Signaling network of phototropin-mediated stomatal opening

2021 Fiscal Year Final Research Report

• Project/Area Number: 18H02468
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Review Section: Basic Section 44030:Plant molecular biology and physiology-related
• Research Institution: Yamaguchi University
• Principal Investigator: Takemiya Atsushi 山口大学, 大学院創成科学研究科, 准教授 (80448406)
• Project Period (FY): 2018-04-01 – 2021-03-31
• Keywords: フォトトロピン / 気孔 / 青色光 / シグナル伝達 / タンパク質リン酸化

Outline of Final Research Achievements

Stomata open in response to light, facilitating the uptake of CO2 for photosynthetic carbon fixation. Phototropins, plant-specific blue light photoreceptor kinases, phosphorylate their substrate BLUS1 kinase, leading to activation of the plasma membrane H+-ATPase and stomatal opening. In this study, we revealed the detailed regulatory mechanisms of BLUS1 kinase activity and showed that the decrease of intercellular CO2 concentration by photosynthesis in addition to the BLUS1-mediated H+-ATPase activation is necessary for light-dependent stomatal opening. Furthermore, we showed that phototropins mediate stomatal closure as well as stomatal opening in response to blue light, thereby strictly controlling stomatal aperture. We also found that autophagy sustains light-dependent stomatal opening through regulating ROS homeostasis in guard cells.

Free Research Field

植物生理学

Academic Significance and Societal Importance of the Research Achievements

本研究ではこれまで未解明であった光シグナルと光合成による相乗的な気孔開口のメカニズムに加え、フォトトロピンによる気孔閉鎖やオートファジーによる気孔開口制御など、これまで想像されていなかった気孔開閉制御機構の存在を初めて示した。今回見出された新たな気孔開閉制御のメカニズムを分子レベルで解明することで、高い生産性や環境適応能力を備えた農作物の開発に繋がり、将来的に地球規模での環境・食料・エネルギー問題の解決に貢献することが期待される。