Biogeography of root‐associated fungi in foundation grasses of North American plains

Abstract

Aim: Roots and rhizospheres host diverse microbial communities that can influence the fitness, phenotypes, and environmental tolerances of plants. Documenting the biogeography of these microbiomes can detect the potential for a changing environment to disrupt host-microbe interactions, particularly in cases where microbes buffer hosts against abiotic stressors. We evaluated whether root-associated fungi had poleward declines in diversity, tested whether fungal communities in roots shifted near host plant range edges, and determined the relative importance of environmental and host predictors of root fungal community structure.Location: North American plains grasslands. Taxon: Foundation grasses -Andropogon gerardii, Bouteloua dactyloides, B. eriopoda, B. gracilis, and Schizachyrium scoparium and root fungi. Methods: At each of 24 sites representing three replicate 17°-latitudinal gradients, we collected roots from 12 individuals per species along five transects spaced 10 m apart (40 m × 40 m grid). We used next-generation sequencing of ITS2, direct fungal culturing from roots, and microscopy to survey fungi associated with grass roots. Results: Root-associated fungi did not follow the poleward declines in diversity documented for many animals and plants. Instead, host plant identity had the largest influence on fungal community structure. Edaphic factors outranked climate or host plant traits as correlates of fungal community structure; however, the relative importance of environmental predictors differed among plant species. As sampling approached host species range edges, fungal composition converged in similarity among individual plants of each grass species. Main conclusions: Environmental predictors of root-associated fungi depended strongly on host plant species identity. Biogeographic patterns in fungal composition suggested a homogenizing influence of stressors at host plant range limits. Resultspredict that communities of non-mycorrhizal, root-associated fungi in the North American plains will be more sensitive to future changes in host plant ranges and edaphic factors than to the direct effects of climate.

Bermudagrass Cultivars with Different Tolerance to Nematode Damage Are Characterized by Distinct Fungal but Similar Bacterial and Archaeal Microbiomes

“…The top BLAST hits indicate that these sequences might be related to Peniophora, a genus that was recently described from the leaves of wild grass [48]; therefore, the ASVs retrieved here might represent unknown Peniophora species. However, our results indicate that endophytic fungi were mostly represented by Ascomycota, in line with previous studies on fungal endophytes in grasses [44,[49][50][51]. A similar composition between Latitude 36 (T−) and TifTuf (T+), and across leaf and root endospheres and soil, was observed under lower taxonomic resolution, with leaf communities dominated by Dothideomycetes and root and soil communities by Sordariomycetes.…”

Precipitation, Not Land Use, Primarily Determines the Composition of Both Plant and Phyllosphere Fungal Communities

“…Plant communities and their shifts along gradients have been extensively studied (see Watson et al, 2021), whereas similar studies on fungal communities and/or their diversity are less common (but see e.g., Tedersoo et al, 2014;Glynou et al, 2016;Rudgers et al, 2021). Factors that may affect fungal communities include latitude (Arnold et al, 2000;Arnold and Lutzoni, 2007;Tedersoo et al, 2014), climate (McGuire et al, 2012U'ren et al, 2012;Zimmerman and Vitousek, 2012;Eusemann et al, 2016;Oita et al, 2021;Rudgers et al, 2021), soil (Tedersoo et al, 2020;Bowman and Arnold, 2021;Rudgers et al, 2021), plant host (Hoffman and Arnold, 2008;U'ren et al, 2012;Lau et al, 2013;Kembel and Mueller, 2014;Tedersoo et al, 2020;Rudgers et al, 2021), and disturbance (Delgado-Baquirizo et al, 2021). Some studies highlight strong host species and/or climatic/edaphic effects (e.g., Hoffman and Arnold, 2008;Tedersoo et al, 2020;Rudgers et al, 2021), whereas others find no support for correlations between plant community diversity and fungal communities (e.g., McGuire et al, 2012;Tedersoo et al, 2014).…”

“…Factors that may affect fungal communities include latitude (Arnold et al, 2000;Arnold and Lutzoni, 2007;Tedersoo et al, 2014), climate (McGuire et al, 2012U'ren et al, 2012;Zimmerman and Vitousek, 2012;Eusemann et al, 2016;Oita et al, 2021;Rudgers et al, 2021), soil (Tedersoo et al, 2020;Bowman and Arnold, 2021;Rudgers et al, 2021), plant host (Hoffman and Arnold, 2008;U'ren et al, 2012;Lau et al, 2013;Kembel and Mueller, 2014;Tedersoo et al, 2020;Rudgers et al, 2021), and disturbance (Delgado-Baquirizo et al, 2021). Some studies highlight strong host species and/or climatic/edaphic effects (e.g., Hoffman and Arnold, 2008;Tedersoo et al, 2020;Rudgers et al, 2021), whereas others find no support for correlations between plant community diversity and fungal communities (e.g., McGuire et al, 2012;Tedersoo et al, 2014). While soil-and root-inhabiting fungal communities may be buffered against climatic drivers (Rudgers et al, 2021) or correlate with plant diversity (Shen et al, 2021), phyllosphere communities may be particularly sensitive to climatic drivers whilst buffered against edaphic factors (Bowman and Arnold, 2021;Oita et al, 2021).…”

“…Some studies highlight strong host species and/or climatic/edaphic effects (e.g., Hoffman and Arnold, 2008;Tedersoo et al, 2020;Rudgers et al, 2021), whereas others find no support for correlations between plant community diversity and fungal communities (e.g., McGuire et al, 2012;Tedersoo et al, 2014). While soil-and root-inhabiting fungal communities may be buffered against climatic drivers (Rudgers et al, 2021) or correlate with plant diversity (Shen et al, 2021), phyllosphere communities may be particularly sensitive to climatic drivers whilst buffered against edaphic factors (Bowman and Arnold, 2021;Oita et al, 2021). Consistent with our hypotheses and predictions, our data strongly suggest that phyllosphere fungal communities respond to MAP.…”

Bacterial but Not Fungal Rhizosphere Community Composition Differ among Perennial Grass Ecotypes under Abiotic Environmental Stress

“…Microorganisms in the rhizosphere are sensitive to environmental conditions ( 16 ) and can be good indicators of soil quality ( 17 ). Dissecting the rhizosphere bacterial and fungal communities, their functional roles, and their interactions with the plant hosts are crucial to developing future methods to improve drought tolerance and plant productivity.…”