Molecular cloning and characterization of grains quality stabilization for enhancement of environmental adaptability

2023 Fiscal Year Final Research Report

• Project/Area Number: 21K05868
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 41050:Environmental agriculture-related
• Research Institution: Yamagata University
• Principal Investigator: Hoshino Tomoki 山形大学, 農学部, 教授 (20530174)
• Project Period (FY): 2021-04-01 – 2024-03-31
• Keywords: 穂発芽 / QTL / イネ / 責任遺伝子 / ファインマッピング

Outline of Final Research Achievements

In this study, to elucidate the gene responsible for Sdr6b, we attempted to isolate mutants of GeneA, a candidate gene of Sdr6b, from the Koshihikari mutant population and prove it by reverse genetics. In four independent mutant lines, the mutant GIs were significantly lower than the wild-type. Results of the exogenous glucose delayed germination test showed that the GI% of NIL was significantly lower than Koshihikari in the 2% glucose treatment. Furthermore, the expression of ABA8ox1 of NIL in embryos was significantly reduced compared to Koshihikari after 3 hours of glucose treatment. These results suggest that GeneA is the responsible gene for Sdr6b and that GeneA induces pre-harvest sprouting resistance by decreasing ABA8ox1 expression and increasing ABA content.

Free Research Field

作物育種学

Academic Significance and Societal Importance of the Research Achievements

本研究において、Sdr6bはABA代謝の上流でこれまでに穂発芽耐性に関してほとんど報告のないグルコース応答に関与し、ABAシグナル伝達を強化させることで穂発芽耐性に導くことが示唆された。今後は、本研究で明らかにされたSdr6bを利用して、昨今の異常気象にも耐え得る、品質安定化品種の育成が期待される。一方、本研究で用いたオワリハタモチは発芽を促進させる遺伝子も含めて候補領域には複数の責任遺伝子が存在すると考えられた。今後は逆遺伝学的手法を用いて責任遺伝子群を包括的に理解することで、穂発芽耐性の分子メカニズムの理解が深めると同時に、これら遺伝子群を用いた育種利用が期待される。