Induction of hypersensitive response cell death by OsCPK8

2021 Fiscal Year Final Research Report

• Project/Area Number: 19K15844
• 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: HIRAI HIROYUKI 長浜バイオ大学, バイオサイエンス学部, プロジェクト特任助教 (70748847)
• Project Period (FY): 2019-04-01 – 2022-03-31
• Keywords: OsNAC4 / OsCPK8 / 過敏感細胞死

Outline of Final Research Achievements

Hypersensitive (HR) cell death with DNA degradation and loss of plasma membrane integrity is one of the programmed cell deaths of plants. We previously identified that phosphorylated protein OsCPK8 was signal transduction factor for inducing HR cell death in rice. However, downstream of OsCPK8 in rice HR cell death still unknown. To identify rice HR cell death-related genes downstream of OsCPK8, We performed transcriptome analysis during rice HR cell death using RNA-seq. Four genes were identified as HR cell death-related genes. Among the four genes, IREN gene which encodes a plant nuclease controls DNA degradation. The remaining three genes, OsHSP90, ESP1 and Fat genes are associated with loss of plasma membrane integrity.

Free Research Field

OsNAC4

Academic Significance and Societal Importance of the Research Achievements

植物免疫の中でも強力な免疫反応である過敏感細胞死の分子機構は不明な点が多かった。本研究は、この植物の過敏感細胞死分子機構についてイネを用いて解明を試みた。本研究において、OsCPK8の下流に存在するイネ過敏感細胞死関連因子として、OsNAC4・IREN・OsHSP90・ESP1・Fat遺伝子の5因子を同定した。この発見はイネ過敏感細胞死の更なる解明への足掛かりとなるものであると共に、他の植物の過敏感細胞死分子機構の解明に一役買えるものでもある。さらに、過敏感細胞死の分子機構が解明されれば、関連因子を標的とした新規農薬やゲノム編集技術による新規病害抵抗性品種の作出につながる可能性を秘めている。