Ectomycorrhiza-associated bacteria, especially endofungal bacterial microbiota (EBM) in the fruiting body, play important roles in driving the establishment and function of ectomycorrhizae. However, the influence of ectomycorrhizal fungus bolete identity on their EBM is still unclear. We analysed the EBM of three different bolete fruiting body species on Thousand Island Lake, including Tylopilus felleus, Tylopilus areolatus and Boletus queletii, and compared them with their corresponding mycosphere soil bacterial microbiota by high-throughput sequencing. The EBM was classified into Bacillus, Pseudomonas, Burkholderia and Stenotrophomonas genera. Proteobacteria, Bacteroidetes and Acidobacteria were predominant in the EBM of bolete fruiting bodies as well as their mycosphere soil, while Firmicutes was significantly higher in the EBM. Moreover, the core microbiome (342 operational taxonomic units) of the EBM was shared among the three bolete fungal species. The relative abundances of gene families related to cell cycle control and nucleotide, coenzyme and lipid metabolism were significantly higher in the EBM than in the corresponding mycosphere soil bacterial microbiota, but there was no difference among the three different boletes. The results suggested that the host identity of ectomycorrhizal fungus boletes could affect the EBM, which might be mainly due to the selection of host fungi for the different functional EBM needed.

中文翻译：

---

外生菌根真菌牛肝菌特性对内生菌群落组合的影响

外生菌根相关细菌，尤其是子实体中的内真菌菌群（EBM），在驱动外生菌根的建立和功能方面发挥着重要作用。然而，外生菌根真菌牛肝菌特性对其EBM的影响仍不清楚。我们分析了千岛湖三种不同的牛肝菌子实体物种的EBM，包括Tylopilus faireus 、Tylopilus areolatus和Boletus queletii，并通过高通量测序将它们与相应的菌圈土壤细菌微生物群进行了比较。EBM分为芽孢杆菌属、假单胞菌属、伯克霍尔德菌属和窄食单胞菌属。变形菌门、拟杆菌门和酸杆菌门在牛肝菌子实体及其菌圈土壤的 EBM 中占优势，而厚壁菌门在 EBM 中显着更高。此外，EBM 的核心微生物组（342 个操作分类单元）在三种牛肝菌真菌物种之间共享。EBM中与细胞周期控制和核苷酸、辅酶和脂质代谢相关的基因家族的相对丰度显着高于相应的真菌圈土壤细菌微生物群，但三种不同牛肝菌之间没有差异。结果表明，外生菌根真菌牛肝菌的宿主身份可能会影响EBM，这可能主要是由于为所需的不同功能EBM选择了宿主真菌。