Table_1_Leaf and Root Endospheres Harbor Lower Fungal Diversity and Less Complex Fungal Co-occurrence Patterns Than Rhizosphere.DOCX

Plant-associated microbiomes are key determinants of host-plant fitness, productivity, and function. However, compared to bacterial community, we still lack fundamental knowledge concerning the variation in the fungal microbiome at the plant niche level. In this study, we quantified the fungal communities in the rhizosphere soil, as well as leaf and root endosphere compartments of a subtropical island shrub, Mussaenda kwangtungensis, using high-throughput DNA sequencing. We found that fungal microbiomes varied significantly across different plant compartments. Rhizosphere soil exhibited the highest level of fungal diversity, whereas the lowest level was found in the leaf endosphere. Further, the fungal communities inhabiting the root endosphere shared a greater proportion of fungal operational taxonomic units (OTUs) with rhizosphere communities than with leaf fungal endophyte communities, despite significant separation in community structure between the two belowground compartments. The fungal co-occurrence networks in the three compartments of M. kwangtungensis showed scale-free features and non-random co-occurrence patterns and matched the topological properties of small-world and evidently modular structure. Additionally, the rhizosphere network was more complex and showed higher centrality and connectedness than the leaf and root endosphere networks. Overall, our findings provide comprehensive insights into the structural variability, niche differentiation, and co-occurrence patterns in the plant associated fungal microbiome.

植物相关微生物组（plant-associated microbiomes）是决定宿主植物适合度、生产力与功能的关键因素。然而，相较于细菌群落，我们对于植物生态位水平下真菌微生物组（fungal microbiome）的变异仍缺乏基础认知。本研究借助高通量DNA测序技术，对亚热带岛屿灌木广东玉叶金花（Mussaenda kwangtungensis）的根际土壤、叶片内生境以及根系内生境分区中的真菌群落进行了定量分析。研究发现，真菌微生物组在不同植物分区中存在显著差异。根际土壤的真菌多样性水平最高，叶片内生境则最低。进一步而言，尽管两个地下分区的群落结构存在显著分化，但栖息于根系内生境的真菌群落与根际群落共享的真菌操作分类单元（operational taxonomic units, OTUs）比例，高于其与叶片内生真菌群落共享的比例。广东玉叶金花三个分区的真菌共现网络均呈现无标度特征与非随机共现模式，且符合小世界拓扑特性与显著的模块化结构。此外，相较于叶片与根系内生境网络，根际网络更为复杂，且具有更高的中心性与连通性。综上，本研究结果为植物关联真菌微生物组的结构变异性、生态位分化及共现模式提供了全面的认知视角。