Elucidation of the molecular mechanism of symbiotic incompatibility via type III secretion system and plant immunity

2022 Fiscal Year Final Research Report

• Project/Area Number: 19K05760
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 38020:Applied microbiology-related
• Research Institution: Obihiro University of Agriculture and Veterinary Medicine (2020-2022); Tohoku University (2019)
• Principal Investigator: Sugawara Masayuki 帯広畜産大学, 畜産学部, 准教授 (90742776)
• Project Period (FY): 2019-04-01 – 2023-03-31
• Keywords: 根粒菌 / 3型タンパク質分泌機構 / エフェクター / 共生不和合性

Outline of Final Research Achievements

In order to elucidate the molecular mechanism of symbiotic incompatibility with leguminous plants mediated by rhizobial type III secretory effector NopP, we investigated changes in gene expression in soybean roots induced by incompatible NopP. As a result, the genes involved in oxidative stress, cell wall construction and maintenance, and multiple pathogenic responses were significantly upregulated. In addition, this study revealed that the type III secretion system of soybean rhizobia is involved in the symbiotic incompatibility with several species of the Desmodieae, including Lespedeza cuneata. On the other hand, it was suggested that unknown incompatibility factors other than the type III secretion system are involved in the incompatibility of rhizobia isolated from Lespedeza nodules to soybean.

Free Research Field

応用微生物学

Academic Significance and Societal Importance of the Research Achievements

根粒菌とマメ科植物の共生相互作用において、3型分泌エフェクターと植物免疫系を介して特異性が決定される例が本研究期間内において続々と報告され、根粒菌エフェクターによる宿主特異性の決定が進化の過程で広く確立してきたことが窺える。したがって、本研究の成果は根粒菌と植物の共進化を紐解く重要な手がかりとなり学術的な意義は高い。またマメ科作物の生産性向上と環境負荷低減に寄与可能な技術の構築において、共生不和合性を応用することで優良な根粒菌の競合性を高めることが期待され、本成果は社会的にも有意義な知見を与えるものであると考えられる。