Metagenomic analyses of the viruses detected in mycorrhizal fungi and their host orchid.
Metagenomic analyses of the viruses detected in mycorrhizal fungi and their host orchid.
复制标题
在菌根真菌及其宿主兰花中检测到的病毒的宏基因组分析。
DOI：
10.1007/978-1-4939-7683-6_12
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发表时间：
2018
期刊：
影响因子：
--
通讯作者：
Koda Y.
中科院分区：
文献类型：
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作者：
Shimura H.;Masuta C.;Koda Y.
在自然界中，菌根与土传真菌的结合是兰科植物不可或缺的。兰花细胞中相容的内生菌根真菌的真菌结构在细胞中被消化，作为营养供应给兰花。由于兰花种子缺乏萌发的储备，它们从种子萌发开始就通过菌根的形成不断接受营养，直到芽发育（叶子）并成为光合自养。所有兰花种子的萌发都需要真菌的帮助，而真菌与兰花之间的这种特殊的共生关系在很长的进化历史中就已经形成。我们研究了兰花与菌根真菌之间的相互作用，并利用下一代测序（NGS）技术进行了转录组分析（RNAseq）。从自然生长的植物中分离的兰花RNA可能被来自兰花细胞中的菌根真菌的RNA污染。为了避免这种污染，我们在此制备了无菌发芽的兰花植物（即，无真菌植物）连同纯培养的真菌分离物和田间生长的兰花样品。在从兰花和真菌组织制备的cDNA文库中，我们发现，partitivirus样序列在兰花和其菌根真菌中是共同的。这些partitivirus-like序列密切相关的系统发育分析，这表明，通过特定关系的兰花和其相关的真菌的祖先病毒之间的两种生物体的传输发生。
In nature, mycorrhizal association with soilborne fungi is indispensable for orchid families. Fungal structures from compatible endo-mycorrhizal fungi in orchid cells are digested in cells to be supplied to orchids as nutrition. Because orchid seeds lack the reserves for germination, they keep receiving nutrition through mycorrhizal formation from seed germination until shoots develop (leaves) and become photoautotrophic. Seeds of all orchid species surely geminate with the help of their own fungal partners, and this specific partnership has been acquired for a long evolutional history between orchids and fungi.We have studied the interactions between orchids and mycorrhizal fungi and recently conducted transcriptome analyses (RNAseq) by a next-generation sequencing (NGS) approach. It is possible that orchid RNA isolated form naturally grown plants is contaminated with RNAs derived from mycorrhizal fungi in the orchid cells. To avoid such contamination, we here prepared aseptically germinated orchid plants (i.e., fungus-free plants) together with a pure-cultured fungal isolate and field-growing orchid samples. In the cDNA library prepared from orchid and fungal tissues, we found that partitivirus-like sequences were common in an orchid and its mycorrhizal fungus. These partitivirus-like sequences were closely related by a phylogenetic analysis, suggesting that transmission of an ancestor virus between the two organisms occurred through the specific relation of the orchid and its associated fungus.