Study on gravity response that determines plant architecture.

• Project/Area Number: 17K19388
• Research Category: Grant-in-Aid for Challenging Research (Exploratory)
• Allocation Type: Multi-year Fund
• Research Field: Biology of Cells to Organisms, and related fields
• Research Institution: National Institute for Basic Biology (2019); Nagoya University (2017)
• Principal Investigator: Morita Miyo 基礎生物学研究所, 植物環境応答研究部門, 教授 (10314535)
• Project Period (FY): 2017-06-30 – 2020-03-31
• Project Status: Completed (Fiscal Year 2019)
• Budget Amount: ¥6,500,000 (Direct Cost: ¥5,000,000、Indirect Cost: ¥1,500,000); Fiscal Year 2018: ¥3,250,000 (Direct Cost: ¥2,500,000、Indirect Cost: ¥750,000); Fiscal Year 2017: ¥3,250,000 (Direct Cost: ¥2,500,000、Indirect Cost: ¥750,000)
• Keywords: 重力屈性 / GSA / 傾斜屈性 / 植物生理学 / 植物分子遺伝学

Outline of Final Research Achievements

Lateral roots and lateral shoots generally grow at specific angles with respect to the direction of gravity (GSA; gravitropic setpoint angle). The control of GSA has a great influence on the overall structure of plant body (plant architecture) such as branching and root system, and is thought to be one of the mechanisms for plants to optimize resource acquisition. We had found that the LAZY1-LIKE (LZY) family regulates asymmetric auxin transpot in gravity-sensing cells during gravitropism in Arabidopsis. In addition, we had demonstrated that LZY is involved in GSA regulation of lateral shoots and lateral roots. In this study, we aimed to elucidate the mechanism of GSA control using lzy mutants based on the working hypothesis that GSA is determined by the balance between gravitropism and growth capacity in the opposite direction (AGO: anti-gravitropic offset).

Academic Significance and Societal Importance of the Research Achievements

GSAの制御は、植物の根の張り方や枝振りなど全体の構造（アーキテクチャ）に大きく影響し、植物が地上及び地下部において資源取得を最適化する為の機構の一つと考えられる。これは育種上重要な性質でもあり、詳細な分子機構の解明は将来的に食糧増産などに貢献する可能性がある。また、本研究により主軸の重力屈性と側生器官のGSA制御とを統一的に説明できる分子情報を提供できると期待される。