Exploring the structure and assembly of seagrass microbial communities in rhizosphere and phyllosphere.

Microbial community assembly and interactions are pivotal research areas within microbial ecology, yet relevant studies in seagrass rhizospheres and phyllosphere remain relatively scarce. In this study, we utilized high-throughput sequencing technology to investigate the microbial communities in different periods and microhabitats (rhizosphere and phyllosphere) of two seagrass species (Zostera marina and Phyllospadix iwatensis). Our findings suggest that microhabitats have a more pronounced impact on the composition of seagrass-associated microbial communities compared to periods and species. Further investigations reveal that the phyllosphere microbial community exhibits a more intricate co-occurrence network and interactions than the rhizosphere microbial community. Keystone taxa show distinct functional roles in different microhabitats of seagrasses. Additionally, we observed that differences in seagrass microhabitats influence community assembly, with the rhizosphere microbial community being more influenced by deterministic processes (heterogeneous selection) compared to the phyllosphere. These findings contribute to our understanding of the intricate interactions between seagrasses and their associated microbial communities, providing valuable insights into their distribution patterns and microhabitat preferences.IMPORTANCEStudying the community structure and assembly of different microhabitats in seagrass beds contributes to revealing the complexity and dynamic processes of seagrass ecosystems. In the rhizosphere microhabitat of seagrasses, microbial communities may assist in disease resistance or enhance nutrient uptake efficiency in seagrasses. On the other hand, in the microhabitat on the surface of seagrass blades, microorganisms may be closely associated with the physiological functions and nutrient cycling of seagrass blades. Therefore, understanding the structure and assembly mechanisms of rhizosphere and phyllosphere microbial communities is crucial for exploring the interactions between seagrass and microbial communities, as well as for enhancing our comprehension of the stability and resilience of seagrass bed ecosystems.