Elucidation of the phototropin-mediated light signaling network

2023 Fiscal Year Final Research Report

• Project/Area Number: 21H02511
• 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): 2021-04-01 – 2024-03-31
• Keywords: 気孔開口 / 青色光 / 光合成 / フォトトロピン / 細胞膜H+-ATPase

Outline of Final Research Achievements

Stomatal pores surrounded by paired guard cells in the epidermis of terrestrial plants open in response to light, facilitating the uptake of carbon dioxide crucial for photosynthesis. The plasma membrane H+-ATPase acts as a primary transporter that expels H+ from guard cells, creating a driving force for stomatal opening. However, the mechanism of light activation of H+-ATPase is not yet fully understood. In this study, we found that two Thr residues within the C-terminal autoinhibitory domain of H+-ATPase are phosphorylated in response to blue light. These phosphorylations are essential for activating H+-ATPase and stomatal opening. Furthermore, we showed that the upstream Thr residue is also phosphorylated by photosynthesis in guard cells, further facilitating stomatal opening. This study provides mechanistic insights into H+-ATPase activation 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細胞膜H+-ATPaseの光活性化の仕組みを明らかにし、気孔開口の駆動力形成機構の理解に大きな前進をもたらした。H+-ATPaseは植物の生存に必須な一次輸送体であり、孔辺細胞以外の組織・細胞にも発現している。本研究で見出した仕組みを応用しH+-ATPaseの活性を人為的に制御することで、植物の成長や光合成を促進する基盤技術の開発に繋がることが期待される。