Analysis of Microbial Community Structure Around Roots of Stipa Grandis

Abstract The root zone microbial structure is particularly complex for plants with rhizosheaths, which may play an important role in the future agricultural sustainable development. However, one of the important reasons for restricting our study of rhizosheath microbial structure is that there is no definite method for rhizosheath separation. The aim of this study was to explore the isolation methods of rhizosheath and the diversity and functional characteristics of microorganisms around the rhizosphere. In this study, we isolated the rhizosheath of Stipa grandis, a dominant species in desert steppe, and the microorganisms in the roots, root epidermis, rhizosheath, rhizosphere soil were extracted and sequenced by 16s RNA and ITS. The bacterial alpha diversity index was in the order rhizosphere soil > rhizosheath > root epidermis > endophytic, and the fungal alpha diversity index was rhizosphere soil and rhizosheath > root epidermis and endophytic. There were significant differences in bacterial community structure between the root epidermis and endophytic, rhizosheath, rhizosphere soil, and the sum of relative abundance of the dominant bacterial populations Actinobacteria and Proteobacteria was 73.9% in the root epidermis. Different from bacterial community structure, the community structure of root epidermis fungi was similar to endophytic, but significantly different from rhizosheath and rhizosphere soil. We suggest that the root epidermis can act as the interface between the host plant root and the external soil environment. This study will provide theoretical and technical guidance for the isolation of plant rhizosheath and the study of microorganisms in it.