Study to elucidate molecular mechanisms involved in orchid-mycorrhiza interaction

2019 Fiscal Year Final Research Report

• Project/Area Number: 17K19253
• Research Category: Grant-in-Aid for Challenging Research (Exploratory)
• Allocation Type: Multi-year Fund
• Research Field: Agricultural and Environmental Biology and related fields
• Research Institution: Hokkaido University
• Principal Investigator: Shimura Hanako 北海道大学, 農学研究院, 講師 (20507230)
• Project Period (FY): 2017-06-30 – 2020-03-31
• Keywords: ラン / 菌根菌 / 種子発芽 / マイコウイルス

Outline of Final Research Achievements

Plants in the family Orchidaceae depend on mycorrhizal fungi for seed germination and following seedling development, but little is known about the molecular mechanisms involved in the orchid-fungal interactions. This study aimed to clarify the molecular mechanism involved in the establishment and maintenance of mycorrhizal relationships by using various orchid mycorrhizal fungi with different ability to induce germination. As a factor related to the germination ability, it was suggested that the kind of partitivirus infecting the fungus and the involvement of endornavirus and megabirnavirus. RNAseq analysis using protocorms obtained with or without fungal inoculation was conducted to know the gene expression involved in symbiotic germination, and it was suggested that the defense response-related genes and sugar transport-related genes were involved in regulation of mycorrhizal interaction with fungi.

Free Research Field

植物病理学、植物生理学

Academic Significance and Societal Importance of the Research Achievements

植物界で最も多様性があるとされるラン科植物がもつ特殊な共生関係はランの生存に必須であり、進化の過程でも失われずに維持されてきた重要なメカニズムである。しかし、その制御に関わる要因については研究が進んでいない。本研究では、共生関係を制御するメカニズムの一因として、菌根菌に感染するウイルスや共生特異的に発現する遺伝子を示唆することができた。さらなる解明により、植物と菌の相互作用に及ぼす内在ウイルスの存在意義を明らかにし、ランと菌根菌の進化学に新たな研究領域を開拓することも期待される。