Molecular mechanism of rice blast resistance acquisition by SnRK1 involved in plant nutrition metabolism

2020 Fiscal Year Final Research Report

• Project/Area Number: 17K07678
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Plant protection science
• Research Institution: National Agriculture and Food Research Organization
• Principal Investigator: Hayashi Nagao 国立研究開発法人農業・食品産業技術総合研究機構, 生物機能利用研究部門, 再雇用職員 (90391557)
• Co-Investigator(Kenkyū-buntansha): 井上 晴彦 国立研究開発法人農業・食品産業技術総合研究機構, 生物機能利用研究部門, 上級研究員 (10435612)
• Project Period (FY): 2017-04-01 – 2021-03-31
• Keywords: 育種学 / 菌類 / シグナル伝達 / 植物 / 圃場抵抗性

Outline of Final Research Achievements

The rice blast resistance gene pi21, derived from the upland rice variety Sensho, confers stable resistance to leaf blast in rice. pi21-dependent blast resistance was significantly reduced when SnRK1, a factor that interacts with pi21, was repressed (RNAi) in rice plants carrying pi21. In experiments in which resistant and susceptible cultivars were inoculated with blast fungi and allowed to take up C13 and N14 radioisotopes, carbon flow was unaffected. On the other hand, for nitrogen, the nitrogen signals were observed on the leaf sheath side around the blast lesions, especially strong signals were observed in the susceptible variety. To confirm this phenomenon, we used fluorescently labeled infected rice plant and observed signals extending outward from the blast lesions in both resistant and susceptible varieties. This suggests that the blast fungus acquires some nutrients by extending its hyphe not only to the lesion but also to the area around the lesion.

Free Research Field

植物微生物相互作用

Academic Significance and Societal Importance of the Research Achievements

圃場抵抗性であるpi21の抵抗性機構を明らかにするために、タンパク質の相互作用因子に着目し本研究を行った。pi21はSnRK1と相互作用するが、SnRK1の特性から栄養との関連性を検証することで、いもち病圃場抵抗性は窒素栄養と深く結びついていることを明らかにした。古くからいもち病罹病には、窒素栄養が深く関わっているとされており、その分子生物学的な一端を明らかにしたことは意義深い。同時に、pi21抵抗性が今後広く普及するために科学的な知見として利用される。