The dominant role of microbial groups in the community assembly process of phyllospheric microorganisms

Abstract:

[Background] The research on the community assembly of phyllospheric microorganisms is of great significance to clarify the formation and maintenance mechanism of microbial diversity, while it presents slow progress. [Objective] To explore the community assembly processes of phyllospheric microorganisms in garden plants and determine the main influencing factors. [Methods] Three species of garden plants located within a 50-m radius from the lower edge of the Cangshan National Nature Reserve in Dali were selected, and leaves of varying sizes in the same orientation were collected. High-throughput sequencing and the theoretical model of community assembly were employed to analyze the community assembly process of phyllospheric microorganisms on different scales, including the entire microorganism community, different plant species, different leaf sizes, and different microbial groups. [Results] The community assembly processes of all the phyllospheric microorganisms, different plant species, and different leaf sizes were similar. That is, they were all dominated by the homogenous selection of deterministic process. However, there was a distinction in the community assembly processes between bacteria and fungi. Specifically, the community assembly of phyllospheric fungi and phyllospheric bacteria were dominated by the drift of stochastic process and the homogenous selection of deterministic process, respectively. The generalized linear model analysis showed that plant species had a significant impact on the community assembly process of phyllospheric microorganisms. Particularly, the microbial groups and the combination of microbial groups and plant species had highly significant impacts on the community assembly process of phyllospheric microorganisms, while leaf size had an insignificant impact. [Conclusion] Therefore, microbial groups are the decisive factor in the community assembly process of phyllospheric microorganisms.

Key words:phyllospheric microorganisms;plant species;leaf size;high-throughput sequencing;community assembly process