Eukaryote-associated microbiomes vary across host taxa and environments but the key factors underlying their diversity and structure in fungi are still poorly understood. Here we determined the structure of bacterial communities in fungal fruitbodies in relation to the main chemical characteristics in ectomycorrhizal (EcM) and saprotrophic (SAP) mushrooms as well as in the surrounding soil. Our analyses revealed significant differences in the structure of endofungal bacterial communities across fungal phylogenetic groups and to a lesser extent across fungal guilds. These variations could be partly ascribed to differences in fruitbody chemistry, particularly the carbon-to-nitrogen ratio and pH. Fungal fruitbodies appear to represent nutrient-rich islands that derive their microbiome largely from the underlying continuous soil environment, with a larger overlap of operational taxonomic units observed between SAP fruitbodies and the surrounding soil, compared with EcM fungi. In addition, bacterial taxa involved in the decomposition of organic material were relatively more abundant in SAP fruitbodies, whereas those involved in release of minerals were relatively more enriched in EcM fruitbodies. Such contrasts in patterns and underlying processes of the microbiome structure between SAP and EcM fungi provide further evidence that bacteria can support the functional roles of these fungi in terrestrial ecosystems.

中文翻译：

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子实体化学是跨真菌群和系统发育群的真菌内细菌群落结构的基础。


真核生物相关微生物群因宿主分类群和环境而异，但真菌中其多样性和结构背后的关键因素仍然知之甚少。在这里，我们确定了真菌子实体中细菌群落的结构与外生菌根（EcM）和腐生（SAP）蘑菇以及周围土壤中主要化学特征的关系。我们的分析揭示了不同真菌系统发育群体的真菌内细菌群落结构的显着差异，不同真菌群之间的真菌内细菌群落结构存在显着差异。这些差异部分归因于子实体化学的差异，特别是碳氮比和 pH 值。真菌子实体似乎代表了营养丰富的岛屿，其微生物组主要来自底层的连续土壤环境，与 EcM 真菌相比，在 SAP 子实体和周围土壤之间观察到的操作分类单元有更大的重叠。此外，参与有机物质分解的细菌类群在SAP子实体中相对丰富，而参与矿物质释放的细菌类群在EcM子实体中相对丰富。 SAP 和 EcM 真菌之间微生物组结构的模式和潜在过程的这种对比进一步证明细菌可以支持这些真菌在陆地生态系统中的功能作用。