Impact of the soil springtail Folsomia candida on the composition, function, and microbial network of root-associated microbes of host plant Sedum plumbizincicola

Plant root-associated microorganisms play a major role in promoting plant growth and suppressing pathogenic bacteria. Soil animals in complex soil systems, and especially springtails, interact closely with plants and microorganisms by preying on microorganisms and feeding on roots. However, currently there is a lack of knowledge about how soil springtails modify microbes associated with plant roots. Here the bacterial and fungal communities in the rhizosphere and endosphere of Sedum plumbizincicola in the presence of a soil springtail were investigated. 16S rRNA and ITS gene sequencing were used together with assessments of microbial biomass and carbon source utilization in the rhizosphere. The presence of the springtail did not impact the overall diversity of the microbial community or its assembly processes but it did alter the abundance of specific microorganisms. The springtail influenced the relative abundance of the genus Pseudomonas and the class Nitrospira in the rhizosphere. Moreover, the springtail increased the biomass and carbon source utilization of rhizosphere microbes and influenced the abundance of nitrogen cycle genes. Co-occurrence network analysis revealed an increase in the average degree and total number of nodes and edges within the microbial network in the presence of the springtail, indicating heightened microbial interactions and a more stable network. The results indicate that the springtail regulated the ecological functions of plant root-associated microorganisms and highlight for the first time the role of soil springtails in regulating the microbial community and functions associated with plant roots.