Development of low arsenic rice with enhanced phytochelatin synthase activity by genome editing

2022 Fiscal Year Final Research Report

• Project/Area Number: 20K05778
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 38010:Plant nutrition and soil science-related
• Research Institution: National Agriculture and Food Research Organization
• Principal Investigator: Ishikawa Satoru 国立研究開発法人農業・食品産業技術総合研究機構, 農業環境研究部門, グループ長 (40354005)
• Co-Investigator(Kenkyū-buntansha): 安部 匡 国立研究開発法人農業・食品産業技術総合研究機構, 農業環境研究部門, 上級研究員 (70729201) ; 倉俣 正人 国立研究開発法人農業・食品産業技術総合研究機構, 農業環境研究部門, 主任研究員 (80826991)
• Project Period (FY): 2020-04-01 – 2023-03-31
• Keywords: ヒ素 / イネ / ファイトケラチン

Outline of Final Research Achievements

This study aimed to identify the amino acid required for arsenic (As)-induced phytochelatin synthase (OsPCS1) activity of rice and to produce low-As rice by enhancing the enzyme activity. DNA fragments with random mutations in the C-terminal region of OsPCS1 were introduced into recombinant yeast strains and screened for arsenic tolerance. We found that several yeast strains with mutated OsPCS1 showed higher tolerance to As stress than those with wild-type OsPCS1. The OsPCS1 enzyme from the obtained As-tolerant OsPCS1 clones was produced in E. coli cells and the amounts of phytochelatin (PCs) by arsenic addition were measured by LC-MS-MS. The results showed that there was some mutated OsPCS1 that synthesized higher amounts of PCs than wild-type OsPCS1. In the future, rice plants with enhanced OsPCS1 activity would be produced by genome editing, and the As concentration in such rice plants should be analyzed.

Free Research Field

植物栄養学

Academic Significance and Societal Importance of the Research Achievements

本研究はイネのファイトケラチン合成酵素のヒ素応答性に関して、活性化に必要なアミノ酸部位やヒ素とその他金属の認識応答性の違いを解明する研究につながる。さらにファイトケラチン合成酵素の機能強化はヒ素だけなく、カドミウム等の有害金属の作物可食部への蓄積を抑制することが可能になると思われる。