Elucidation of the mechanism of polyamine-induced enhancement of light energy utilization efficiency in plant chloroplasts and cyanobacteria

2022 Fiscal Year Final Research Report

• Project/Area Number: 21K14780
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 38030:Applied biochemistry-related
• Research Institution: Tohoku University
• Principal Investigator: Tsujii Masaru 東北大学, 工学研究科, 助教 (30865887)
• Project Period (FY): 2021-04-01 – 2023-03-31
• Keywords: シアノバクテリア / 葉緑体 / 光合成

Outline of Final Research Achievements

This study aimed to elucidate the photosynthetic control mechanisms in plant chloroplasts and their ancestors, cyanobacteria. pH within and outside the thylakoid membranes is crucial for proper regulation of photosynthetic electron transfer. Polyamines, a class of bioactive substances, possess multiple amine groups and can act as proton buffers depending on the intracellular pH. The applicant successfully purified the polyamine synthesis enzyme, performed activity measurements, and identified the polyamine biosynthetic pathway in cyanobacteria. Furthermore, simultaneous analysis of proton transporters led to the identification of the subcellular localization and transport activity of proton transporters that are crucial for regulating photosynthetic electron transfer.

Free Research Field

シアノバクテリア

Academic Significance and Societal Importance of the Research Achievements

植物や葉緑体の祖先である藍藻は生態系の一次生産者であると同時に、大気中の二酸化炭素を有機物へと変換できる光合成生物である。光合成生物の成長・環境応答機構の解明は現代社会の課題となる大気中の二酸化炭素濃度の上昇や食糧不足を改善するために必須となる。本成果により、藍藻光合成活性に寄与すると考えられるポリアミンの機能同定を行うことに成功した。また、光合成活性に重要なプロトン輸送体を明らかとした。これらの成果は光合成モデル生物となる藍藻の成長・環境応答機構を解明し、食料問題や地球温暖化の改善に繋がる。