Defining microbiome communities in banana (Musa spp.) with and without symptoms of Fusarium wilt

We assessed the diversity, structure, and assemblage of bacterial and fungal communities associated with banana plants with and without Fusarium oxysporum f. sp. cubense (Foc) symptoms. A total of 117,814 bacterial and 17,317 fungal operational taxonomy units (OTUs) were identified in the rhizosphere, roots, and corm of the host plant. Results revealed that bacterial and fungal microbiota present in roots and corm primarily emanated from the rhizosphere. The composition of bacterial communities in the rhizosphere, roots, and corm were different, with more diversity observed in the rhizosphere and less in the corm. However, distinct sample types i.e., without (asymptomatic) and with (symptomatic) Fusarium symptoms were the major drivers of the fungal community composition. Considering the high relative abundance among samples, we identified core microbiomes with bacterial and fungal OTUs classified into 20 families and colonizing distinct plant components of banana. Our core microbiome assigned 129 bacterial and 37 fungal genera to known taxa.

Download Full-text

Activation of the SA-Associated Plant Defense Pathway Alters the Composition of Soil Bacterial Communities

10.21203/rs.3.rs-159617/v1 ◽

2021 ◽

Author(s):

Jing Zhang ◽

Peter G.L. Klinkhamer ◽

Klaas Vrieling ◽

T. Martijn Bezemer

Keyword(s):

Plant Growth ◽

Microbial Communities ◽

Signaling Pathway ◽

Bacterial Communities ◽

Rhizosphere Soil ◽

Soil Microbial Communities ◽

Core Microbiome ◽

Soil Microbial ◽

Soil Bacterial ◽

Sa Signaling

Abstract Background and aimsMany plant species grow better in sterilized than in live soil. Foliar application of SA mitigates this negative effect of live soil on the growth of the plant Jacobaea vulgaris. To examine what causes the positive effect of SA application on plant growth in live soils, we analyzed the effects of SA application on the composition of active rhizosphere bacteria in the live soil. Methods We studied this over four consecutive plant cycles (generations), using mRNA sequencing of the microbial communities in the rhizosphere of J. vulgaris. ResultsOur study shows that the composition of the rhizosphere bacterial communities of J. vulgaris greatly differed among generations. Application of SA resulted in both increases and decreases in a number of active bacterial genera in the rhizosphere soil, but the genera that were affected by the treatment differed among generations. In the first generation, there were no genera that were significantly affected by the SA treatment, indicating that induction of the SA defense pathway in plants does not lead to immediate changes in the soil microbial community. 89 species out of the total 270 (32.4%) were present in all generations in all soils of SA-treated and control plants suggesting that these make up the “core” microbiome. On average in each generation, 72.9% of all genera were present in both soils. Application of SA to plants significantly up-regulated genera of Caballeronia, unclassified Cytophagaceae, Crinalium and Candidatus Thermofonsia Clade 2, and down-regulated genera of Thermomicrobiales, unclassified Rhodobacterales, Paracoccus and Flavihumibacter. While the functions of many of these bacteria are poorly understood, bacteria of the genus Caballeronia play an important role in fixing nitrogen and promoting plant growth, and hence this suggests that activation of the SA signaling pathway in J. vulgaris plants may select for bacterial genera that are beneficial to the plant. ConclusionsOverall, our study shows that aboveground activation of defenses in the plant affects soil microbial communities and, as soil microbes can greatly influence plant performance, this implies that induction of plant defenses can lead to complex above-belowground feedbacks. Further studies should examine how activation of the SA signaling pathway in the plant changes the functional genes of the rhizosphere soil bacterial community.

Download Full-text

Ecological networks reveal contrasting patterns of bacterial and fungal communities in glacier-fed streams in Central Asia

10.7287/peerj.preprints.27887 ◽

2019 ◽

Cited By ~ 1

Author(s):

Ze Ren ◽

Hongkai Gao

Keyword(s):

Bacterial Community ◽

Microbial Communities ◽

Central Asia ◽

Fungal Community ◽

Bacterial Communities ◽

Beta Diversity ◽

Hydrological Modeling ◽

Alpha Diversity ◽

Environmental Variation ◽

Fungal Communities

Bacterial and fungal communities in biofilms are important components in driving biogeochemical processes in stream ecosystems. Previous studies have well documented the patterns of bacterial alpha diversity in stream biofilms in glacier-fed streams, where, however, beta diversity of the microbial communities has received much less attention especially considering both bacterial and fungal communities. A focus on beta diversity can provide insights into the mechanisms driving community changes associated to large environmental fluctuations and disturbances, such as in glacier-fed streams. Moreover, modularity of co-occurrence networks can reveal more ecological and evolutionary properties of microbial communities beyond taxonomic groups. Here, integrating beta diversity and co-occurrence approach, we explored the network topology and modularity of the bacterial and fungal communities with consideration of environmental variation in glacier-fed streams in Central Asia. Combining results from hydrological modeling and normalized difference of vegetation index, this study highlighted that hydrological variables and vegetation status are major variables determining the environmental heterogeneity of glacier-fed streams. Bacterial communities formed a more complex and connected network, while the fungal communities formed a more clustered network. Moreover, the strong interrelations among the taxonomic dissimilarities of bacterial community and modules suggest they had common processes in driving diversity and taxonomic compositions across the heterogeneous environment. In contrast, fungal community and modules generally showed distinct driving processes to each other. Moreover, bacterial and fungal communities also had different driving processes. Furthermore, the variation of bacterial community and modules were strongly correlated with hydrological properties and vegetation status but not with nutrients, while fungal community and modules (except one module) were not associated with environmental variation. Our results suggest that bacterial and fungal communities had distinct mechanisms in structuring microbial networks, and environmental variation had strong influences on bacterial communities but not on fungal communities. The fungal communities have unique assembly mechanisms and physiological properties which might lead to their insensitive responses to environmental variations compared to bacterial communities. Overall, beyond alpha diversity in previous studies, these results add our knowledge that bacterial and fungal communities have contrasting assembly mechanisms and respond differently to environmental variation in glacier-fed streams.

Download Full-text

Ecological networks reveal contrasting patterns of bacterial and fungal communities in glacier-fed streams in Central Asia

10.7287/peerj.preprints.27887v1 ◽

2019 ◽

Author(s):

Ze Ren ◽

Hongkai Gao

Keyword(s):

Bacterial Community ◽

Microbial Communities ◽

Central Asia ◽

Fungal Community ◽

Bacterial Communities ◽

Beta Diversity ◽

Hydrological Modeling ◽

Alpha Diversity ◽

Environmental Variation ◽

Fungal Communities

Bacterial and fungal communities in biofilms are important components in driving biogeochemical processes in stream ecosystems. Previous studies have well documented the patterns of bacterial alpha diversity in stream biofilms in glacier-fed streams, where, however, beta diversity of the microbial communities has received much less attention especially considering both bacterial and fungal communities. A focus on beta diversity can provide insights into the mechanisms driving community changes associated to large environmental fluctuations and disturbances, such as in glacier-fed streams. Moreover, modularity of co-occurrence networks can reveal more ecological and evolutionary properties of microbial communities beyond taxonomic groups. Here, integrating beta diversity and co-occurrence approach, we explored the network topology and modularity of the bacterial and fungal communities with consideration of environmental variation in glacier-fed streams in Central Asia. Combining results from hydrological modeling and normalized difference of vegetation index, this study highlighted that hydrological variables and vegetation status are major variables determining the environmental heterogeneity of glacier-fed streams. Bacterial communities formed a more complex and connected network, while the fungal communities formed a more clustered network. Moreover, the strong interrelations among the taxonomic dissimilarities of bacterial community and modules suggest they had common processes in driving diversity and taxonomic compositions across the heterogeneous environment. In contrast, fungal community and modules generally showed distinct driving processes to each other. Moreover, bacterial and fungal communities also had different driving processes. Furthermore, the variation of bacterial community and modules were strongly correlated with hydrological properties and vegetation status but not with nutrients, while fungal community and modules (except one module) were not associated with environmental variation. Our results suggest that bacterial and fungal communities had distinct mechanisms in structuring microbial networks, and environmental variation had strong influences on bacterial communities but not on fungal communities. The fungal communities have unique assembly mechanisms and physiological properties which might lead to their insensitive responses to environmental variations compared to bacterial communities. Overall, beyond alpha diversity in previous studies, these results add our knowledge that bacterial and fungal communities have contrasting assembly mechanisms and respond differently to environmental variation in glacier-fed streams.

Download Full-text

Mixed-Cropping Between Field Pea Varieties Alters Root Bacterial and Fungal Communities

Scientific Reports ◽

10.1038/s41598-019-53342-8 ◽

2019 ◽

Vol 9 (1) ◽

Cited By ~ 3

Author(s):

Anthony Horner ◽

Samuel S. Browett ◽

Rachael E. Antwis

Keyword(s):

Microbial Communities ◽

Bacterial Communities ◽

Crop Production ◽

Agricultural Soils ◽

Critical Role ◽

Agricultural Practices ◽

Microbial Interactions ◽

Field Pea ◽

Fungal Communities ◽

Mixed Cropping

AbstractModern agricultural practices have vastly increased crop production but negatively affected soil health. As such, there is a call to develop sustainable, ecologically-viable approaches to food production. Mixed-cropping of plant varieties can increase yields, although impacts on plant-associated microbial communities are unclear, despite their critical role in plant health and broader ecosystem function. We investigated how mixed-cropping between two field pea (Pisum sativum L.) varieties (Winfreda and Ambassador) influenced root-associated microbial communities and yield. The two varieties supported significantly different fungal and bacterial communities when grown as mono-crops. Mixed-cropping caused changes in microbial communities but with differences between varieties. Root bacterial communities of Winfreda remained stable in response to mixed-cropping, whereas those of Ambassador became more similar to Winfreda. Conversely, root fungal communities of Ambassador remained stable under mixed-cropping, and those of Winfreda shifted towards the composition of Ambassador. Microbial co-occurrence networks of both varieties were stronger and larger under mixed-cropping, which may improve stability and resilience in agricultural soils. Both varieties produced slightly higher yields under mixed-cropping, although overall Ambassador plants produced higher yields than Winfreda plants. Our results suggest that variety diversification may increase yield and promote microbial interactions.

Download Full-text

Crop, genotype, and field environmental conditions shape bacterial and fungal seed epiphytic microbiomes

Canadian Journal of Microbiology ◽

10.1139/cjm-2020-0306 ◽

2020 ◽

pp. 1-13

Author(s):

Zayda P. Morales Moreira ◽

Bobbi L. Helgason ◽

James J. Germida

Keyword(s):

Environmental Conditions ◽

Amplicon Sequencing ◽

Fungal Communities ◽

Plant Fitness ◽

Microbial Composition ◽

Core Microbiome ◽

Reproductive Structures ◽

Microbial Assemblage ◽

Crop Type ◽

Diversity Structure

Seeds are reproductive structures able to carry and transfer microorganisms that play an important role in plant fitness. Genetic and external factors are reported to be partly responsible for the plant microbiome assemblage, but their contribution in seeds is poorly understood. In this study, wheat, canola, and lentil seeds were analyzed to characterize diversity, structure, and persistence of seed-associated microbial communities. Five lines and 2 generations of each crop were subjected to high-throughput amplicon sequencing of the 16S rRNA and internal transcribed spacer (ITS) regions. Bacterial and fungal communities differed most by crop type (30% and 47% of the variance), while generation explained an additional 10% and 15% of the variance. The offspring (i.e., generation harvested in 2016 at the same location) exhibited a higher number of common amplicon sequence variants (ASVs) and less variability in microbial composition. Additionally, in every sample analyzed, a “core microbiome” was detected consisting of 5 bacterial and 12 fungal ASVs. Our results suggest that crop, genotype, and field environmental conditions contributed to the seed-associated microbial assemblage. These findings not only expand our understanding of the factors influencing the seed microbiome but may also help us to manipulate and exploit the microbiota naturally carried by seeds.

Download Full-text

Fast response of fungal and prokaryotic communities to climate change manipulation in two contrasting tundra soils

Environmental Microbiome ◽

10.1186/s40793-019-0344-4 ◽

2019 ◽

Vol 14 (1) ◽

Author(s):

Jana Voříšková ◽

Bo Elberling ◽

Anders Priemé

Keyword(s):

Organic Matter ◽

Seasonal Variation ◽

Snow Cover ◽

Bacterial Communities ◽

Winter Precipitation ◽

Fungal Communities ◽

Tundra Soils ◽

Short Term ◽

Fungal Community Composition ◽

Climate Manipulation

Abstract Background Climate models predict substantial changes in temperature and precipitation patterns across Arctic regions, including increased winter precipitation as snow in the near future. Soil microorganisms are considered key players in organic matter decomposition and regulation of biogeochemical cycles. However, current knowledge regarding their response to future climate changes is limited. Here, we explore the short-term effect of increased snow cover on soil fungal, bacterial and archaeal communities in two tundra sites with contrasting water regimes in Greenland. In order to assess seasonal variation of microbial communities, we collected soil samples four times during the plant-growing season. Results The analysis revealed that soil microbial communities from two tundra sites differed from each other due to contrasting soil chemical properties. Fungal communities showed higher richness at the dry site whereas richness of prokaryotes was higher at the wet tundra site. We demonstrated that fungal and bacterial communities at both sites were significantly affected by short-term increased snow cover manipulation. Our results showed that fungal community composition was more affected by deeper snow cover compared to prokaryotes. The fungal communities showed changes in both taxonomic and ecological groups in response to climate manipulation. However, the changes were not pronounced at all sampling times which points to the need of multiple sampling in ecosystems where environmental factors show seasonal variation. Further, we showed that effects of increased snow cover were manifested after snow had melted. Conclusions We demonstrated rapid response of soil fungal and bacterial communities to short-term climate manipulation simulating increased winter precipitation at two tundra sites. In particular, we provide evidence that fungal community composition was more affected by increased snow cover compared to prokaryotes indicating fast adaptability to changing environmental conditions. Since fungi are considered the main decomposers of complex organic matter in terrestrial ecosystems, the stronger response of fungal communities may have implications for organic matter turnover in tundra soils under future climate.

Download Full-text

The gut mycobiome of healthy mice is shaped by the environment and shapes metabolic outcomes in response to diet

10.1101/2020.06.25.158287 ◽

2020 ◽

Author(s):

Tahliyah S. Mims ◽

Qusai Al Abdullah ◽

Justin D. Stewart ◽

Sydney P. Watts ◽

Catrina T. White ◽

...

Keyword(s):

Community Composition ◽

Fungal Community ◽

Bacterial Communities ◽

Genetic Background ◽

Dietary Exposure ◽

Fungal Communities ◽

Metabolic Adaptation ◽

Fungal Community Composition ◽

Metabolic Outcomes ◽

Metabolic Biomarkers

ABSTRACTObjectiveAs an active interface between the host and their diet, the gut bacteriome influences host metabolic adaptation. However, the contribution of gut fungi to host metabolic outcomes is not yet understood. Therefore, we aimed to determine if host metabolic response to an ultra-processed diet reflects gut fungal community composition.DesignWe compared jejunal fungi and bacteria from 72 healthy mice with the same genetic background but different starting mycobiomes before and after 8 weeks on an ultra-processed or standardized diet using 16S and internal transcribed spacer region 2 ribosomal RNA sequencing. We measured host body composition using magnetic resonance imaging, examined changes in metabolically active host tissues and quantified serum metabolic biomarkers.ResultsGut fungal communities are highly variable between mice, differing by vendor, age and sex. After exposure to an ultra-processed diet for 8 weeks, persistent differences in fungal community composition strongly associate with differential deposition of body mass in male mice compared to mice on standardized diet. Fat deposition in the liver, genomic adaptation of metabolically active tissues and serum metabolic biomarkers are correlated with alterations in fungal diversity and community composition. Variation in fungi from the genera Thermomyces and Saccharomyces most strongly associate with increased weight gain.ConclusionsIn the gut of healthy mice, host-microbe metabolic interactions strongly reflect variability in fungal communities. Our results confirm the importance of luminal fungal communities to host metabolic adaptation to dietary exposure. Gut fungal communities may represent a therapeutic target for the prevention and treatment of metabolic disease.Graphical AbstractIn BriefWhat is already known about this subject?Gut bacterial communities have evolved to influence the metabolic outcomes of the host in mammals. Evidence from across the lifespan suggests that differences in composition of these communities is associated with energy consumption. However, gut microbial communities, while often equated to bacteria, are diverse, multi-kingdom ecologies and limited information is available for the role of other kingdoms of life, such as fungi.What are the new findings?Gut fungal communities, collectively termed the mycobiome, are less diverse and abundant than bacterial communities in the gastrointestinal tract. This study identifies the considerable influence of the environment and dietary exposure on the composition of jejunal fungal communities in healthy mice with the same genetic background. After exposure to processed diet, differences in fungal community composition in male mice were strongly correlated with persistent differences body composition and markers of metabolic tone.How might it impact on clinical practice in the foreseeable future?These results verify that the baseline metabolic tone of health mice strongly reflects the ecological complexity of the gastrointestinal mycobiome. Variation in the composition of gut fungal communities is likely an underappreciated source of experimental and clinical variability in metabolic studies. Gastrointestinal fungi are likely a target for prevention and treatment of metabolic disease.

Download Full-text

Rhizosphere Community Selection Reveals Bacteria Associated With Reduced Root Disease

10.21203/rs.3.rs-64051/v1 ◽

2020 ◽

Author(s):

Chuntao Yin ◽

Juan M. Casa Vargas ◽

Daniel C. Schlatter ◽

Christina H. Hagerty ◽

Scot H. Hulbert ◽

...

Keyword(s):

Bacterial Community ◽

Plant Growth ◽

Microbial Communities ◽

Bacterial Communities ◽

Wheat Root ◽

Root Disease ◽

Plant Diseases ◽

16S Rrna Genes ◽

Rrna Genes

Abstract Background: Microbes benefit plants by increasing nutrient availability, producing plant growth hormones, and protecting against pathogens. However, it is largely unknown how plants change root microbial communities. Results: In this study, we used a multi-cycle selection system and infection by the soilborne fungal pathogen Rhizoctonia solani AG8 (hereafter AG8) to examine how plants impact the rhizosphere bacterial community and recruit beneficial microorganisms to suppress soilborne fungal pathogens and promote plant growth. Successive plantings dramatically enhanced disease suppression on susceptible wheat cultivars to AG8 in the greenhouse. Accordingly, analysis of the rhizosphere soil microbial community using deep sequencing of 16S rRNA genes revealed distinct bacterial community profiles assembled over successive wheat plantings. Moreover, the cluster of bacterial communities formed from the AG8-infected rhizosphere was distinct from those without AG8 infection. Interestingly, the bacterial communities from the rhizosphere with the lowest wheat root disease gradually separated from those with the worst wheat root disease over planting cycles. Successive monocultures and application of AG8 increased the abundance of some bacterial genera which have potential antagonistic activities, such as Chitinophaga, Pseudomonas, Chryseobacterium, and Flavobacterium, and a group of plant growth-promoting (PGP) and nitrogen-fixing microbes, including Pedobacter, Variovorax, and Rhizobium. Furthermore, 47 bacteria isolates belong to 35 species were isolated. Among them, eleven and five exhibited antagonistic activities to AG8 and Rhizoctonia oryzae in vitro, respectively. Notably, Janthinobacterium displayed broad antagonism against the soilborne pathogens Pythium ultimum, AG8, and R. oryzae in vitro, and disease suppressive activity to AG8 in soil. Conclusions: Our results demonstrated that successive wheat plantings and pathogen infection can shape the rhizosphere microbial communities and specifically accumulate a group of beneficial microbes. Our findings suggest that soil community selection may offer the potential for addressing agronomic concerns associated with plant diseases and crop productivity.

Download Full-text

Seasonal Dynamics of Core Fungi in the Switchgrass Phyllosphere, and Co-Occurrence with Leaf Bacteria

Phytobiomes Journal ◽

10.1094/pbiomes-07-20-0051-r ◽

2020 ◽

pp. PBIOMES-07-20-0

Author(s):

Alan W. Bowsher ◽

Gian Maria Niccolò Benucci ◽

Gregory Bonito ◽

Ashley Shade

Keyword(s):

Seasonal Dynamics ◽

Nitrogen Concentration ◽

Temporal Patterns ◽

Matter Content ◽

Fungal Communities ◽

Published Data ◽

Strong Impact ◽

Dry Matter Content ◽

Fungal Community Composition ◽

Microbiome Assembly

Plant leaves harbor complex microbial communities that influence plant health and productivity. Nevertheless, a detailed understanding of phyllosphere community assembly and drivers is needed, particularly for phyllosphere fungi. Here, we investigated seasonal dynamics of epiphytic phyllosphere fungal communities in switchgrass (Panicum virgatum L.), a focal bioenergy crop. We also leverage previously published data on switchgrass phyllosphere bacterial communities from the same experimental plants, allowing us to compare fungal and bacterial dynamics and explore interdomain network associations in the switchgrass phyllosphere. Overall, we found a strong impact of sampling date on fungal community composition, with multiple taxonomic levels exhibiting clear temporal patterns in relative abundance. In addition, leaf nitrogen concentration, leaf dry matter content, plant height, and minimum daily air temperature explained significant variation in phyllosphere fungal communities, likely due to their correlation with sampling date. Finally, among the core taxa, fungi–bacteria network associations were much more common than bacteria–bacteria associations, suggesting the importance of interdomain phylogenetic diversity in microbiome assembly. Although our findings highlight the complexity of phyllosphere microbiome assembly, the clear temporal patterns in lineage-specific fungal abundances give promise to the potential for accurately predicting shifts in fungal phyllosphere communities throughout the growing season, a key research priority for sustainable agriculture. [Formula: see text] Copyright © 2020 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license .

Download Full-text