Influence of Plant Organs and Functional Traits on the Structure of Bacterial and Fungal Communities in Three Acer Species

Plants and the microorganisms living on their surfaces are an inseparable community that interacts with plant functional traits and influences plant growth, but the differences in microorganisms between plant organs and their relationship with plant functional traits have not been deeply explored. In this study, we used high-throughput sequencing to investigate the variation of microorganisms across different plant organs (leaves, twigs, trunks, and roots) of three species (Acer pictum subsp. mono, Acer tegmentosum, and Acer ukurunduense) in the Xiaoxing’an Mountains in Northeastern China and explored the relationship between microorganisms and plant functional traits. The results indicate that rhizosphere microorganisms have a high diversity. Plant organs explained 52.1% and 32.3% of the variations in bacterial and fungal community structures, respectively. The core microbiome consists of the phyla Proteobacteria and Actinobacteria in bacteria and the phyla Ascomycota and Basidiomycota in fungi. Plant functional traits such as specific leaf area and non-structural carbohydrates, as well as soil total carbon and total phosphorus content, were significantly correlated with microbial community composition. The results highlight that host plant organ characteristics are key drivers of variation in plant-associated microbial communities. By elucidating the regulatory role of host traits in microbiome assembly, our findings provide new mechanistic insights into plant–microbe interactions and ecological coexistence strategies.