AUTHOR=Zuo Yi-Ling , Hu Qian-Nan , Qin Le , Liu Jia-Qiang , He Xue-Li 

TITLE=Species identity and combinations differ in their overall benefits to Astragalus adsurgens plants inoculated with single or multiple endophytic fungi under drought conditions

JOURNAL=Frontiers in Plant Science

VOLUME=13

YEAR=2022

URL=https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2022.933738

DOI=10.3389/fpls.2022.933738

ISSN=1664-462X

ABSTRACT=<p>Although desert plants often establish multiple simultaneous symbiotic associations with various endophytic fungi in their roots, most studies focus on single fungus inoculation. Therefore, combined inoculation of multiple fungi should be applied to simulate natural habitats with the presence of a local microbiome. Here, a pot experiment was conducted to test the synergistic effects between three extremely arid habitat-adapted root endophytes (<italic>Alternaria chlamydospora, Sarocladium kiliense</italic>, and <italic>Monosporascus</italic> sp.). For that, we compared the effects of single fungus <italic>vs</italic>. combined fungi inoculation, on plant morphology and rhizospheric soil microhabitat of desert plant <italic>Astragalus adsurgens</italic> grown under drought and non-sterile soil conditions. The results indicated that fungal inoculation mainly influenced root biomass of <italic>A. adsurgens</italic>, but did not affect the shoot biomass. Both single fungus and combined inoculation decreased plant height (7–17%), but increased stem branching numbers (13–34%). However, fungal inoculation influenced the root length and surface area depending on their species and combinations, with the greatest benefits occurring on <italic>S. kiliense</italic> inoculation alone and its co-inoculation with <italic>Monosporascus</italic> sp. (109% and 61%; 54% and 42%). Although <italic>A. chlamydospora</italic> and co-inoculations with <italic>S. kiliense</italic> and <italic>Monosporascus</italic> sp. also appeared to promote root growth, these inoculations resulted in obvious soil acidification. Despite no observed root growth promotion, <italic>Monosporascus</italic> sp. associated with its combined inoculations maximally facilitated soil organic carbon accumulation. However, noticeably, combined inoculation of the three species had no significant effects on root length, surface area, and biomass, but promoted rhizospheric fungal diversity and abundance most, with <italic>Sordariomycetes</italic> being the dominant fungal group. This indicates the response of plant growth to fungal inoculation may be different from that of the rhizospheric fungal community. Structural equation modeling also demonstrated that fungal inoculation significantly influenced the interactions among the growth of <italic>A. adsurgens</italic>, soil factors, and rhizospheric fungal groups. Our findings suggest that, based on species-specific and combinatorial effects, endophytic fungi enhanced the plant root growth, altered soil nutrients, and facilitated rhizospheric fungal community, possibly contributing to desert plant performance and ecological adaptability. These results will provide the basis for evaluating the potential application of fungal inoculants for developing sustainable management for desert ecosystems.</p>