Characterization of rice alpha-amylase genes governing grain quality and screening for transcription factors regulating their expression.

2017 Fiscal Year Final Research Report

• Project/Area Number: 15K07279
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Crop production science
• Research Institution: National Agriculture and Food Research Organization
• Principal Investigator: Yamakawa Hiromoto 国立研究開発法人農業・食品産業技術総合研究機構, 中央農業研究センター, 上級研究員 (10370537)
• Co-Investigator(Renkei-kenkyūsha): MITSUDA nobutaka 産業技術総合研究所, 生物プロセス研究部門, 主任研究員 (80450667)
• Project Period (FY): 2015-04-01 – 2018-03-31
• Keywords: イネ / 高温登熟 / 乳白粒 / 胚乳 / α-アミラーゼ / プロモーター / 転写調節因子

Outline of Final Research Achievements

Exposure of ripening rice caryopses to high temperature impairs their grain filling and produces low-quality chalky grains through imperfect filling with storage starch. Spatial expression pattern of starch-lytic α-amylase genes in the developing seeds as well as changes in grain appearance by ectopic overexpression of each of the genes revealed that expression of Amy1A, Amy3C and Amy3D was induced in the developing endosperm by the elevated temperature and that those isoforms degraded storage starch to produce the chalky grains. Screening of a yeast one-hybrid library consisting of rice transcription factors with a cis region in the Amy3C promoter identified bZIP61 as a candidate in regulation of its expression. Since overexpression of bZIP61 generated chalky grains, it would be a novel gene controlling grain quality.

Free Research Field

米の品質に関わる遺伝子の機能解明と品質改変のためのイネ育種素材開発