Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 19.070
Filtrar
1.
Sci Total Environ ; 750: 141439, 2021 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-32882488

RESUMO

Certain lichens are effective colonisers of polluted sites. However, little is known about the tolerance of photobionts and the degree of mycobiont selectivity to photobionts relative to metal pollution. The present study recognises the genetic and anatomical diversity of Asterochloris photobionts in epigeic lichens, i.e. Cladonia cariosa, C. rei, and Diploschistes muscorum, in relation to a wide spectrum of soil pollution. In accordance with phylogenetic analysis, photobionts were clustered in 7 moderately- to well-supported clades, including 19 haplotypes. The mycobionts of all studied lichens demonstrated a low level of selectivity and were capable of associating with various Asterochloris lineages. This tendency was also expressed by the frequent (~25%) occurrence of multiple algal genotypes in a single thallus. This indicates that identified Asterochloris lineages are generally tolerant to heavy-metal pollution, and the low level of selectivity of mycobionts enables them to select the most suitable and/or available partner. The trend of increasing incidence of certain Asterochloris lineages and decreasing frequency of others along with increasing soil pollution was observed. This proves the superior adaptation of some photobionts to polluted sites. Such symbiotic plasticity constitute an adaptive feature necessary for the successful colonisation. High number of haplotypes at polluted sites could be the result of multiple introduction events from different areas during the initial stages of spontaneous succession. Regardless of the genetic pattern, Asterochloris cells were considerably smaller, and the density and compaction of cells in the algal layer were higher, in lichen specimens from polluted sites, indicating that photobiont characteristics may be closely dependent on heavy-metal pollution.


Assuntos
Líquens , Metais Pesados , Ecossistema , Poluição Ambiental , Filogenia , Simbiose
2.
Nat Commun ; 11(1): 5470, 2020 10 29.
Artigo em Inglês | MEDLINE | ID: mdl-33122629

RESUMO

Mutualistic networks are vital ecological and social systems shaped by adaptation and evolution. They involve bipartite cooperation via the exchange of goods or services between actors of different types. Empirical observations of mutualistic networks across genres and geographic conditions reveal correlated nested and modular patterns. Yet, the underlying mechanism for the network assembly remains unclear. We propose a niche-based adaptive mechanism where both nestedness and modularity emerge simultaneously as complementary facets of an optimal niche structure. Key dynamical properties are revealed at different timescales. Foremost, mutualism can either enhance or reduce the network stability, depending on competition intensity. Moreover, structural adaptations are asymmetric, exhibiting strong hysteresis in response to environmental change. Finally, at the evolutionary timescale we show that the adaptive mechanism plays a crucial role in preserving the distinctive patterns of mutualism under species invasions and extinctions.


Assuntos
Ecologia/métodos , Cadeia Alimentar , Modelos Teóricos , Simbiose , Animais , Evolução Biológica , Biologia Computacional , Ecossistema
3.
PLoS One ; 15(10): e0235446, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33002000

RESUMO

We recently described a regulatory loop, which we termed autoregulation of infection (AOI), by which Sinorhizobium meliloti, a Medicago endosymbiont, downregulates the root susceptibility to secondary infection events via ethylene. AOI is initially triggered by so-far unidentified Medicago nodule signals named signal 1 and signal 1' whose transduction in bacteroids requires the S. meliloti outer-membrane-associated NsrA receptor protein and the cognate inner-membrane-associated adenylate cyclases, CyaK and CyaD1/D2, respectively. Here, we report on advances in signal 1 identification. Signal 1 activity is widespread as we robustly detected it in Medicago nodule extracts as well as in yeast and bacteria cell extracts. Biochemical analyses indicated a peptidic nature for signal 1 and, together with proteomic analyses, a universally conserved Medicago ribosomal protein of the uL2 family was identified as a candidate signal 1. Specifically, MtRPuL2A (MtrunA17Chr7g0247311) displays a strong signal activity that requires S. meliloti NsrA and CyaK, as endogenous signal 1. We have shown that MtRPuL2A is active in signaling only in a non-ribosomal form. A Medicago truncatula mutant in the major symbiotic transcriptional regulator MtNF-YA1 lacked most signal 1 activity, suggesting that signal 1 is under developmental control. Altogether, our results point to the MtRPuL2A ribosomal protein as the candidate for signal 1. Based on the Mtnf-ya1 mutant, we suggest a link between root infectiveness and nodule development. We discuss our findings in the context of ribosomal protein moonlighting.


Assuntos
Medicago truncatula , Proteínas de Plantas/metabolismo , Proteínas Ribossômicas/metabolismo , Nódulos Radiculares de Plantas/metabolismo , Sinorhizobium meliloti/metabolismo , Coinfecção/prevenção & controle , Etilenos/metabolismo , Regulação da Expressão Gênica de Plantas , Genes de Plantas , Medicago truncatula/genética , Medicago truncatula/metabolismo , Medicago truncatula/microbiologia , Imunidade Vegetal/genética , Proteínas de Plantas/genética , Nodulação/fisiologia , Raízes de Plantas/metabolismo , Raízes de Plantas/microbiologia , Proteínas Ribossômicas/genética , Nódulos Radiculares de Plantas/microbiologia , Transdução de Sinais , Simbiose
4.
PLoS One ; 15(10): e0227161, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33052936

RESUMO

Dispersal of whitebark pine (Pinus albicaulis Engelm.), a keystone species of many high-elevation ecosystems in western North America, depends on Clark's nutcracker (Nucifraga columbiana Wilson), a seed-caching bird with an affinity for whitebark seeds. To the extent that this dependence is mutual, declines in whitebark seed production could cause declines in nutcracker abundance. Whitebark pine is in decline across much of its range due to interacting stressors, including the non-native pathogen white pine blister rust (Cronartium ribicola J. C. Fisch.). We used avian point-count data and tree surveys from four national park units to investigate whether trends in whitebark pine can explain trends in Clark's nutcracker. Spatial trends were modeled using recent data from two parks, while temporal trends were modeled using longer time-series of nutcracker and whitebark data from two additional parks. To assess the potential dependence of nutcrackers on whitebark, we linked a model of nutcracker density (accounting for detection probability) with a model of whitebark trends, using a Bayesian framework to translate uncertainty in whitebark metrics to uncertainty in nutcracker density. In Mount Rainier National Park, temporal models showed dramatic declines in nutcracker density concurrent with significant increases in whitebark crown mortality and trees infected with white pine blister rust. However, nutcrackers did not trend with whitebark metrics in North Cascades National Park Service Complex. In spatial models of data from Yosemite National Park and Sequoia-Kings Canyon National Park, nutcracker density varied not only with local cover of whitebark but also with elevation and, in Sequoia-Kings Canyon, with cover of another species of white pine. Our results add support for the hypothesis that the mutualism between whitebark pine and Clark's nutcracker is vulnerable to disruption by blister rust, and our approach integrates data across monitoring programs to explore trends in species interactions.


Assuntos
Passeriformes/crescimento & desenvolvimento , Pinus/crescimento & desenvolvimento , Animais , Teorema de Bayes , América do Norte , Parques Recreativos , Densidade Demográfica , Dinâmica Populacional , Análise Espaço-Temporal , Simbiose
5.
PLoS One ; 15(10): e0228514, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33091033

RESUMO

Coral disease outbreaks are expected to increase in prevalence, frequency and severity due to climate change and other anthropogenic stressors. This is especially worrying for the Caribbean branching coral Acropora palmata which has already seen an 80% decrease in cover primarily due to disease. Despite the importance of this keystone species, there has yet to be a characterization of its transcriptomic response to disease exposure. In this study we provide the first transcriptomic analysis of 12 A. palmata genotypes and their symbiont Symbiodiniaceae exposed to disease in 2016 and 2017. Year was the primary driver of gene expression variance for A. palmata and the Symbiodiniaceae. We hypothesize that lower expression of ribosomal genes in the coral, and higher expression of transmembrane ion transport genes in the Symbiodiniaceae indicate that a compensation or dysbiosis may be occurring between host and symbiont. Disease response was the second driver of gene expression variance for A. palmata and included a core set of 422 genes that were significantly differentially expressed. Of these, 2 genes (a predicted cyclin-dependent kinase 11b and aspartate 1-decarboxylase) showed negative Log2 fold changes in corals showing transmission of disease, and positive Log2 fold changes in corals showing no transmission of disease, indicating that these may be important in disease resistance. Co-expression analysis identified two modules positively correlated to disease exposure, one enriched for lipid biosynthesis genes, and the other enriched in innate immune genes. The hub gene in the immune module was identified as D-amino acid oxidase, a gene implicated in phagocytosis and microbiome homeostasis. The role of D-amino acid oxidase in coral immunity has not been characterized but could be an important enzyme for responding to disease. Our results indicate that A. palmata mounts a core immune response to disease exposure despite differences in the disease type and virulence between 2016 and 2017. These identified genes may be important for future biomarker development in this Caribbean keystone species.


Assuntos
Alveolados/genética , Antozoários/parasitologia , Perfilação da Expressão Gênica/veterinária , Imunidade Inata , Animais , Antozoários/genética , Antozoários/imunologia , Mudança Climática , Regulação da Expressão Gênica , Genótipo , Proteínas de Protozoários/genética , Proteínas Ribossômicas/genética , Simbiose
6.
Molecules ; 25(21)2020 Oct 22.
Artigo em Inglês | MEDLINE | ID: mdl-33105830

RESUMO

Inflammation is a biological response to the activation of the immune system by various infectious or non-infectious agents, which may lead to tissue damage and various diseases. Gut commensal bacteria maintain a symbiotic relationship with the host and display a critical function in the homeostasis of the host immune system. Disturbance to the gut microbiota leads to immune dysfunction both locally and at distant sites, which causes inflammatory conditions not only in the intestine but also in the other organs such as lungs and brain, and may induce a disease state. Probiotics are well known to reinforce immunity and counteract inflammation by restoring symbiosis within the gut microbiota. As a result, probiotics protect against various diseases, including respiratory infections and neuroinflammatory disorders. A growing body of research supports the beneficial role of probiotics in lung and mental health through modulating the gut-lung and gut-brain axes. In the current paper, we discuss the potential role of probiotics in the treatment of viral respiratory infections, including the COVID-19 disease, as major public health crisis in 2020, and influenza virus infection, as well as treatment of neurological disorders like multiple sclerosis and other mental illnesses.


Assuntos
Infecções por Coronavirus/terapia , Influenza Humana/terapia , Transtornos Mentais/terapia , Esclerose Múltipla/terapia , Pneumonia Viral/terapia , Probióticos/uso terapêutico , Infecções Respiratórias/terapia , Betacoronavirus/efeitos dos fármacos , Betacoronavirus/patogenicidade , Betacoronavirus/fisiologia , Encéfalo/imunologia , Infecções por Coronavirus/imunologia , Infecções por Coronavirus/microbiologia , Infecções por Coronavirus/virologia , Microbioma Gastrointestinal/imunologia , Trato Gastrointestinal/imunologia , Trato Gastrointestinal/microbiologia , Humanos , Imunomodulação , Influenza Humana/imunologia , Influenza Humana/microbiologia , Influenza Humana/virologia , Pulmão/imunologia , Transtornos Mentais/imunologia , Transtornos Mentais/microbiologia , Consórcios Microbianos/imunologia , Esclerose Múltipla/imunologia , Esclerose Múltipla/microbiologia , Orthomyxoviridae/efeitos dos fármacos , Orthomyxoviridae/patogenicidade , Orthomyxoviridae/fisiologia , Pandemias , Pneumonia Viral/imunologia , Pneumonia Viral/microbiologia , Pneumonia Viral/virologia , Infecções Respiratórias/imunologia , Infecções Respiratórias/microbiologia , Simbiose/imunologia
7.
Nat Commun ; 11(1): 5125, 2020 10 12.
Artigo em Inglês | MEDLINE | ID: mdl-33046698

RESUMO

Mycorrhizal fungi are mutualists that play crucial roles in nutrient acquisition in terrestrial ecosystems. Mycorrhizal symbioses arose repeatedly across multiple lineages of Mucoromycotina, Ascomycota, and Basidiomycota. Considerable variation exists in the capacity of mycorrhizal fungi to acquire carbon from soil organic matter. Here, we present a combined analysis of 135 fungal genomes from 73 saprotrophic, endophytic and pathogenic species, and 62 mycorrhizal species, including 29 new mycorrhizal genomes. This study samples ecologically dominant fungal guilds for which there were previously no symbiotic genomes available, including ectomycorrhizal Russulales, Thelephorales and Cantharellales. Our analyses show that transitions from saprotrophy to symbiosis involve (1) widespread losses of degrading enzymes acting on lignin and cellulose, (2) co-option of genes present in saprotrophic ancestors to fulfill new symbiotic functions, (3) diversification of novel, lineage-specific symbiosis-induced genes, (4) proliferation of transposable elements and (5) divergent genetic innovations underlying the convergent origins of the ectomycorrhizal guild.


Assuntos
Fungos/genética , Genoma Fúngico , Micorrizas/genética , Simbiose , Ecossistema , Evolução Molecular , Proteínas Fúngicas/genética , Fungos/classificação , Fungos/fisiologia , Micorrizas/classificação , Micorrizas/fisiologia , Filogenia , Fenômenos Fisiológicos Vegetais , Plantas/microbiologia
8.
BMC Ecol ; 20(1): 56, 2020 10 15.
Artigo em Inglês | MEDLINE | ID: mdl-33059667

RESUMO

BACKGROUND: Landscape genetics is an interdisciplinary field that combines tools and techniques from population genetics with the spatially explicit principles from landscape ecology. Spatial variation in genotypes is used to test hypotheses about how landscape pattern affects dispersal in a wide range of taxa. Lichens, symbiotic associations between mycobionts and photobionts, are an entity for which little is known about their dispersal mechanism. Our objective was to infer the dispersal mechanism in the semi-aquatic lichen Dermatocarpon luridum using spatial models and the spatial variation of the photobiont, Diplosphaera chodatii. We sequenced the ITS rDNA and the ß-actin gene regions of the photobiont and mapped the haplotype spatial distribution in Payuk Lake. We subdivided Payuk Lake into subpopulations and applied four spatial models based on the topography and hydrology to infer the dispersal mechanism. RESULTS: Genetic variation corresponded with the topography of the lake and the net flow of water through the waterbody. A lack of isolation-by-distance suggests high gene flow or dispersal within the lake. We infer the dispersal mechanism in D. luridum could either be by wind and/or water based on the haplotype spatial distribution of its photobiont using the ITS rDNA and ß-actin markers. CONCLUSIONS: We inferred that the dispersal mechanism could be either wind and/or water dispersed due to the conflicting interpretations of our landscape hypotheses. This is the first study to use spatial modelling to infer dispersal in semi-aquatic lichens. The results of this study may help to understand lichen dispersal within aquatic landscapes, which can have implications in the conservation of rare or threatened lichens.


Assuntos
Líquens , Fluxo Gênico , Genética Populacional , Genótipo , Líquens/genética , Simbiose
9.
J Environ Qual ; 49(4): 987-999, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-33016489

RESUMO

The soil fluorine (F) concentration in New Zealand agricultural soils has increased with time as a direct result of the widespread application of phosphate fertilizer to land. Elevated soil F concentrations may potentially harm soil microorganisms, which are important for nutrient cycling and soil formation. Rhizobium leguminosarum is a N2 -fixing soil bacterium that is a fundamental component in New Zealand legume-based pastoral farming. Any impact of F on Rhizobium leguminosarum would have an adverse effect on New Zealand pasture production. In this study, F toxicity to Rhizobium leguminosarum was examined as a first step to develop F guideline values for New Zealand agricultural soils. Bottle-based experiments were conducted to examine the effect of the F- ion on Rhizobium-white clover (Trifolium repens L.) symbiosis by observing nodule morphology and growth. Results indicate that the F- concentration that causes 10% inhibition of Rhizobium respiration (IC10 ) for F- toxicity to Rhizobium leguminosarum was >100 mg F-  L-1 . Significant morphological changes occurred when Rhizobium was exposed to F concentrations of 500 and 1000 mg L-1 . Both light and transmission electron micrographs confirmed that the Rhizobium leguminosarum-white clover interaction was not influenced by F- concentrations >100 mg L-1 . The toxic F- concentration for Rhizobium leguminosarum determined in this study is orders of magnitude higher than the F- concentration in New Zealand agriculture soils under "normal conditions." There appears to be no indication of imminent risk of soil F to Rhizobium leguminosarum.


Assuntos
Rhizobium leguminosarum , Trifolium , Flúor , Nova Zelândia , Simbiose
10.
Science ; 370(6514): 346-350, 2020 10 16.
Artigo em Inglês | MEDLINE | ID: mdl-33060360

RESUMO

Mutualisms, or reciprocally beneficial interspecific interactions, constitute the foundation of many ecological communities and agricultural systems. Mutualisms come in different forms, from pairwise interactions to extremely diverse communities, and they are continually challenged with exploitation by nonmutualistic community members (exploiters). Thus, understanding how mutualisms persist remains an essential question in ecology. Theory suggests that high species richness and functional redundancy could promote mutualism persistence in complex mutualistic communities. Using a yeast system (Saccharomyces cerevisiae), we experimentally show that communities with the greatest mutualist richness and functional redundancy are nearly two times more likely to survive exploitation than are simple communities. Persistence increased because diverse communities were better able to mitigate the negative effects of competition with exploiters. Thus, large mutualistic networks may be inherently buffered from exploitation.


Assuntos
Saccharomyces cerevisiae/fisiologia , Simbiose/fisiologia , Adenina/metabolismo , Biota , Lisina/genética , Lisina/metabolismo , Saccharomyces cerevisiae/genética , Simbiose/genética
12.
Zootaxa ; 4853(2): zootaxa.4853.2.9, 2020 Sep 22.
Artigo em Inglês | MEDLINE | ID: mdl-33056380

RESUMO

A new myrmecophilous species of root mealybug, Williamsrhizoecus udzungwensis sp. n., is described from individuals found living within a nest of Acropyga silvestrii in the Udzungwa Mountains of Tanzania. Acropyga ants are highly specialized, obligate associates of scale insects, typically members of the scale family Xenococcidae. Acropyga are best known for vertically transmitting trophobiotic partners during their nuptial flights and for housing them within brood chambers. This article presents the first record of trophobiosis between a species of Williamsrhizoecus and Acropyga, and only the second record of an association between Acropyga and rhizoecids in the Old World. This discovery contributes important information about the few species of Rhizoecidae confirmed to engage in these unique symbioses, each putatively the result of a past horizontal transmission event from a xenococcid to a rhizoecid lineage. Included is a discussion on the diagnosis of Williamsrhizoecus and an updated key to the species.


Assuntos
Formigas , Hemípteros , Animais , Simbiose , Tanzânia
13.
Mycorrhiza ; 30(6): 671-695, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-33043410

RESUMO

Despite decades of intensive research (especially from 1970s to 1990s), the ericoid mycorrhizal (ErM) hair root is still largely terra incognita and this simplified guide is intended to revive and promote the study of its mycobiota. Basic theoretical knowledge on the ErM symbiosis is summarized, followed by practical advices on Ericaceae root sample collection and handling, microscopic observations and photo-documentation of root fungal colonization, mycobiont isolation, maintenance and identification and resynthesis experiments with ericoid plants. The necessity of a proper selection of the root material and its surface sterilization prior to mycobiont isolation is stressed, together with the need of including suitable control treatments in inoculation experiments. The culture-dependent approach employing plating of single short (~ 2 mm) hair root segments on nutrient media is substantiated as a useful tool for characterization of Ericaceae root-associated fungal communities; it targets living mycelium and provides metabolically active cultures that can be used in physiological experiments and taxonomic studies, thus providing essential reference material for culture-independent approaches. On the other hand, it is stressed that not every mycobiont isolated from an ericoid hair root necessarily represent an ErM fungus. Likewise, not every intracellular hyphal coil formed in the Ericaceae rhizodermis necessarily represents the ErM symbiosis. Taxonomy of the most important ericoid mycobionts is updated, mutualism in the ErM symbiosis is briefly discussed from the mycobiont perspective, and some interesting lines of possible future research are highlighted.


Assuntos
Ericaceae , Micorrizas , Raízes de Plantas , Plantas , Simbiose
14.
Mycorrhiza ; 30(6): 715-723, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-33079241

RESUMO

Arbutus unedo (the strawberry tree) is a Mediterranean shrub which forms arbutoid mycorrhizae with a variety of Asco- and Basidiomycetes. After the discovery of the mycorrhizal symbiosis between A. unedo and Tuber borchii, in this study, arbutoid mycorrhizae were synthetized in greenhouse with Tuber aestivum and Tuber melanosporum. Six months after inoculation, both species colonized the roots of all inoculated A. unedo seedlings, but mature mycorrhizae were only observed after 12 months. Ultrastructure analysis of Tuber arbutoid mycorrhizae was described for the first time, showing, as observed in typical endosymbiosis, a rearrangement of host cells and the creation of an interface compartment with both truffle species. Immunolabelling experiments suggested that pectins are not present in the interface matrix surrounding the intracellular hyphae. Thus, the ability to establish symbiosis with A. unedo seems to be a common feature in the genus Tuber, opening up the possibility to use this plant for mycorrhization with valuable truffles. This could represent an important economic opportunity in Mediterranean areas by combining the production of truffles, edible fruits and valued honey.


Assuntos
Ascomicetos , Ericaceae , Micorrizas , Plântula , Simbiose
15.
PLoS One ; 15(10): e0239771, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33022020

RESUMO

Huanglongbing (HLB) is a deadly, incurable citrus disease putatively caused by the unculturable bacterium, 'Candidatus Liberibacter asiaticus' (CLas), and transmitted by Diaphorina citri. Prior studies suggest D. citri transmits CLas in a circulative and propagative manner; however, the precise interactions necessary for CLas transmission remain unknown, and the impact of insect sex on D. citri-CLas interactions is poorly understood despite reports of sex-dependent susceptibilities to CLas. We analyzed the transcriptome, proteome, metabolome, and microbiome of male and female adult D. citri reared on healthy or CLas-infected Citrus medica to determine shared and sex-specific responses of D. citri and its endosymbionts to CLas exposure. More sex-specific than shared D. citri responses to CLas were observed, despite there being no difference between males and females in CLas density or relative abundance. CLas exposure altered the abundance of proteins involved in immunity and cellular and oxidative stress in a sex-dependent manner. CLas exposure impacted cuticular proteins and enzymes involved in chitin degradation, as well as energy metabolism and abundance of the endosymbiont 'Candidatus Profftella armatura' in both sexes similarly. Notably, diaphorin, a toxic Profftella-derived metabolite, was more abundant in both sexes with CLas exposure. The responses reported here resulted from a combination of CLas colonization of D. citri as well as the effect of CLas infection on C. medica. Elucidating these impacts on D. citri and their endosymbionts contributes to our understanding of the HLB pathosystem and identifies the responses potentially critical to limiting or promoting CLas acquisition and propagation in both sexes.


Assuntos
Citrus/microbiologia , Hemípteros/microbiologia , Insetos Vetores/microbiologia , Doenças das Plantas/microbiologia , Rhizobiaceae/fisiologia , Rhizobiaceae/patogenicidade , Simbiose/fisiologia , Animais , Citrus/metabolismo , Citrus/fisiologia , Feminino , Hemípteros/metabolismo , Hemípteros/fisiologia , Insetos Vetores/metabolismo , Insetos Vetores/fisiologia , Masculino , Metaboloma/fisiologia , Microbiota/fisiologia , Estresse Oxidativo/fisiologia , Proteoma/metabolismo , Transcriptoma/fisiologia
16.
J Plant Res ; 133(6): 841-853, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-33099700

RESUMO

Mixotrophic plants obtain carbon by their own photosynthetic activity and from their root-associated mycorrhizal fungi. Mixotrophy is deemed a pre-adaptation for evolution of mycoheterotrophic nutrition, where plants fully depend on fungi and lose their photosynthetic activity. The aim of this study was to clarify mycorrhizal dependency and heterotrophy level in various phenotypes of mixotrophic Pyrola japonica (Ericaceae), encompassing green individuals, rare achlorophyllous variants (albinos) and a form with minute leaves, P. japonica f. subaphylla. These three phenotypes were collected in two Japanese forests. Phylogenetic analysis of both plants and mycorrhizal fungi was conducted based on DNA barcoding. Enrichment in 13C among organs (leaves, stems and roots) of the phenotypes with reference plants and fungal fruitbodies were compared by measuring stable carbon isotopic ratio. All plants were placed in the same clade, with f. subaphylla as a separate subclade. Leaf 13C abundances of albinos were congruent with a fully mycoheterotrophic nutrition, suggesting that green P. japonica leaves are 36.8% heterotrophic, while rhizomes are 74.0% heterotrophic. There were no significant differences in δ13C values among organs in both albino P. japonica and P. japonica f. subaphylla, suggesting full and high mycoheterotrophic nutrition, respectively. Among 55 molecular operational taxonomic units (OTUs) detected as symbionts, the genus Russula was the most abundant in each phenotype and its dominance was significantly higher in albino P. japonica and P. japonica f. subaphylla. Russula spp. detected in P. japonica f. subaphylla showed higher dissimilarity with other phenotypes. These results suggest that P. japonica sensu lato is prone to evolve mycoheterotrophic variants, in a process that changes its mycorrhizal preferences, especially towards the genus Russula for which this species has a marked preference.


Assuntos
Micorrizas , Pyrola/microbiologia , Código de Barras de DNA Taxonômico , Processos Heterotróficos , Japão , Filogenia , Folhas de Planta , Rizoma , Simbiose
17.
Ecol Lett ; 23(12): 1789-1799, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32969577

RESUMO

Ecological interactions shape the evolution of multiple species traits in populations. These traits are often linked to each other through genetic correlations, affecting how each trait evolves through selection imposed by interacting partners. Here, we integrate quantitative genetics, coevolutionary theory and network science to explore how trait correlations affect the coevolution of mutualistic species not only in pairs of species but also in species-rich networks across space. We show that genetic correlations may determine the pace of coevolutionary change, affect species abundances and fuel divergence among populations of the same species. However, this trait divergence promoted by genetic correlations is partially buffered by the nested structure of species-rich mutualisms. Our study, therefore, highlights how coevolution and its ecological consequences may result from conflicting processes at different levels of organisation, ranging from genes to communities.


Assuntos
Evolução Biológica , Simbiose , Fenótipo
18.
PLoS One ; 15(9): e0238943, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32925935

RESUMO

Inoculating plants with entomopathogenic fungi may influence plant nutrient uptake and growth, and herbivore performance. Knowledge is limited concerning the effects of this symbiosis on higher trophic levels. We examined how fungal treatment of faba bean seeds with the entomopathogenic fungus Beauveria bassiana influenced the choice-behavior and development of the aphid parasitoid Aphidius colemani. We also sampled plant material for analysis of changes in expression of genes related to plant defense pathways. While parasitoids were compatible with plants inoculated with B. bassiana initially (66 vs. 65% parasitization on inoculated and control plants, respectively; similar development times of parasitoids: 9.2 days), the emergence of adult parasitoids originating from aphids on fungus treated plants was significantly lower (67 vs. 76%, respectively). We also found that the defense response changed, similar to induced systemic resistance, when plants were treated with B. bassiana, similarly to what has been found for other plant symbiotic microorganisms. These novel findings show that although the application of entomopathogenic fungi to plants can alter the plants' defense against herbivores, it may also have an impact on beneficial insects, so their function and use should be evaluated on a case-by-case basis.


Assuntos
Beauveria/fisiologia , Controle Biológico de Vetores/métodos , Vicia faba/microbiologia , Beauveria/metabolismo , Beauveria/patogenicidade , Endófitos/fisiologia , Regulação da Expressão Gênica de Plantas/genética , Imunidade Vegetal/imunologia , Sementes/microbiologia , Simbiose , Vicia faba/metabolismo
19.
Mycorrhiza ; 30(6): 781-788, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32914374

RESUMO

Arbuscular mycorrhizal fungi are critical participants in plant nutrition in natural ecosystems and in sustainable agriculture. A large proportion of the phosphorus, nitrogen, sulfur, and transition metal elements that the host plant requires are obtained from the soil by the fungal mycelium and released at the arbuscules in exchange for photosynthates. While many of the plant transporters responsible for obtaining macronutrients at the periarbuscular space have been characterized, the identities of those mediating transition metal uptake remain unknown. In this work, MtCOPT2 has been identified as the only member of the copper transporter family COPT in the model legume Medicago truncatula to be specifically expressed in mycorrhizal roots. Fusing a C-terminal GFP tag to MtCOPT2 expressed under its own promoter showed a distribution pattern that corresponds with arbuscule distribution in the roots. When expressed in tobacco leaves, MtCOPT2-GFP co-localizes with a plasma membrane marker. MtCOPT2 is intimately related to the rhizobial nodule-specific MtCOPT1, which is suggestive of a shared evolutionary lineage that links transition metal nutrition in the two main root endosymbioses in legumes.


Assuntos
Medicago truncatula , Proteínas de Membrana Transportadoras , Micorrizas , Ecossistema , Regulação da Expressão Gênica de Plantas , Medicago truncatula/genética , Medicago truncatula/metabolismo , Proteínas de Membrana Transportadoras/metabolismo , Micorrizas/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Raízes de Plantas/metabolismo , Simbiose
20.
Mar Environ Res ; 162: 105125, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32919228

RESUMO

Coral reefs are being degraded worldwide by land reclamation and environmental factors, such as high seawater temperature, resulting in mass bleaching events. In addition, microplastics disturb the formation of coral-algae symbiotic relationships in primary polyps. In our experiments, we observed this effect in the bleached primary polyp Seriatopora caliendrum that lost its symbiont Symbiodiniaceae as a result of high water temperature. There was a higher incorporation of microspheres into bleached corals than in healthy ones. To understand the interference in symbiosis, we used the sea anemone Exaiptasia (as an anthozoan model organism) and fed it with microspheres. TEM results suggested the incorporation of microspheres and symbionts from the same phagocytosis zones in the mesenterial filament and endocytosis by the cells. In the tentacles, microspheres were in the same cell layer as the symbionts. These results suggest that microplastics occupy the spaces inhabited by Symbiodiniaceae, thereby hindering their symbiotic association.


Assuntos
Antozoários , Dinoflagelados , Animais , Recifes de Corais , Endoderma , Microplásticos , Plásticos/toxicidade , Simbiose
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA