Biology subjects

Tanabe, A. S.

Publications and source records attributed to Tanabe, A. S..

3 recordsLinked to original sources

bioRxiv2018

Network hubs in root-associated fungal metacommunities

BackgroundAlthough a number of recent studies have uncovered remarkable diversity of microbes associated with plants, understanding and managing dynamics of plant microbiomes remain major scientific challenges. In this respect, network analytical methods have provided a basis for exploring \"hub\" microbial species, which potentially organize community-scale processes of plant-microbe interactions.\n\nMethodsBy compiling Illumina sequencing data of root-associated fungi in eight forest ecosystems across the Japanese Archipelago, we explored hubs within \"metacommunity-scale\" networks of plant-fungus associations. In total, the metadata included 8,080 fungal operational taxonomic units (OTUs) detected from 227 local populations of 150 plant species/taxa.\n\nResultsFew fungal OTUs were common across all the eight forests. However, in each metacommunity-scale network representing northern four localities or southern four localities, diverse mycorrhizal, endophytic, and pathogenic fungi were classified as \"metacommunity hubs\", which were detected from diverse host plant taxa throughout a climatic region. Specifically, Mortierella (Mortierellales), Cladophialophora (Chaetothyriales), Ilyonectria (Hypocreales), Pezicula (Helotiales), and Cadophora (incertae sedis) had broad geographic and host ranges across the northern (cool-temperate) region, while Saitozyma/Cryptococcus (Tremellales/Trichosporonales) and Mortierella as well as some arbuscular mycorrhizal fungi were placed at the central positions of the metacommunity-scale network representing warm-temperate and subtropical forests in southern Japan.\n\nConclusionsThe network theoretical framework presented in this study will help us explore prospective fungi and bacteria, which have high potentials for agricultural application to diverse plant species within each climatic region. As some of those fungal taxa with broad geographic and host ranges have been known to increase the growth and pathogen resistance of host plants, further studies elucidating their functional roles are awaited.

microbiology↗

bioRxiv2018

Structural diversity across arbuscular mycorrhizal, ectomycorrhizal, and endophytic plant-fungus networks

BackgroundBelow-ground linkage between plant and fungal communities is one of the major drivers of terrestrial ecosystem dynamics. However, we still have limited knowledge of how such plant-fungus associations vary in their community-scale properties depending on fungal functional groups and geographic locations.\n\nMethodsBased on high-throughput sequencing of root-associated fungi in eight forests along the Japanese Archipelago, we performed a comparative analysis of arbuscular mycorrhizal, ectomycorrhizal, and saprotrophic/endophytic associations across a latitudinal gradient from cool-temperate to subtropical regions.\n\nResultsIn most of the plant-fungus networks analyzed, host-symbiont associations were significantly specialized but lacked \"nested\" architecture, which has been commonly reported in plant-pollinator and plant-seed disperser networks. Meanwhile, the structure of arbuscular mycorrhizal networks was differentiated from that of ectomycorrhizal and saprotrophic/endophytic networks, characterized by high connectance. Our data also suggested that geographic factors affected the organization of plant-fungus network structure. For example, the southernmost subtropical site analyzed in this study displayed lower network-level specificity of host-symbiont associations and higher (but still low) nestedness than northern localities.\n\nConclusionsOur comparative analyses suggest that arbuscular mycorrhizal, ectomycorrhizal, and saprotrophic/endophytic plant-fungus associations often lack nested network architecture, while those associations can vary, to some extent, in their community-scale properties along a latitudinal gradient. Overall, this study provides a basis for future studies that will examine how different types of plant-fungus associations collectively structure terrestrial ecosystems.

microbiology↗

bioRxiv2017

Plant-soil feedbacks between arbuscular- and ecto-mycorrhizal communities

Soil microbiomes of adult trees exert species-specific effects on the survival and growth of seedlings1-6, yet empirical evidence that such plant-soil microbiome interaction drives seedling community assembly remains scarce. Here we show that mycorrhizal fungal communities determine seedling community assembly by controlling how resident plant communities alter the growth of newly established seedlings. We reciprocally introduced seedling communities of arbuscular-and ecto-mycorrhizal plant species to replicated mesocosms to follow the effects of mycorrhizal type match/mismatch with resident plant communities on seedling growth rates. The growth rates of recruited seedlings were generally higher under resident trees of the same mycorrhizal types than under those of different mycorrhizal types, generating positive plant-soil feedbacks through mycorrhizal-type matching. Such positive effects of matching were linked with seedlings greater acquisition rates of mycorrhizal symbionts from matched resident plants than from mismatched plants, and such linkage was pronounced for ecto-mycorrhizal plant species. In contrast, under the condition of mycorrhizal-type matching between resident plants and seedlings (i.e., within-mycorrhizal-type comparison), plant-soil feedback effects varied considerably in their sign and strength among resident-seedling species combinations. Consequently, the assembly of a temperate tree seedling community is driven by a combination of species-specific plant-soil feedbacks and the match/mismatch of mycorrhizal type between resident plants and seedlings.

ecology↗