Orchid mycorrhizal fungi and ascomycetous fungi in epiphytic Vanda falcata roots occupy different niches during growth and development
Orchid mycorrhizal fungi and ascomycetous fungi in epiphytic Vanda falcata roots occupy different niches during growth and development
复制标题
DOI：
10.1007/s00572-022-01089-y
复制
发表时间：
2022-07
期刊：
影响因子：
3.9
通讯作者：
Galih Chersy Pujasatria;Ikuo Nishiguchi;C. Miura;M. Yamato;H. Kaminaka
中科院分区：
文献类型：
--
作者：
Galih Chersy Pujasatria;Ikuo Nishiguchi;C. Miura;M. Yamato;H. Kaminaka
附生兰花通常生长在暴露的环境中，这可能导致其根系真菌群落结构与陆生兰花不同。直到最近，很少有研究已经进行，以显示在其自然生长地点的光合和附生兰花生长过程中的真菌群落结构。本研究以日本观赏兰种之一的镰形万代兰（Vanda falcata）为研究对象，对不同发育阶段的真菌群落结构进行了研究。扩增子测序分析表明，所有的发展阶段包含一个类似的真菌群落：子囊菌门占主导地位的社区，而三分之一的社区属于Basidiomycota.Rhizoctonia-like真菌，一个多系的担子菌类真菌在许多兰花形成菌根，甚至存在于一个较小的部分（约四分之一）相比，其他Basidiomycota成员。虽然子囊菌具有致病性，但两个从幼苗和成株植物中分离的Ceratobasidium菌株可以在体外启动种子萌发。结果还发现，菌根真菌的殖民化集中在一个部分的根，它直接附着在phorophyte树皮，而子囊菌分布在被，但从来没有殖民化皮层细胞。此外，附着在树皮上的根部分有更密集的外胚层通道细胞，这些细胞只被进一步渗透到皮层区域的菌根真菌定殖。因此，我们证实了一个过程，真菌进入的物理调节，以划分子囊菌和菌根真菌的结果在平衡的菌根共生在这种兰花。
Epiphytic orchids are commonly found in exposed environments, which plausibly lead to different root fungal community structures from terrestrial orchids. Until recently, few studies have been conducted to show the fungal community structure during the growth of a photosynthetic and epiphytic orchid in its natural growing site. In this study, theVanda falcata(commonly known asNeofinetia falcata), one of Japan’s ornamental orchids, was used to characterize the fungal community structure at different developmental stages. Amplicon sequencing analysis showed that all development stages contain a similar fungal community: Ascomycota dominate half of the community while one-third of the community belongs to Basidiomycota.Rhizoctonia-like fungi, a polyphyletic basidiomycetous fungal group forming mycorrhizas in many orchids, exist even in a smaller portion (around one-quarter) compared to other Basidiomycota members. While ascomycetous fungi exhibit pathogenicity, twoCeratobasidiumstrains isolated from young and adult plants could initiate seed germination in vitro. It was also found that the colonization of mycorrhizal fungi was concentrated in a part of the root where it directly attaches to the phorophyte bark, while ascomycetous fungi were distributed in the velamen but never colonized cortical cells. Additionally, the root parts attached to the bark have denser exodermal passage cells, and these cells were only colonized by mycorrhizal fungi that further penetrated into the cortical area. Therefore, we confirmed a process that physical regulation of fungal entry to partition the ascomycetes and mycorrhizal fungi results in the balanced mycorrhizal symbiosis in this orchid.