë endophytes from mutualistic to parasitic. The negative effects of the plant physiological responses on the endophyte performance would explain the change in the symbiosis outcome. Furthermore, we posit that endophytes may protect the mutualism by the induction of plant defence hormone responses and antioxidants.

RevDate: 2022-10-30

Budgude P, Vaidya A, V Kale (2022)

Cell-intrinsic factors governing quiescence vis-à-vis activation of adult hematopoietic stem cells.

Molecular and cellular biochemistry [Epub ahead of print].

Hematopoiesis is a highly complex process, regulated by both intrinsic and extrinsic factors. Often, these two regulatory arms work in tandem to maintain the steady-state condition of hematopoiesis. However, at times, certain intrinsic attributes of hematopoietic stem cells (HSCs) override the external stimuli and dominate the outcome. These could be genetic events like mutations or environmentally induced epigenetic or transcriptomic changes. Since leukemic stem cells (LSCs) share molecular pathways that also regulate normal HSCs, identifying specific, dominantly acting intrinsic factors could help in the development of novel therapeutic approaches. Here we have reviewed such dominantly acting intrinsic factors governing quiescence vis-à-vis activation of the HSCs in the face of external forces acting on them. For brevity, we have restricted our review to the articles dealing with adult HSCs of human and mouse origin that have been published in the last 10 years. Hematopoietic stem cells (HSCs) are closely associated with various stromal cells in their microenvironment and, thus, constantly receive signaling cues from them. The illustration depicts some dominantly acting intrinsic or cell-autonomous factors operative in the HSCs. These fall into various categories, such as epigenetic regulators, transcription factors, cell cycle regulators, tumor suppressor genes, signaling pathways, and metabolic regulators, which counteract the outcome of extrinsic signaling exerted by the HSC niche.

RevDate: 2022-10-31
CmpDate: 2022-10-31

Cao Y, Oh J, Xue M, et al (2022)

Commensal microbiota from patients with inflammatory bowel disease produce genotoxic metabolites.

Science (New York, N.Y.), 378(6618):eabm3233.

Microbiota-derived metabolites that elicit DNA damage can contribute to colorectal cancer (CRC). However, the full spectrum of genotoxic chemicals produced by indigenous gut microbes remains to be defined. We established a pipeline to systematically evaluate the genotoxicity of an extensive collection of gut commensals from inflammatory bowel disease patients. We identified isolates from divergent phylogenies whose metabolites caused DNA damage and discovered a distinctive family of genotoxins-termed the indolimines-produced by the CRC-associated species Morganella morganii. A non-indolimine-producing M. morganii mutant lacked genotoxicity and failed to exacerbate colon tumorigenesis in mice. These studies reveal the existence of a previously unexplored universe of genotoxic small molecules from the microbiome that may affect host biology in homeostasis and disease.

RevDate: 2022-10-29

Davray D, Bawane H, R Kulkarni (2023)

Non-redundant nature of Lactiplantibacillus plantarum plasmidome revealed by comparative genomic analysis of 105 strains.

Food microbiology, 109:104153.

Lactiplantibacillus plantarum is a homofermentative lactic acid bacterium (LAB) most often found in fermented foods with many strains displaying probiotic properties. Strains belonging to L. plantarum are more stress tolerant and metabolically flexible than other lactobacilli and display larger genomes and higher plasmid abundance. This study aimed at understanding whether plasmids play a particular role in L. plantarum as compared to chromosomes by comparative genomic analysis. Assessment of chromosomes and 395 plasmids of 105 strains with publicly available complete genome sequences revealed that the majority of the plasmids encoded protein families (PFs) (57.6%) were not encoded by the chromosomes. The most abundant PFs unique to plasmids contained hypothetical proteins while others were involved in exopolysaccharides biosynthesis, biofilm formation, stress tolerance, and carbohydrate metabolism. The sequences of common plasmid-encoded and chromosome-encoded PFs differed from each other, suggesting that they might exhibit different biochemical properties. Common PF genes were predominantly present on larger plasmids pointing to another possible way to reduce redundancy by encoding shared PFs by low copy number plasmids. Overall, this study demonstrates the unique contributions of the plasmids to the versatility, survival, and evolutionary success of L. plantarum while also highlighting a need to functionally characterize hypothetical proteins encoded by them.

RevDate: 2022-10-28

Fu Y, Ren Y, W Pei (2022)

Evaluation of the symbiosis level of the water-energy-food complex system based on the improved cloud model: a case study in Heilongjiang Province.

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

As the conflict between the supply and demand of resources intensifies, it is critical to deeply study the important relationships and symbiotic evolution mechanisms among water resource development and utilization, energy production, agriculture, and the socioeconomic system to promote multiresource synergy management. This study introduced symbiosis theory to build a regional water-energy-food complex system in which the water-energy-food nexus was the main body and the social-economic-natural system was the external environment. Then, a symbiosis evaluation index system was established from three dimensions, including the symbiotic unit, symbiotic relationship, and symbiotic environment. Using the improved cloud model, we judged the symbiosis level of the water-energy-food complex system in Heilongjiang Province from 2010 to 2019. The results indicated that (1) the symbiosis level of the provincial water-energy-food complex system, symbiotic unit, and symbiotic environment was on the rise from level II in 2010 to level IV in 2019, and the symbiosis level of the symbiotic unit fluctuated between level III and level IV. The system exhibited an overall strong symbiosis state. (2) The weights of the three criteria were ranked as symbiotic environment > symbiotic unit > symbiotic relationship. The state of the social-economic-natural system could be considered a "monitor" of the symbiosis level, the symbiotic unit was an important basis for the evolution of the complex system, and the symbiotic relationship was the shortcoming of the system symbiosis enhancement. (3) The trade-offs between food production and water savings constrained socioeconomic development in the province. The resource demands of the economic and social systems and the emissions to the natural system that occurred during the resource exploitation and utilization processes were important factors affecting the coordinated development of the studied system. Overall, the experimental results were consistent with the research subjects' actual situations, and the government should promote the regional three-way flow of social, natural, and economic resources to allow the targeted management of multiresource security.

RevDate: 2022-10-28

Li XR, Sun J, Albinsky D, et al (2022)

Nutrient regulation of lipochitooligosaccharide recognition in plants via NSP1 and NSP2.

Nature communications, 13(1):6421.

Many plants associate with arbuscular mycorrhizal fungi for nutrient acquisition, while legumes also associate with nitrogen-fixing rhizobial bacteria. Both associations rely on symbiosis signaling and here we show that cereals can perceive lipochitooligosaccharides (LCOs) for activation of symbiosis signaling, surprisingly including Nod factors produced by nitrogen-fixing bacteria. However, legumes show stringent perception of specifically decorated LCOs, that is absent in cereals. LCO perception in plants is activated by nutrient starvation, through transcriptional regulation of Nodulation Signaling Pathway (NSP)1 and NSP2. These transcription factors induce expression of an LCO receptor and act through the control of strigolactone biosynthesis and the karrikin-like receptor DWARF14-LIKE. We conclude that LCO production and perception is coordinately regulated by nutrient starvation to promote engagement with mycorrhizal fungi. Our work has implications for the use of both mycorrhizal and rhizobial associations for sustainable productivity in cereals.

RevDate: 2022-10-28

Kuerer HM, Smith BD, Krishnamurthy S, et al (2022)

Eliminating breast surgery for invasive breast cancer in exceptional responders to neoadjuvant systemic therapy: a multicentre, single-arm, phase 2 trial.

The Lancet. Oncology pii:S1470-2045(22)00613-1 [Epub ahead of print].

BACKGROUND: Neoadjuvant systemic therapy (NST) for triple-negative breast cancer and HER2-positive breast cancer yields a pathological complete response in approximately 60% of patients. A pathological complete response to NST predicts an excellent prognosis and can be accurately determined by percutaneous image-guided vacuum-assisted core biopsy (VACB). We evaluated radiotherapy alone, without breast surgery, in patients with early-stage triple-negative breast cancer or HER2-positive breast cancer treated with NST who had an image-guided VACB-determined pathological complete response.

METHODS: This multicentre, single-arm, phase 2 trial was done in seven centres in the USA. Women aged 40 years or older who were not pregnant with unicentric cT1-2N0-1M0 triple-negative breast cancer or HER2-positive breast cancer and a residual breast lesion less than 2 cm on imaging after clinically standard NST were eligible for inclusion. Patients had one biopsy (minimum of 12 cores) obtained by 9G image-guided VACB of the tumour bed. If no invasive or in-situ disease was identified, breast surgery was omitted, and patients underwent standard whole-breast radiotherapy (40 Gy in 15 fractions or 50 Gy in 25 fractions) plus a boost (14 Gy in seven fractions). The primary outcome was the biopsy-confirmed ipsilateral breast tumour recurrence rate determined using the Kaplan-Meier method assessed in the per-protocol population. Safety was assessed in all patients who received VACB. This study has completed accrual and is registered with, NCT02945579.

FINDINGS: Between March 6, 2017, and Nov 9, 2021, 58 patients consented to participate; however, four (7%) did not meet final inclusion criteria and four (7%) withdrew consent. 50 patients were enrolled and underwent VACB following NST. The median age of the enrolled patients was 62 years (IQR 55-77); 21 (42%) patients had triple-negative breast cancer and 29 (58%) had HER2-positive breast cancer. VACB identified a pathological complete response in 31 patients (62% [95% CI 47·2-75·4). At a median follow-up of 26·4 months (IQR 15·2-39·6), no ipsilateral breast tumour recurrences occurred in these 31 patients. No serious biopsy-related adverse events or treatment-related deaths occurred.

INTERPRETATION: Eliminating breast surgery in highly selected patients with an image-guided VACB-determined pathological complete response following NST is feasible with promising early results; however, additional prospective clinical trials evaluating this approach are needed.

FUNDING: US National Cancer Institute (National Institutes of Health).

RevDate: 2022-10-28

Sun C, Guo Q, Zeeshan M, et al (2022)

Dual RNA and 16S ribosomal DNA sequencing reveal arbuscular mycorrhizal fungi-mediated mitigation of selenate stress in Zea mays L. and reshaping of soil microbiota.

Ecotoxicology and environmental safety, 247:114217 pii:S0147-6513(22)01057-0 [Epub ahead of print].

Excessively high concentrations of selenium (Se) in soil are toxic to crop plants, and inoculation with arbuscular mycorrhizal fungi (AMF) can reverse Se stress in maize (Zea mays L.). To investigate the underlying mechanisms, maize seedlings were treated with sodium selenate (5 mg Se[VI] kg-1) and/or AMF (Funneliformis mosseae and Claroideoglomus etunicatum). Dual RNA sequencing in mycorrhiza and 16 S ribosomal DNA sequencing in soil were performed. The results showed that Se(VI) application alone decreased plant dry weight, but increased plant Se concentration, total Se content (mainly selenocysteine), and root superoxide content. Inoculation with either F. mosseae or C. etunicatum increased plant dry weight, decreased Se accumulation and selenocysteine proportion, enhanced root peroxidase activity, and alleviated oxidative stress in Se(VI)-treated plants. Inoculation also downregulated the expression of genes encoding Se transporters, assimilation enzymes, and cysteine-rich receptor-like kinases in Se(VI)-stressed plants, similar to plant-pathogen interaction and glutathione metabolism related genes. Conversely, genes encoding selenium-binding proteins and those related to phenylpropanoid biosynthesis were upregulated in inoculated plants under Se(VI) stress. Compared with Se(VI)-free plants, Se tolerance index, symbiotic feedback percentage on plant dry weight, and root colonization rate were all increased in inoculated plants under Se(VI) stress, corresponding to upregulated expression of 'key genes' in symbiosis. AMF inoculation increased bacterial diversity, decreased the relative abundances of selenobacteria related to plant Se absorption (e.g., Proteobacteria and Firmicutes), and improved bacterial network complexity in Se(VI)-stressed soils. We suggest that stress-mediated enhancement of mycorrhizal symbiosis contributed to plant Se(VI) tolerance, whereas AMF-mediated reshaping of soil bacterial community structure prevented excessive Se accumulation in maize.

RevDate: 2022-10-28

Berrabah F, Bernal G, Elhosseyn AS, et al (2022)

Insight into the control of nodule immunity and senescence during Medicago truncatula symbiosis.

Plant physiology pii:6777271 [Epub ahead of print].

Medicago (Medicago truncatula) establishes a symbiosis with the rhizobia Sinorhizobium sp, resulting in the formation of nodules where the bacteria fix atmospheric nitrogen. Loss of immunity repression or early senescence activation compromises symbiont survival and leads to the formation of non-functional nodules (fix-). Despite many studies exploring an overlap between immunity and senescence responses outside the nodule context, the relationship between these processes in the nodule remains poorly understood. To investigate this phenomenon we selected and characterized three Medicago mutants developing fix- nodules and showing senescence responses. Analysis of specific defense (PATHOGENESIS-RELATED PROTEIN) or senescence (CYSTEINE PROTEASE) marker expression demonstrated that senescence and immunity seem to be antagonistic in fix- nodules. Growth of senescence mutants on non-sterile (sand/perlite) substrate instead of sterile in vitro conditions decreased nodule senescence and enhanced defense, indicating that environment can affect the immunity/senescence balance. Application of wounding stress on WT fix+ nodules led to the death of intracellular rhizobia and associated with co-stimulation of defense and senescence markers, indicating that in fix+ nodules the relationship between the two processes switches from opposite to synergistic to control symbiont survival during response to the stress. Our data show that the immune response in stressed WT nodules is linked to repression of DEFECTIVE IN NITROGEN FIXATION 2 (DNF2), Symbiotic CYSTEINE-RICH RECEPTOR-LIKE KINASE (SymCRK) and REGULATOR OF SYMBIOSOME DIFFERENTIATION (RSD), key genes involved in symbiotic immunity suppression. This study provides insight to understand the links between senescence and immunity in Medicago nodules.

RevDate: 2022-10-28

Parshuram ZA, Harrison TL, Simonsen AK, et al (2022)

Non-symbiotic legumes are more invasive, but only if polyploid.

The New phytologist [Epub ahead of print].

● Both mutualism and polyploidy are thought to influence invasion success in plants but few studies have tested their joint effects. Mutualism can limit range expansion when plants cannot find a compatible partner in a novel habitat, or facilitate range expansion when mutualism increases a plant's niche breadth. Polyploids are also expected to have greater niche breadth because of greater self-compatibility and phenotypic plasticity, increasing invasion success. ● For 847 legume species, we compiled data from published sources to estimate ploidy, symbiotic status with rhizobia, specificity on rhizobia, and the number of introduced ranges. ● We found that diploid species have had limited spread around the globe regardless of whether they are symbiotic or how many partners of rhizobia they can host. Polyploids, in contrast, have been successfully introduced to many new ranges, but interactions with rhizobia constrain their range expansion. In a hidden state model of trait evolution, we also found evidence of a high rate of re-diploidization in symbiotic legume lineages, suggesting that symbiosis and ploidy may interact at macroevolutionary scales. ● Overall, our results suggest that symbiosis with rhizobia limits range expansion when legumes are polyploid but not diploid.

RevDate: 2022-10-28

Ban Y, Tan J, Xiong Y, et al (2023)

Transcriptome analysis reveals the molecular mechanisms of Phragmites australis tolerance to CuO-nanoparticles and/or flood stress induced by arbuscular mycorrhizal fungi.

Journal of hazardous materials, 442:130118.

The molecular mechanism of arbuscular mycorrhizal fungi (AMF) in vertical flow constructed wetlands (VFCWs) for the purification of copper oxide nanoparticles (CuO-NPs) contaminated wastewater remains unclear. In this study, transcriptome analysis was used to explore the effect of AMF inoculation on the gene expression profile of Phragmites australis roots under different concentrations of CuO-NPs and/or flood stress. 551, 429 and 2281 differentially expressed genes (DEGs) were specially regulated by AMF under combined stresses of CuO-NPs and flood, single CuO-NPs stress and single flood stress, respectively. Based on the results of DEG function annotation and enrichment analyses, AMF inoculation under CuO-NPs and/or flood stress up-regulated the expression of a number of genes involved in antioxidant defense systems, cell wall biosynthesis and transporter protein, which may contribute to plant tolerance. The expression of 30 transcription factors (TFs) was up-regulated by AMF inoculation under combined stresses of CuO-NPs and flood, and 44 and 44 TFs were up-regulated under single CuO-NPs or flood condition, respectively, which may contribute to the alleviating effect of symbiosis on CuO-NPs and/or flood stress. These results provided a theoretical basis for enhancing the ecological restoration function of wetland plants for metallic nanoparticles (MNPs) by mycorrhizal technology in the future.

RevDate: 2022-10-27

Spanner C, Darienko T, Filker S, et al (2022)

Morphological diversity and molecular phylogeny of five Paramecium bursaria (Alveolata, Ciliophora, Oligohymenophorea) syngens and the identification of their green algal endosymbionts.

Scientific reports, 12(1):18089.

Paramecium bursaria is a mixotrophic ciliate species, which is common in stagnant and slow-flowing, nutrient-rich waters. It is usually found living in symbiosis with zoochlorellae (green algae) of the genera Chlorella or Micractinium. We investigated P. bursaria isolates from around the world, some of which have already been extensively studied in various laboratories, but whose morphological and genetic identity has not yet been completely clarified. Phylogenetic analyses of the SSU and ITS rDNA sequences revealed five highly supported lineages, which corresponded to the syngen and most likely to the biological species assignment. These syngens R1-R5 could also be distinguished by unique synapomorphies in the secondary structures of the SSU and the ITS. Considering these synapomorphies, we could clearly assign the existing GenBank entries of P. bursaria to specific syngens. In addition, we discovered synapomorphies at amino acids of the COI gene for the identification of the syngens. Using the metadata of these entries, most syngens showed a worldwide distribution, however, the syngens R1 and R5 were only found in Europe. From morphology, the syngens did not show any significant deviations. The investigated strains had either Chlorella variabilis, Chlorella vulgaris or Micractinium conductrix as endosymbionts.

RevDate: 2022-10-28
CmpDate: 2022-10-28

Ip JC, Zhang Y, Xie JY, et al (2022)

Stable Symbiodiniaceae composition in three coral species during the 2017 natural bleaching event in subtropical Hong Kong.

Marine pollution bulletin, 184:114224.

Adaptive changes in endosymbiotic Symbiodiniaceae communities have been reported during and after bleaching events in tropical coral species, but little is known about such shifts in subtropical species. Here we examined the Symbiodiniaceae communities in three coral species (Montipora peltiformis, Pavona decussata, and Platygyra carnosa) based on samples collected during and after the 2017 bleaching event in subtropical Hong Kong waters. In all of the collected samples, ITS2 meta-sequencing revealed that P. decussata and P. carnosa were predominantly associated with Cladocopium C1 and C1c, whereas M. peltiformis was mainly associated with two Cladocopium C21 types and C1. For each species, the predominant endosymbionts exhibited high fidelity, and the relatively low abundance ITS2-types showed minor changes between the bleached and recovered corals. Our study provided the first details of coral-algal association in Hong Kong waters, suggesting the selection of certain genotypes as a potential adaptive mechanism to the marginal environmental conditions.

RevDate: 2022-10-28
CmpDate: 2022-10-28

Peroumal D, Sahu SR, Kumari P, et al (2022)

Commensal Fungus Candida albicans Maintains a Long-Term Mutualistic Relationship with the Host To Modulate Gut Microbiota and Metabolism.

Microbiology spectrum, 10(5):e0246222.

Candida albicans survives as a commensal fungus in the gastrointestinal tract, and that its excessive growth causes infections in immunosuppressed individuals is widely accepted. However, any mutualistic relationship that may exist between C. albicans and the host remains undetermined. Here, we showed that a long-term feeding of C. albicans does not cause any noticeable infections in the mouse model. Our 16S and 18S ribosomal DNA (rDNA) sequence analyses suggested that C. albicans colonizes in the gut and modulates microbiome dynamics, which in turn mitigates high-fat-diet-induced uncontrolled body weight gain and metabolic hormonal imbalances. Interestingly, adding C. albicans to a nonobesogenic diet stimulated the appetite-regulated hormones and helped the mice maintain a healthy body weight. In concert, our results suggest a mutualism between C. albicans and the host, contrary to the notion that C. albicans is always an adversary and indicating it can instead be a bona fide admirable companion of the host. Finally, we discuss its potential translational implication as a probiotic, especially in obese people or people dependent on high-fat calorie intakes to manage obesity associated complications. IMPORTANCE Candida albicans is mostly considered an opportunistic pathogen that causes fetal systemic infections. However, this study demonstrates that in its commensal state, it maintains a long-term mutualistic relationship with the host and regulates microbial dynamics in the gut and host physiology. Thus, we concluded that C. albicans is not always an adversary but rather can be a bona fide admirable companion of the host. More importantly, as several genomic knockout strains of C. albicans were shown to be avirulent, such candidate strains may be explored further as preferable probiotic isolates to control obesity.

RevDate: 2022-10-28
CmpDate: 2022-10-28

Kinjo Y, Bourguignon T, Hongoh Y, et al (2022)

Coevolution of Metabolic Pathways in Blattodea and Their Blattabacterium Endosymbionts, and Comparisons with Other Insect-Bacteria Symbioses.

Microbiology spectrum, 10(5):e0277922.

Many insects harbor bacterial endosymbionts that supply essential nutrients and enable their hosts to thrive on a nutritionally unbalanced diet. Comparisons of the genomes of endosymbionts and their insect hosts have revealed multiple cases of mutually-dependent metabolic pathways that require enzymes encoded in 2 genomes. Complementation of metabolic reactions at the pathway level has been described for hosts feeding on unbalanced diets, such as plant sap. However, the level of collaboration between symbionts and hosts that feed on more variable diets is largely unknown. In this study, we investigated amino acid and vitamin/cofactor biosynthetic pathways in Blattodea, which comprises cockroaches and termites, and their obligate endosymbiont Blattabacterium cuenoti (hereafter Blattabacterium). In contrast to other obligate symbiotic systems, we found no clear evidence of "collaborative pathways" for amino acid biosynthesis in the genomes of these taxa, with the exception of collaborative arginine biosynthesis in 2 taxa, Cryptocercus punctulatus and Mastotermes darwiniensis. Nevertheless, we found that several gaps specific to Blattabacterium in the folate biosynthetic pathway are likely to be complemented by their host. Comparisons with other insects revealed that, with the exception of the arginine biosynthetic pathway, collaborative pathways for essential amino acids are only observed in phloem-sap feeders. These results suggest that the host diet is an important driving factor of metabolic pathway evolution in obligate symbiotic systems. IMPORTANCE The long-term coevolution between insects and their obligate endosymbionts is accompanied by increasing levels of genome integration, sometimes to the point that metabolic pathways require enzymes encoded in two genomes, which we refer to as "collaborative pathways". To date, collaborative pathways have only been reported from sap-feeding insects. Here, we examined metabolic interactions between cockroaches, a group of detritivorous insects, and their obligate endosymbiont, Blattabacterium, and only found evidence of collaborative pathways for arginine biosynthesis. The rarity of collaborative pathways in cockroaches and Blattabacterium contrasts with their prevalence in insect hosts feeding on phloem-sap. Our results suggest that host diet is a factor affecting metabolic integration in obligate symbiotic systems.

RevDate: 2022-10-28
CmpDate: 2022-10-28

Ashrafi S, Kuzmanović N, Patz S, et al (2022)

Two New Rhizobiales Species Isolated from Root Nodules of Common Sainfoin (Onobrychis viciifolia) Show Different Plant Colonization Strategies.

Microbiology spectrum, 10(5):e0109922.

Root nodules of legume plants are primarily inhabited by rhizobial nitrogen-fixing bacteria. Here, we propose two new Rhizobiales species isolated from root nodules of common sainfoin (Onobrychis viciifolia), as shown by core-gene phylogeny, overall genome relatedness indices, and pan-genome analysis. Mesorhizobium onobrychidis sp. nov. actively induces nodules and achieves atmospheric nitrogen and carbon dioxide fixation. This species appears to be depleted in motility genes and is enriched in genes for direct effects on plant growth performance. Its genome reveals functional and plant growth-promoting signatures, like a large unique chromosomal genomic island with high density of symbiotic genetic traits. Onobrychidicola muellerharveyae gen. nov. sp. nov. is described as a type species of the new genus Onobrychidicola in Rhizobiaceae. This species comprises unique genetic features and plant growth-promoting traits (PGPTs), which strongly indicate its function in biotic stress reduction and motility. We applied a newly developed bioinformatics approach for in silico prediction of PGPTs (PGPT-Pred), which supports the different lifestyles of the two new species and the plant growth-promoting performance of M. onobrychidis in the greenhouse trial. IMPORTANCE The intensive use of chemical fertilizers has a variety of negative effects on the environment. Increased utilization of biological nitrogen fixation (BNF) is one way to mitigate those negative impacts. In order to optimize BNF, suitable candidates for different legume species are required. Despite intensive search for new rhizobial bacteria associated with legumes, no new rhizobia have recently been identified from sainfoin (Onobrychis viciifolia). Here, we report on the discovery of two new rhizobial species associated with sainfoin, which are of high importance for the host and may help to increase sustainability in agricultural practices. We employed the combination of in silico prediction and in planta experiments, which is an effective way to detect promising plant growth-promoting bacteria.

RevDate: 2022-10-27

Sun J, Liu G, X Yuan (2022)

Alternative stable state and its evaluation in wetland reconstruction based on landscape design.

The Science of the total environment pii:S0048-9697(22)06742-0 [Epub ahead of print].

An alternative stable state is closely related to the health and sustainable development of ecosystems; however, knowledge of the alternative stable state and its quantitative evaluation in wetland reconstruction remains incomplete. In this study, we used landscape design to reconstruct an optimized ecological polder wetland and a lake wetland in the Yunmeng Marsh area, China, and the alternative stable states of the two wetland ecosystems were assessed from an ecosystem perspective via emergy/eco-exergy and fractal dimensions. The emergy densities for the optimized ecological polder wetland and the lake wetland were 2.35E+13 sej yr-1 m-3 and 2.18E+13 sej m-3, and the emergy sustainability index (ESI) values were 216.57 and 193.31, respectively, indicating that the reconstructed wetland ecosystems were dominated by renewable energy flows and were highly sustainable. The eco-exergy density and emergy/eco-exergy ratio results showed that natural selection self-organized the reconstructed wetland ecosystems to tolerate environmental stresses and changes. In addition, the fractal dimensions of the morphology and contour of the polder wetland, which reflect the space occupation capacity of geometric and physical constraints in the wetland, were 1.57 and 1.75, and those of the lake wetland were 1.03 and 1.47, respectively. The synthetic evaluation results showed that the alternative stable states of both the optimized ecological polder wetland ecosystem and the lake wetland ecosystem were ecofriendly modes of wetland reconstruction, which can be implemented together to create a "lake-polder" ecosystem. Our study on the alternative stable states of wetland ecosystems is helpful for exploring the synergistic symbiosis between traditional culture and the ecological environment in China and other wetland-rich regions and countries with severe disturbances.

RevDate: 2022-10-27

Ignatenko ME, TN Yatsenko-Stepanova (2022)

Diversity of Chrysophycean Stomatocysts in the Steppe Zone of the South Urals.

Doklady biological sciences : proceedings of the Academy of Sciences of the USSR, Biological sciences sections, 506(1):184-190.

Diversity of chrysophycean stomatocysts was studied in the steppe zone of the South Urals. A total of 14 stomatocyst morphotypes were identified, of which four were for the first time observed in Russia. Two morphotypes were described as novel. Morphological descriptions, scanning electron microscopic (SEM) images, and geographical locations were provided for all stomatocysts. High diversity of chrysophycean stomatocysts points to significant development of the chrysophyte flora in reservoirs of the steppe zone of the South Urals, making further research relevant.

RevDate: 2022-10-27

Rimskaya-Korsakova NN, Temereva EN, VV Malakhov (2022)

Apoptotic Processes Precede Infection with Symbionts in a Pogonophoran Lavrae (Siboglinidae, Annelida).

Doklady biological sciences : proceedings of the Academy of Sciences of the USSR, Biological sciences sections, 506(1):128-131.

The fine structure of the body wall and gut was for the first time studied in the competent larvae of the frenulate pogonophoran Siboglinum fiordicum. Mass apoptosis of cell nuclei was observed in the dermo-muscular body wall and coelomic epithelium. Apoptotic nuclei were found in both cell cytoplasm and outside of the larval body. In the latter case, each nucleus was surrounded by the plasmalemma, and the entire cluster was covered with the cuticle. Cells of the larval gut retained the usual structure with the cytoplasm filled with numerous yolky granules and the nucleus displaying usual morphology. Similar apoptotic processes have been described in vestimentiferans and found to be initiated by penetration of symbiotic bacteria through the integument into the dorsal mesentery. The process of apoptotic rearrangement of body wall cells and the formation of unique symbiosis with bacteria were assumed to be time-spaced in S. fiordicum, occurring sequentially rather than simultaneously, unlike in vestimentiferans.

RevDate: 2022-10-27

Ganesan R, Wierz JC, Kaltenpoth M, et al (2022)

How It All Begins: Bacterial Factors Mediating the Colonization of Invertebrate Hosts by Beneficial Symbionts.

Microbiology and molecular biology reviews : MMBR [Epub ahead of print].

Beneficial associations with bacteria are widespread across animals, spanning a range of symbiont localizations, transmission routes, and functions. While some of these associations have evolved into obligate relationships with permanent symbiont localization within the host, the majority require colonization of every host generation from the environment or via maternal provisions. Across the broad diversity of host species and tissue types that beneficial bacteria can colonize, there are some highly specialized strategies for establishment yet also some common patterns in the molecular basis of colonization. This review focuses on the mechanisms underlying the early stage of beneficial bacterium-invertebrate associations, from initial contact to the establishment of the symbionts in a specific location of the host's body. We first reflect on general selective pressures that can drive the transition from a free-living to a host-associated lifestyle in bacteria. We then cover bacterial molecular factors for colonization in symbioses from both model and nonmodel invertebrate systems where these have been studied, including terrestrial and aquatic host taxa. Finally, we discuss how interactions between multiple colonizing bacteria and priority effects can influence colonization. Taking the bacterial perspective, we emphasize the importance of developing new experimentally tractable systems to derive general insights into the ecological factors and molecular adaptations underlying the origin and establishment of beneficial symbioses in animals.

RevDate: 2022-10-27

Cao CTH, Derbyshire MC, Regmi R, et al (2022)

Small RNA Analyses of a Ceratobasidium Isolate Infected with Three Endornaviruses.

Viruses, 14(10): pii:v14102276.

Isolates of three endornavirus species were identified co-infecting an unidentified species of Ceratobasidium, itself identified as a symbiont from within the roots of a wild plant of the terrestrial orchid Pterostylis vittata in Western Australia. Isogenic lines of the fungal isolate lacking all three mycoviruses were derived from the virus-infected isolate. To observe how presence of endornaviruses influenced gene expression in the fungal host, we sequenced fungus-derived small RNA species from the virus-infected and virus-free isogenic lines and compared them. The presence of mycoviruses influenced expression of small RNAs. Of the 3272 fungus-derived small RNA species identified, the expression of 9.1% (300 of 3272) of them were up-regulated, and 0.6% (18 of 3272) were down-regulated in the presence of the viruses. Fourteen novel micro-RNA-like RNAs (Cer-milRNAs) were predicted. Gene target prediction of the differentially expressed Cer-milRNAs was quite ambiguous; however, fungal genes involved in transcriptional regulation, catalysis, molecular binding, and metabolic activities such as gene expression, DNA metabolic processes and regulation activities were differentially expressed in the presence of the mycoviruses.

RevDate: 2022-10-27

Rathod M, Dalvi C, Kaur K, et al (2022)

Kids' Emotion Recognition Using Various Deep-Learning Models with Explainable AI.

Sensors (Basel, Switzerland), 22(20): pii:s22208066.

Human ideas and sentiments are mirrored in facial expressions. They give the spectator a plethora of social cues, such as the viewer's focus of attention, intention, motivation, and mood, which can help develop better interactive solutions in online platforms. This could be helpful for children while teaching them, which could help in cultivating a better interactive connect between teachers and students, since there is an increasing trend toward the online education platform due to the COVID-19 pandemic. To solve this, the authors proposed kids' emotion recognition based on visual cues in this research with a justified reasoning model of explainable AI. The authors used two datasets to work on this problem; the first is the LIRIS Children Spontaneous Facial Expression Video Database, and the second is an author-created novel dataset of emotions displayed by children aged 7 to 10. The authors identified that the LIRIS dataset has achieved only 75% accuracy, and no study has worked further on this dataset in which the authors have achieved the highest accuracy of 89.31% and, in the authors' dataset, an accuracy of 90.98%. The authors also realized that the face construction of children and adults is different, and the way children show emotions is very different and does not always follow the same way of facial expression for a specific emotion as compared with adults. Hence, the authors used 3D 468 landmark points and created two separate versions of the dataset from the original selected datasets, which are LIRIS-Mesh and Authors-Mesh. In total, all four types of datasets were used, namely LIRIS, the authors' dataset, LIRIS-Mesh, and Authors-Mesh, and a comparative analysis was performed by using seven different CNN models. The authors not only compared all dataset types used on different CNN models but also explained for every type of CNN used on every specific dataset type how test images are perceived by the deep-learning models by using explainable artificial intelligence (XAI), which helps in localizing features contributing to particular emotions. The authors used three methods of XAI, namely Grad-CAM, Grad-CAM++, and SoftGrad, which help users further establish the appropriate reason for emotion detection by knowing the contribution of its features in it.

RevDate: 2022-10-27

Yan T, Zhang P, Pang W, et al (2022)

Effects of High Temperature-Triggered Transcriptomics on the Physiological Adaptability of Cenococcum geophilum, an Ectomycorrhizal Fungus.

Microorganisms, 10(10): pii:microorganisms10102039.

High temperature stress caused by global warming presents a challenge to the healthy development of forestry. Cenococcum geophilum is a common ectomycorrhizal fungus (ECMF) in the forest system and has become an important fungus resource with application potential in forest vegetation restoration. In this study, three sensitive isolates of C. geophilum (ChCg01, JaCg144 and JaCg202) and three tolerant isolates of C. geophilum (ACg07, ChCg28 and ChCg100) were used to analyze the physiological and molecular responses to high temperature. The results showed that high temperature had a significant negative effect on the growth of sensitive isolates while promoting the growth of tolerant isolates. The antioxidative enzymes activity of C. geophilum isolates increased under high temperature stress, and the SOD activity of tolerant isolates (A07Cg and ChCg100) was higher than that of sensitive isolates (ChCg01 and JaCg202) significantly. The tolerant isolates secreted more succinate, while the sensitive isolates secreted more oxalic acid under high temperature stress. Comparative transcriptomic analysis showed that differentially expressed genes (DEGs) of six C. geophilum isolates were significantly enriched in "antioxidant" GO entry in the molecular. In addition, the "ABC transporters" pathway and the "glyoxylate and dicarboxylic acid metabolic" were shared in the three tolerant isolates and the three sensitive isolates, respectively. These results were further verified by RT-qPCR analysis. In conclusion, our findings suggest that C. geophilum can affect the organic acid secretion and increase antioxidant enzyme activity in response to high temperature by upregulating related genes.

RevDate: 2022-10-27

Caruso DJ, Palombo EA, Moulton SE, et al (2022)

Exploring the Promise of Endophytic Fungi: A Review of Novel Antimicrobial Compounds.

Microorganisms, 10(10): pii:microorganisms10101990.

Over the last few decades, many of the existing drugs used to treat infectious diseases have become increasingly ineffective due to the global emergence of antimicrobial resistance (AMR). As such, there is a constant demand to find new, effective compounds that could help to alleviate some of this pressure. Endophytic fungi have captured the attention of many researchers in this field, as they have displayed a vast ability to produce novel bioactive compounds, many of which possess wide-ranging antimicrobial activities. However, while highly promising, research in this area is still in its infancy. Endophytes inhabit the healthy tissues of plants asymptomatically, resulting in a mutualistic symbiosis in which the endophytes produce a plethora of bioactive compounds that support the fitness of the host plant. These compounds display great chemical diversity, representing structural groups, such as aliphatic compounds, alkaloids, peptides, phenolics, polyketides and terpenoids. In this review, the significant antimicrobial potential of endophytic fungi is detailed, highlighting their ability to produce novel and diverse antimicrobial compounds active against human, plant and marine pathogens. In doing so, it also highlights the significant contributions that endophytic fungi can make in our battle against AMR, thus providing the motivation to increase efforts in the search for new and effective antimicrobial drugs.

RevDate: 2022-10-27

Soto W (2022)

Emerging Research Topics in the Vibrionaceae and the Squid-Vibrio Symbiosis.

Microorganisms, 10(10): pii:microorganisms10101946.

The Vibrionaceae encompasses a cosmopolitan group that is mostly aquatic and possesses tremendous metabolic and genetic diversity. Given the importance of this taxon, it deserves continued and deeper research in a multitude of areas. This review outlines emerging topics of interest within the Vibrionaceae. Moreover, previously understudied research areas are highlighted that merit further exploration, including affiliations with marine plants (seagrasses), microbial predators, intracellular niches, and resistance to heavy metal toxicity. Agarases, phototrophy, phage shock protein response, and microbial experimental evolution are also fields discussed. The squid-Vibrio symbiosis is a stellar model system, which can be a useful guiding light on deeper expeditions and voyages traversing these "seas of interest". Where appropriate, the squid-Vibrio mutualism is mentioned in how it has or could facilitate the illumination of these various subjects. Additional research is warranted on the topics specified herein, since they have critical relevance for biomedical science, pharmaceuticals, and health care. There are also practical applications in agriculture, zymology, food science, and culinary use. The tractability of microbial experimental evolution is explained. Examples are given of how microbial selection studies can be used to examine the roles of chance, contingency, and determinism (natural selection) in shaping Earth's natural history.

RevDate: 2022-10-27

Jiang ZR, Morita T, Jikumaru S, et al (2022)

The Role of Mycangial Fungi Associated with Ambrosia Beetles (Euwallacea interjectus) in Fig Wilt Disease: Dual Inoculation of Fusarium kuroshium and Ceratocystis ficicola Can Bring Fig Saplings to Early Symptom Development.

Microorganisms, 10(10): pii:microorganisms10101912.

The ambrosia beetle, Euwallacea interjectus, is a wood-boring pest and a vector of Ceratocystis ficicola, a pathogenic fungus causing fig (Ficus carica) wilt disease (FWD) in Japan. The ambrosia fungi, Fusarium kuroshium and Neocosmospora metavorans, have been frequently isolated from heads (including mycangia) of wild and reared adult female E. interjectus, respectively. However, the exact mechanisms driving FWD as well as the interactions between F. kuroshium and C. ficicola in fig orchard remain unclear. To verify the role of the mycangial fungi in the FWD progression, fig saplings were subjected to inoculation treatments (T1, F. kuroshium; T2, N. metavorans, reference positive control; T3, C. ficicola; T4, F. kuroshium + C. ficicola, realistic on-site combination). T3 and T4 saplings began wilting approximately 12 days after inoculation, leading to eventual death. Median duration from inoculation to death of the T4 saplings was approximately four days significantly faster than that of the T3 saplings. Xylem sap-conduction test indicated that dysfunction and necrosis area were considerably wider in the T4 saplings than in T3 saplings. These results demonstrate that the synergistic action of F. kuroshium and C. ficicola contributed to accelerated wilting in the saplings. Based on these discoveries, we proposed a model for system changes in the symbiosis between E. interjectus and its associated fungi in FWD in Japan.

RevDate: 2022-10-27

Basiru S, M Hijri (2022)

The Potential Applications of Commercial Arbuscular Mycorrhizal Fungal Inoculants and Their Ecological Consequences.

Microorganisms, 10(10): pii:microorganisms10101897.

Arbuscular mycorrhizal fungal (AMF) inoculants are sustainable biological materials that can provide several benefits to plants, especially in disturbed agroecosystems and in the context of phytomanagement interventions. However, it is difficult to predict the effectiveness of AMF inoculants and their impacts on indigenous AMF communities under field conditions. In this review, we examined the literature on the possible outcomes following the introduction of AMF-based inoculants in the field, including their establishment in soil and plant roots, persistence, and effects on the indigenous AMF community. Most studies indicate that introduced AMF can persist in the target field from a few months to several years but with declining abundance (60%) or complete exclusion (30%). Further analysis shows that AMF inoculation exerts both positive and negative impacts on native AMF species, including suppression (33%), stimulation (38%), exclusion (19%), and neutral impacts (10% of examined cases). The factors influencing the ecological fates of AMF inoculants, such as the inherent properties of the inoculum, dosage and frequency of inoculation, and soil physical and biological factors, are further discussed. While it is important to monitor the success and downstream impacts of commercial inoculants in the field, the sampling method and the molecular tools employed to resolve and quantify AMF taxa need to be improved and standardized to eliminate bias towards certain AMF strains and reduce discrepancies among studies. Lastly, inoculant producers must focus on selecting strains with a higher chance of success in the field, and having little or negligible downstream impacts.

RevDate: 2022-10-27

Fardella PA, Tian Z, Clarke BB, et al (2022)

The Epichloë festucae Antifungal Protein Efe-AfpA Protects Creeping Bentgrass (Agrostis stolonifera) from the Plant Pathogen Clarireedia jacksonii, the Causal Agent of Dollar Spot Disease.

Journal of fungi (Basel, Switzerland), 8(10): pii:jof8101097.

Dollar spot disease, caused by the fungal pathogen Clarireedia jacksonii, is a major problem in many turfgrass species, particularly creeping bentgrass (Agrostis stolonifera). It is well-established that strong creeping red fescue (Festuca rubra subsp. rubra) exhibits good dollar spot resistance when infected by the fungal endophyte Epichloë&nbsp;festucae. This endophyte-mediated disease resistance is unique to the fine fescues and has not been observed in other grass species infected with other Epichloë spp. The mechanism underlying the unique endophyte-mediated disease resistance in strong creeping red fescue has not yet been established. We pursued the possibility that it may be due to the presence of an abundant secreted antifungal protein produced by E. festucae. Here, we compare the activity of the antifungal protein expressed in Escherichia coli, Pichia pastoris, and Penicillium chrysogenum. Active protein was recovered from all systems, with the best activity being from Pe. chrysogenum. In greenhouse assays, topical application of the purified antifungal protein to creeping bentgrass and endophyte-free strong creeping red fescue protected the plants from developing severe symptoms caused by C. jacksonii. These results support the hypothesis that Efe-AfpA is a major contributor to the dollar spot resistance observed with E. festucae-infected strong creeping red fescue in the field, and that this protein could be developed as an alternative or complement to fungicides for the management of this disease on turfgrasses.

RevDate: 2022-10-27

Satish L, Barak H, Keren G, et al (2022)

The Microbiome Structure of the Symbiosis between the Desert Truffle Terfezia boudieri and Its Host Plant Helianthemum sessiliflorum.

Journal of fungi (Basel, Switzerland), 8(10): pii:jof8101062.

The desert truffle Terfezia boudieri is an ascomycete fungus that forms ect-endomycorrhiza in the roots of plants belonging to Cistaceae. The fungus forms hypogeous edible fruit bodies, appreciated as gourmet food. Truffles and host plants are colonized by various microbes, which may contribute to their development. However, the diversity and composition of the bacterial community under field conditions in the Negev desert are still unknown. The overall goal of this research was to identify the rhizosphere microbial community supporting the establishment of a symbiotic association between T. boudieri and Helianthemum sessiliflorum. The bacterial community was characterized by fruiting bodies, mycorrhized roots, and rhizosphere soil. Based on next-generation sequencing meta-analyses of the 16S rRNA gene, we discovered diverse bacterial communities of fruit bodies that differed from those found in the roots and rhizosphere. Families of Proteobacteria, Planctomycetes, and Actinobacteria were present in all four samples. Alpha diversity analysis revealed that the rhizosphere and roots contain significantly higher bacterial species numbers compared to the fruit. Additionally, ANOSIM and PCoA provided a comparative analysis of the bacterial taxa associated with fruiting bodies, roots, and rhizosphere. The core microbiome described consists of groups whose biological role triggers important traits supporting plant growth and fruit body development.

RevDate: 2022-10-27

Loth K, Parisot N, Paquet F, et al (2022)

Aphid BCR4 Structure and Activity Uncover a New Defensin Peptide Superfamily.

International journal of molecular sciences, 23(20): pii:ijms232012480.

Aphids (Hemiptera: Aphidoidea) are among the most detrimental insects for agricultural plants, and their management is a great challenge in agronomical research. A new class of proteins, called Bacteriocyte-specific Cysteine-Rich (BCR) peptides, provides an alternative to chemical insecticides for pest control. BCRs were initially identified in the pea aphid Acyrthosiphon pisum. They are small disulfide bond-rich proteins expressed exclusively in aphid bacteriocytes, the insect cells that host intracellular symbiotic bacteria. Here, we show that one of the A. pisum BCRs, BCR4, displays prominent insecticidal activity against the pea aphid, impairing insect survival and nymphal growth, providing evidence for its potential use as a new biopesticide. Our comparative genomics and phylogenetic analyses indicate that BCRs are restricted to the aphid lineage. The 3D structure of BCR4 reveals that this peptide belongs to an as-yet-unknown structural class of peptides and defines a new superfamily of defensins.

RevDate: 2022-10-27

Huang R, Li Z, Shen X, et al (2022)

The Perspective of Arbuscular Mycorrhizal Symbiosis in Rice Domestication and Breeding.

International journal of molecular sciences, 23(20): pii:ijms232012383.

In nature, symbiosis with arbuscular mycorrhizal (AM) fungi contributes to sustainable acquisition of phosphorus and other elements in over 80% of plant species; improving interactions with AM symbionts may mitigate some of the environmental problems associated with fertilizer application in grain crops such as rice. Recent developments of high-throughput genome sequencing projects of thousands of rice cultivars and the discovery of the molecular mechanisms underlying AM symbiosis suggest that interactions with AM fungi might have been an overlooked critical trait in rice domestication and breeding. In this review, we discuss genetic variation in the ability of rice to form AM symbioses and how this might have affected rice domestication. Finally, we discuss potential applications of AM symbiosis in rice breeding for more sustainable agriculture.

RevDate: 2022-10-27

Li M, Chen Q, Wu C, et al (2022)

A Novel Module Promotes Horizontal Gene Transfer in Azorhizobium caulinodans ORS571.

Genes, 13(10): pii:genes13101895.

Azorhizobium caulinodans ORS571 contains an 87.6 kb integrative and conjugative element (ICEAc) that conjugatively transfers symbiosis genes to other rhizobia. Many hypothetical redundant gene fragments (rgfs) are abundant in ICEAc, but their potential function in horizontal gene transfer (HGT) is unknown. Molecular biological methods were employed to delete hypothetical rgfs, expecting to acquire a minimal ICEAc and consider non-functional rgfs as editable regions for inserting genes related to new symbiotic functions. We determined the significance of rgf4 in HGT and identified the physiological function of genes designated rihF1a (AZC_3879), rihF1b (AZC_RS26200), and rihR (AZC_3881). In-frame deletion and complementation assays revealed that rihF1a and rihF1b work as a unit (rihF1) that positively affects HGT frequency. The EMSA assay and lacZ-based reporter system showed that the XRE-family protein RihR is not a regulator of rihF1 but promotes the expression of the integrase (intC) that has been reported to be upregulated by the LysR-family protein, AhaR, through sensing host's flavonoid. Overall, a conservative module containing rihF1 and rihR was characterized, eliminating the size of ICEAc by 18.5%. We propose the feasibility of constructing a minimal ICEAc element to facilitate the exchange of new genetic components essential for symbiosis or other metabolic functions between soil bacteria.

RevDate: 2022-10-27

Wang L, Zhang S, Fang J, et al (2022)

The Chloroplast Genome of the Lichen Photobiont Trebouxiophyceae sp. DW1 and Its Phylogenetic Implications.

Genes, 13(10): pii:genes13101840.

Lichens are symbiotic associations of algae and fungi. The genetic mechanism of the symbiosis of lichens and the influence of symbiosis on the size and composition of the genomes of symbiotic algae have always been intriguing scientific questions explored by lichenologists. However, there were limited data on lichen genomes. Therefore, we isolated and purified a lichen symbiotic alga to obtain a single strain (Trebouxiophyceae sp. DW1), and then obtained its chloroplast genome information by next-generation sequencing (NGS). The chloroplast genome is 129,447 bp in length, and the GC content is 35.2%. Repetitive sequences with the length of 30-35 bp account for 1.27% of the total chloroplast genome. The simple sequence repeats are all mononucleotide repeats. Codon usage analysis showed that the genome tended to use codon ending in A/U. By comparing the length of different regions of Trebouxiophyceae genomes, we found that the changes in the length of exons, introns, and intergenic sequences affect the size of genomes. Trebouxiophyceae had an unstable chloroplast genome structure, with IRs repeatedly losing during evolution. Phylogenetic analysis showed that Trebouxiophyceae is paraphyletic, and Trebouxiophyceae sp. DW1 is sister to the clade of Koliella longiseta and Pabia signiensis.

RevDate: 2022-10-27

Jadhav S, Makar P, V Nema (2022)

The NeuroinflammatoryPotential of HIV-1 NefVariants in Modulating the Gene Expression Profile of Astrocytes.

Cells, 11(20): pii:cells11203256.

HIV-1 mediated neurotoxicity is thought to be associated with HIV-1 viral proteins activating astrocytes and microglia by inducing inflammatory cytokines leading to the development of HIV-associated neurocognitive disorder (HAND). In the current study, we observe how HIV-1 Nef upregulates the levels of IL-6, IP-10, and TNF-α around 6.0fold in normal human astrocytes (NHAs) compared to cell and empty vector controls. Moderate downregulation in the expression profile of inflammatory cytokines was observed due to RNA interference. Furthermore, we determine the impact of inflammatory cytokines in the upregulation of kynurenine pathway metabolites, such as indoleamine 2,3-dioxygenase (IDO), and 3-hydroxyanthranilic acid oxygenase (HAAO) in NHA, and found the same to be 3.0- and 3.2-fold, respectively. Additionally, the variation in the level of nitric oxide before and after RNA interference was significant. The upregulated cytokines and pathway-specific metabolites could be linked with the neurotoxic potential of HIV-1 Nef. Thus, the downregulation in cytokines and kynurenine metabolites observed after siRNA-Nef interference indicates the possibility of combining the RNA interference approach with current antiretroviral therapy to prevent neurotoxicity development.

RevDate: 2022-10-27

Durge A, Sharma I, RS Tupe (2022)

Glycation-Associated Diabetic Nephropathy and the Role of Long Noncoding RNAs.

Biomedicines, 10(10): pii:biomedicines10102623.

The glycation of various biomolecules is the root cause of many pathological conditions associated with diabetic nephropathy and end-stage kidney disease. Glycation imbalances metabolism and increases renal cell injury. Numerous therapeutic measures have narrowed down the adverse effects of endogenous glycation, but efficient and potent measures are miles away. Recent advances in the identification and characterization of noncoding RNAs, especially the long noncoding RNAs (lncRNAs), have opened a mammon of new biology to explore the mitigations for glycation-associated diabetic nephropathy. Furthermore, tissue-specific distribution and condition-specific expression make lncRNA a promising key for second-generation therapeutic interventions. Though the techniques to identify and exemplify noncoding RNAs are rapidly evolving, the lncRNA study encounters multiple methodological constraints. This review will discuss lncRNAs and their possible involvement in glycation and advanced glycation end products (AGEs) signaling pathways. We further highlight the possible approaches for lncRNA-based therapeutics and their working mechanism for perturbing glycation and conclude our review with lncRNAs biology-related future opportunities.


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 )