Eco-physiological mechanism of the intraspecific variation in photoprotective mechanisms

2023 Fiscal Year Final Research Report

• Project/Area Number: 17KK0142
• Research Category: Fund for the Promotion of Joint International Research (Fostering Joint International Research)
• Allocation Type: Multi-year Fund
• Research Field: Ecology/Environment
• Research Institution: Osaka Metropolitan University (2022-2023); The University of Tokyo (2020-2021); Tohoku University (2017-2019)
• Principal Investigator: Oguchi Riichi 大阪公立大学, 大学院理学研究科, 准教授 (10632250)
• Project Period (FY): 2018 – 2023
• Keywords: 種内変異 / 生態学 / 温度依存性 / 適応

Outline of Final Research Achievements

Excessive light causes photoinhibition of photosynthetic machinery, which decreases photosynthetic- and growth-rate. Various protective mechanisms against photoinhibition have been already reported. The evolution of these various mechanisms would indicate the strong selection pressure by photoinhibition, but we have scarce information about the effect of photoinhibition on diversification and distribution of plants. In the present research, intra-specific variation in temperature dependencies of cyclic electron transport around Photosystem I and state transitions are evaluated. These temperature dependencies differed depending on ecotypes. It is also indicated that temperature dependency of cyclic electron transport around Photosystem I is more strongly affected by the temperature dependency of Photosystem I activity rather than that of Photosystem II activity.

Free Research Field

植物生理生態学

Academic Significance and Societal Importance of the Research Achievements

光阻害回避機構と考えられている光化学系I循環的電子伝達およびステート遷移能力はどちらも低温で強く低下することが知られている。そのため、低温での光阻害の増加の要因となっていると考えられる。本研究で光化学系I循環的電子伝達およびステート遷移能力の温度依存性にエコタイプ間で差が見られたことは、低温での両能力の低下を軽減するメカニズムを持つエコタイプと持たないエコタイプが存在することが示唆されることから、今後そのメカニズムを調べることで、低温での光阻害の増加を緩和する方法の探索につながる可能性が考えられる。