Regulation of tissue-specific nonhost resistance by the circadian clock in plants

2022 Fiscal Year Final Research Report

• Project/Area Number: 19K06057
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 39040:Plant protection science-related
• Research Institution: Fukui Prefectural University
• Principal Investigator: Ishikawa Atsushi 福井県立大学, 生物資源学部, 教授 (70264687)
• Co-Investigator(Kenkyū-buntansha): 仲下 英雄 福井県立大学, 生物資源学部, 教授 (70280724)
• Project Period (FY): 2019-04-01 – 2023-03-31
• Keywords: シロイヌナズナ / イネいもち病菌 / 非宿主抵抗性 / 組織特異性 / 概日時計 / CCA1

Outline of Final Research Achievements

Nonhost resistance (NHR) is the most robust and durable resistance in plants, but its spatiotemporal regulation is poorly understood. The circadian clock functions in a tissue-specific manner and regulates individual physiological processes in plants. Using mutant and RNA-seq analyses, we revealed a role of CCA1 in tissue-specific and time-of-day-specific regulation of NHR to Pyricularia oryzae in Arabidopsis. Targeted perturbation of CCA1 function in epidermis compromised time-of-day-specific regulation of NHR to P. oryzae in Arabidopsis. RNA-seq analysis showed that P. oryzae inoculation alters the transcriptome in pen2 plants and identified PMR5 as a candidate gene of direct targets of CCA1. Time-of-day-specific penetration resistance to P. oryzae was reduced in Arabidopsis pen2 pmr5 mutant plants. These findings suggest that epidermal CCA1 and PMR5 contribute to the establishment of time-of-day-specific NHR to P. oryzae in Arabidopsis.

Free Research Field

植物保護科学

Academic Significance and Societal Importance of the Research Achievements

本研究により、シロイヌナズナのイネいもち病菌に対する非宿主抵抗性においては、概日時計CCA1が葉の表皮細胞特異的にPMR5 遺伝子の発現を制御することにより非宿主抵抗性を組織特異的かつ時間特異的に制御していることが示唆された。この成果は、時刻および植物組織を選んで植物防除の効果を最大限引き出す技術（組織特異的な概日時計を標的とした農薬の開発および遺伝子組み換え作物の創出等）の開発につながると期待される。