Institute for Sustainable Plant Protection, CNR, Strada delle Cacce 73, 10135, Torino and V. le Mattioli 25, 10125, Torino, Italy.
Department of Life Sciences and Systems Biology, University of Torino, V. le Mattioli 25, 10125, Torino, Italy.
Sci Rep. 2022 Jun 30;12(1):11013. doi: 10.1038/s41598-022-15154-1.
Plants harbor in their external surfaces and internal tissues a highly diverse and finely structured microbial assembly, the microbiota. Each plant compartment usually represents a unique ecological niche hosting a distinct microbial community and niche differentiation, which may mirror distinct functions of a specialized microbiota, has been mainly investigated for bacteria. Far less is known for the fungal components of the plant-associated microbiota. Here, we applied a metabarcoding approach to describe the fungal assemblages in different organs of Vaccinium myrtillus plants (Ericaceae) collected in a subalpine meadow in North-West Italy, and identified specific taxa enriched in internal tissues of roots, stems, leaves and flowers. We also traced the distribution of some important fungi commonly associated with plants of the family Ericaceae, namely the ericoid mycorrhizal (ErM) fungi and the dark septate endophytes (DSE), both playing important roles in plant growth and health. Operational taxonomic units attributed to established ErM fungal species in the genus Hyaloscypha and to DSE species in the Phialocephala-Acephala applanata complex (PAC) were found in all the plant organs. Mycorrhizal fungi are thought to be strictly associated with the plant roots, and this first observation of ErM fungi in the above-ground organs of the host plant may be explained by the evolutionary closeness of ErM fungi in the genus Hyaloscypha with non mycorrhizal fungal endophytes. This is also witnessed by the closer similarities of the ErM fungal genomes with the genomes of plant endophytes than with those of other mycorrhizal fungi, such as arbuscular or ectomycorrhizal fungi.
植物的外部表面和内部组织中蕴藏着高度多样化和精细结构的微生物组合，即微生物群落。每个植物隔室通常代表一个独特的生态位，容纳着独特的微生物群落和生态位分化，这可能反映了专门化微生物群落的不同功能，主要针对细菌进行了研究。对于与植物相关的微生物群落中的真菌成分，人们了解得要少得多。在这里，我们应用了一种代谢组学方法来描述在意大利西北部一个亚高山草甸中收集的越桔属（杜鹃花科）不同器官中的真菌组合，并确定了在根、茎、叶和花的内部组织中丰富的特定分类群。我们还追踪了一些与杜鹃花科植物常见相关的重要真菌的分布，即菌根（ErM）真菌和暗隔内生真菌（DSE），它们在植物生长和健康中都起着重要作用。在属 Hyaloscypha 中被归为已建立的 ErM 真菌物种的分类单元和 Phialocephala-Acephala applanata 复合体（PAC）中的 DSE 物种，在所有植物器官中都有发现。菌根真菌被认为与植物根系严格相关，而在宿主植物地上器官中首次观察到 ErM 真菌，这可能是由于属 Hyaloscypha 中的 ErM 真菌与非菌根真菌内生菌在进化上的紧密联系。这也可以从 ErM 真菌基因组与植物内生菌基因组的相似性比与其他菌根真菌（如丛枝菌根真菌或外生菌根真菌）的基因组的相似性更紧密来证明。
