Köhler Michael, Castro Sánchez-Bermejo Pablo, Hähn Georg, Ferlian Olga, Eisenhauer Nico, Wubet Tesfaye, Haider Sylvia, Bruelheide Helge
Institute of Biology/Geobotany and Botanical Garden Martin Luther University Halle-Wittenberg Halle (Saale) Germany.
German Centre for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig Leipzig Germany.
Ecol Evol. 2025 Jul 17;15(7):e71691. doi: 10.1002/ece3.71691. eCollection 2025 Jul.
Fungal endophyte communities are mainly driven by host plant identity and geographic location. However, little is known about interactions between endophytes and characteristics of the host plant such as leaf functional traits, which vary both among and within host species. Previous studies focused on a limited number of host plant species and did not control for varying conditions in the host's neighborhood, which affect leaf functional traits and, in turn, might affect fungal endophyte communities. Using a tree diversity experiment in which all trees grow under standardized conditions, we were able to assess the contributions of host tree identity, host neighborhood species richness, and host community composition as well as the variation of leaf traits caused by these factors on taxonomic richness and community composition of foliar fungal endophytes. We used next-generation amplicon sequencing to analyze the fungal endophyte community and visible-near infrared spectrometry data to predict the mean values and the intra-individual variation of leaf traits in individual trees. We found both mean trait values and intra-individual trait variation to have significant effects on endophyte richness. Mean trait values of leaf dry matter content, leaf carbon, leaf nitrogen, and leaf carbon-to-nitrogen ratio exhibited negative effects on endophyte richness, whereas specific leaf area and leaf phosphorus content increased endophyte richness. Additionally, intra-individual leaf-trait variation generally had positive effects on richness. Overall endophyte community composition was influenced by mean leaf dry matter content and specific leaf area. Ascomycota were influenced by the specific leaf area, whereas Basidiomycota responded to leaf dry matter content. We demonstrate that functional leaf traits affect foliar endophyte communities, with positive diversity effects of host leaf nutrients that are essential, and likely limiting, for fungal endophytes. Although our study emphasizes the role of leaf traits in shaping fungal communities, we also acknowledge that these dynamic interactions could lead to traits being influenced by microbes through microbe-plant interactions.
真菌内生菌群落主要受宿主植物种类和地理位置的驱动。然而，对于内生菌与宿主植物特征（如叶片功能性状）之间的相互作用却知之甚少，这些特征在宿主物种之间和内部都会有所不同。以往的研究集中在有限数量的宿主植物物种上，没有控制宿主周围环境的变化条件，而这些条件会影响叶片功能性状，进而可能影响真菌内生菌群落。通过一项树木多样性实验，所有树木都在标准化条件下生长，我们能够评估宿主树种身份、宿主邻域物种丰富度和宿主群落组成的贡献，以及这些因素导致的叶片性状变化对叶部真菌内生菌的分类丰富度和群落组成的影响。我们使用下一代扩增子测序来分析真菌内生菌群落，并利用可见 - 近红外光谱数据来预测单株树木叶片性状的平均值和个体内变异。我们发现叶片性状的平均值和个体内性状变异均对内生菌丰富度有显著影响。叶片干物质含量、叶片碳、叶片氮和叶片碳氮比的平均性状值对内生菌丰富度有负面影响，而比叶面积和叶片磷含量则增加了内生菌丰富度。此外，个体内叶片性状变异通常对丰富度有积极影响。总体内生菌群落组成受叶片干物质含量平均值和比叶面积的影响。子囊菌受比叶面积的影响，而担子菌则对叶片干物质含量有响应。我们证明功能性叶片性状会影响叶部内生菌群落，宿主叶片养分对真菌内生菌至关重要且可能具有限制作用，其具有积极的多样性效应。尽管我们的研究强调了叶片性状在塑造真菌群落中的作用，但我们也承认这些动态相互作用可能导致性状通过微生物 - 植物相互作用受到微生物的影响。
