By assessing diversity variations of bacterial communities under different rhizocompartment types (i.e., roots, rhizosphere soil, root zone soil, and inter-shrub bulk soil), we explore the structural variability of bacterial communities in different root microenvironments under desert leguminous plant shrubs. Results will enable the influence of niche differentiation of plant roots and root soil on the structural stability of bacterial communities under three desert leguminous plant shrubs to be examined. High-throughput 16S rRNA genome sequencing was used to characterize diversity and structural differences of bacterial microbes in the rhizocompartments of three xeric leguminous plants. Results from this study confirm previous findings relating to niche differentiation in rhizocompartments under related shrubs, and they demonstrate that diversity and structural composition of bacterial communities have significant hierarchical differences across four rhizocompartment types under leguminous plant shrubs. Desert leguminous plants had significant effects on the enrichment and filtration of specific bacterial microbiomes across different rhizocompartments (P<0.05). The core bacterial microbiomes causing structure and composition variability of bacterial communities across different niches of desert leguminous plants are also identified. By investigating the influence of niches on the structural variability of soil bacterial communities with the differentiation of rhizocompartments under desert leguminous plant shrubs, we provide data support for the identification of dominant bacteria and future preparation of inocula, and provide a foundation for further study of the host plants-microbial interactions.
IMPORTANCEColonization by plant communities make valued contribution to sand-fixing in poor ecological desert environments, thereby reducing the effects of wind erosion in these areas. Our study revealed that specific core bacterial microbiomes in under-shrub soil microbial communities had a significant hierarchical enrichment effect among rhizocompartments, and were filtered into roots. The root endophyte microbiomes thus formed had low abundance and diversity, but their structural variability was the highest. In addition, our data also verified that the rhizocompartments of under desert leguminous plant shrubs had a significant differentiation effect for the core bacterial microbiomes enriched and filtered by host plants, and that each rhizocompartment represented a unique niche of bacterial communities. Understanding the interactions between xeric shrubs and soil microbial communities is a fundamental step for describing desert soil ecosystems, which in turn can offer a microbe-associated reference for evaluating the restoration of desert vegetation.
