Influence of plant diversity on bacterial rare and abundant subcommunities in rhizosphere soil

<bold>Objective</bold> Plants maintain close relationships with microorganisms in their growth environment，and they form a plant-microorganism symbiotic system.Plants are key drivers in shaping soil microbial communities，an in-depth understanding of the impact of plants on soil microbial communities is of great ecological significance.This study aims to systematically investigate the effects of plant species composition and diversity on soil bacterial communities by analyzing changes in community structure and characteristics of co-occurrence networks of rare and abundant subcommunities. <bold>Method</bold> Twelve common wetland plants were selected as research materials.A pot experiment was conducted using no-plant control（CK）and random combinations of plant species to create diversity levels of 1，2，4，and 8 species.Subsequently，rhizosphere soil samples were collected during the plant’s reproductive period.High-throughput sequencing technology was used to obtain bacterial 16S rDNA gene sequences，and bioinformatics techniques were combined to analyze the community structure and diversity characteristics of the overall soil bacteria，rare subcommunities，and abundant subcommunities. <bold>Result</bold> Under different plant species and diversity levels，α diversity trends of the overall bacterial community and rare subcommunities were consistent，while differences in abundant subcommunities across treatments were generally not significant.Plant species had a greater impact on shifts in the structure of rare bacterial subcommunities compared to abundant subcommunities.The magnitude of community structure shifts in rare subcommunities increased with rising plant diversity，whereas that of abundant subcommunities initially increased and then stabilized.In addition，increased plant diversity significantly enhanced the complexity and interaction strength of the co-occurrence networks in both the overall bacterial community and rare subcommunities. <bold>Conclusion</bold> Plant diversity has a higher impact on soil bacterial rare subcommunities than on abundant subcommunities，indicating that plant diversity likely influences the structure and function of the overall bacterial community primarily by regulating the composition and dynamics of rare subcommunities.