Molecular mechanisms of disease or plant immune responses by novel effector IPPTs from plant pathogenic bacteria

2022 Fiscal Year Final Research Report

• Project/Area Number: 19K15843
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 39040:Plant protection science-related
• Research Institution: Nagahama Institute of Bio-Science and Technology
• Principal Investigator: Kondo Machiko 長浜バイオ大学, バイオサイエンス学部, 助教 (40645975)
• Project Period (FY): 2019-04-01 – 2023-03-31
• Keywords: 植物病原細菌 / エフェクター / イネ / 免疫 / 病徴

Outline of Final Research Achievements

The rice-avirulent strain N1141 strain of the plant pathogenic bacteria Acidovorax avenae causes plant immunity including hypersensitive response cell death in rice, while K1 strain causes disease in rice. In this study, we revealed that T3SS effector IPPT of N1141 strain is involved in the induction of hypersensitive response accompanied by DNA fragmentation in rice and IPPT of K1 strain is involved in manifestation of disease symptoms in rice. IPPTs of N1141 or K1 translocated to rice cells equally and the enzyme active site mutant of IPPT from N1141 induced hypersensitive response cell death in rice. These data showed that induction of rice hypersensitive response cell death by IPPT from N1141 unaffected by secretion and enzyme activity. Thus, Novel effector IPPTs identified from A. avenae function in establishment of infection in host plants and induction of immunity in non-host plants.

Free Research Field

植物分子生理学、農芸化学、植物病理学、植物免疫学

Academic Significance and Societal Importance of the Research Achievements

植物の免疫や病気に関する研究はシロイヌナズナを用いた研究などが中心で、イネの細菌病の研究はあまり進んでいない。本研究によって褐条病細菌A. avenaeのIPPTタンパク質はイネの過敏感細胞死などの免疫誘導と病徴発現の両方に関与する宿主特異性キーエフェクターであることが明らかとなり、この分子機構の解明はイネの免疫システムや病徴発現機構を明らかにするための足掛かりとなるだろう。今後、植物の免疫システムや病徴発現機構の解明により、関連する因子をターゲットとした新しい農薬の開発や病害抵抗性品種の作出につながると考えられる。