Comparative Analysis of Rhizosphere Microbial Community Diversity and Composition of Common Reed and Common Seepweed on Chenier Islands

The Chenier Islands are depositional areas within intertidal zones, characterized by unique soil textures and distinctive environmental conditions that shape specific vegetation distribution patterns. However, the adaptive mechanisms of Phragmites australis common reed and Suaeda salsa common seepweed two prevalent plant species in this region to saline stress environments, as well as the composition and functional characteristics of their rhizosphere microbial communities, remain largely unclear. In this study, rhizosphere soil samples were collected from both common reed and common seepweed. High throughput sequencing techniques were employed to investigate rhizosphere microbial communities' composition and functional traits. The results indicated that the dominant microbial phyla in the rhizosphere of both species included Proteobacteria, Bacteroidota, Chloroflexota, and Actinomycetota. While no significant differences were observed in alpha diversity indices, Principal Coordinates Analysis PCoA and PERMANOVA demonstrated substantial differences in microbial community composition between the two plant species. Furthermore, results from LEfSe analysis, along with functional predictions using PICRUSt2 and FAPROTAX, suggest that functional redundancy is prevalent in the rhizosphere environments of both species. This study identifies a rhizosphere microbial community assembly pattern characterized by "structural differentiation but functional convergence," offering valuable insights into the mechanisms underlying vegetation adaptation to saline stress on the Chenier Islands.