Analysis of the Unique Photoprotective Mechanism of Green Algae Mesostigma - From Freshwater Green Algae to Land Plants

2023 Fiscal Year Final Research Report

• Project/Area Number: 21K06224
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 44030:Plant molecular biology and physiology-related
• Research Institution: Hokkaido University
• Principal Investigator: Takabayashi Atsushi 北海道大学, 低温科学研究所, 助教 (90546417)
• Project Period (FY): 2021-04-01 – 2024-03-31
• Keywords: 光合成 / 陸上植物への進化 / 光防御機構

Outline of Final Research Achievements

For plants, land is a harsh environment where they are exposed to environmental stresses such as drought, UV, and intense light. Therefore, it was necessary for plants to acquire photoprotective mechanisms as they evolved from freshwater green algae to land plants. It has been reported that the function and role of PsbS differs between green algae and land plants, but it is unclear at what point this changed. In this study, we introduced the PsbS genes from some streptophytes, the ancestors of land plants, into Arabidopsis thaliana. We found that its PsbS functions similarly to that of land plants. Interestingly, the stability of PsbS from green algae was remarkably low, suggesting that increased stability of PsbS may have been the key to their evolution into land plants.

Free Research Field

植物科学

Academic Significance and Societal Importance of the Research Achievements

植物は光に対する防御機構を持たなければ、強い太陽光を受けると直ちに枯死してしまう。
そのため、水中に生息する緑藻から陸上植物への進化においては光防御機構の獲得が極めて重要なプロセスであった。本研究ではその光防御機構の制御を司るPsbSタンパク質に着目し、陸上植物への進化においてはその安定性の向上が鍵であっただろうことを見出した。