Data_Sheet_1_Elucidating the endophytic bacterial and fungal community composition and diversity in the tree fern Alsophila spinulosa through meta-amplicon sequencing.docx

Plant tissues harbor abundant endophytes, which are crucial for plant growth. Endophytes present in Alsophila spinulosa, which is enriched with medicinal components, have not been isolated and characterized yet. Here we employed meta-amplicon sequencing to identify endophytic species and examined their diversity in the leaves, petioles, roots and stems of A. spinulosa. Our findings revealed 1,247 operational taxonomic units (OTUs) for endophytic bacteria across 210 species and 476 OTUs for endophytic fungi across 222 species. Alpha diversity analysis showed the highest endophytic bacterial diversity in A. spinulosa roots, whereas fungal diversity was similar across the leaf, petiole and root tissues. Fungal diversity in the leaves and petioles was markedly higher than that in the stems. Furthermore, beta diversity analysis revealed similarities in the endophytic bacterial and fungal compositions between the leaves and petioles, whereas the compositions in roots and stems considerably differed from those in the leaves and petioles. At the genus level, the predominant endophytic bacteria were Methylobacterium-Methylorubrum and Pseudomonas, whereas the predominant endophytic fungi were Cutaneotrichosporon and Pseudofabraea. Linear discriminant analysis effect size revealed characteristic endophytic bacterial genera specific to each tissue type and characteristic endophytic fungal genera specifically in the leaves, petioles and roots. The co-occurrence network analysis indicated that the complexity of endophyte networks was the highest in the leaves and the lowest in the stems of A. spinulosa. Overall, this study elucidates the distribution patterns of endophytes in A. spinulosa across various tissues, offering valuable microbial resources for the development of natural products for medicinal application.

植物组织中定殖着大量内生菌，这类微生物对植物生长具有关键作用。富含药用成分的桫椤（Alsophila spinulosa），其内生菌至今尚未被分离与鉴定。本研究采用宏扩增子测序（meta-amplicon sequencing）技术鉴定内生菌物种，并分析了桫椤叶片、叶柄、根与茎中的内生菌多样性。研究结果显示，内生细菌共获得1247个操作分类单元（operational taxonomic units，OTU），隶属于210个物种；内生真菌共获得476个OTU，隶属于222个物种。α多样性（alpha diversity）分析结果表明，桫椤根内的细菌内生菌多样性最高；而真菌多样性在叶片、叶柄与根组织中无显著差异，且叶片与叶柄中的真菌多样性显著高于茎部。此外，β多样性（beta diversity）分析显示，叶片与叶柄的内生细菌和真菌群落组成具有较高相似性，而根与茎的群落组成与叶片、叶柄存在显著差异。在属水平上，优势内生细菌为甲基杆菌-甲基红球菌属（Methylobacterium-Methylorubrum）与假单胞菌属（Pseudomonas）；优势内生真菌为节毛孢子菌属（Cutaneotrichosporon）与假粉孢属（Pseudofabraea）。线性判别分析效应量（Linear discriminant analysis effect size，LEfSe）分析发现，各组织类型均存在特异性的内生细菌属，而叶片、叶柄与根中分别存在特异性的内生真菌属。共现网络分析结果表明，桫椤叶片的内生菌网络复杂度最高，茎部最低。综上，本研究阐明了桫椤不同组织中内生菌的分布模式，可为药用天然产物的开发提供宝贵的微生物资源。