Different pioneer plant species have similar rhizosphere microbial communities

Purpose The interactions between rhizosphere microorganisms and pioneer plants play important roles in the restoration of ecological functions after a disturbance. Different pioneer species appear in the initial phase of ecological restoration. However, the patterns of the composition of different pioneer species shaping the microbial communities of the rhizosphere are still poorly understood. Methods Microcosm experiments were established to compare the taxonomic and functional features of rhizosphere bacterial with fungal communities in response to plant species composition. Results Both bacterial and fungal communities didn't have significant variation related to the diversity, community composition, and predicted functions between rhizosphere soils collected from treatments containing different compositions of plant species. Rhizosphere bacteria were more sensitive to the external environment than fungi. The fungal diversity exhibited a more significant relationship with the traits of different plant species compared with bacteria. Similar plant traits, especially aboveground plant traits (i.e., total coverage, and aboveground biomass), were correlated with dominant taxa and functional profiles of the both bacterial and fungal community. Furthermore, network analyses showed that Gaiellales and Ganoderma were the key bacterial and fungal taxa, respectively, which played important roles in community assembly. Conclusions The composition of different pioneer species within a community had similar patterns of rhizosphere bacterial and fungal communities. The connection between plants and soil microorganisms was more likely related to plant traits instead of the species composition. Thus, the processes of plant growth and nutrient uptake, not the combinations of plant species, may be determinants of soil microbial community assemblage.