2022 Fiscal Year Final Research Report

Optimization of light-environment response and adaptation mechanisms of the practical model diatom

Research Project

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Project/Area Number	20H03116
Research Category	Grant-in-Aid for Scientific Research (B)
Allocation Type	Single-year Grants
Section	一般
Review Section	Basic Section 41050:Environmental agriculture-related
Research Institution	Kyoto University
Principal Investigator	Ifuku Kentaro 京都大学, 農学研究科, 教授 (50359783)
Co-Investigator(Kenkyū-buntansha)	菓子野康浩兵庫県立大学, 理学研究科, 准教授 (20221872) 内山郁夫基礎生物学研究所, ゲノム情報研究室, 准教授 (90243089)
Project Period (FY)	2020-04-01 – 2023-03-31
Keywords	海洋性珪藻 / 光化学系 / 集光性色素タンパク質 / 光合成 / ゲノム解析 / タンパク質立体構造 / 遺伝子発現解析 / ゲノム編集
Outline of Final Research Achievements	We obtained genomic, gene expression, and protein 3D structure information of the diatom Chaetoceros gracilis, which have academic and industrial value, and aimed to optimize their photosynthetic potential by genome editing. We found that the total number of light-harvesting pigment protein genes in C. gracilis is 46 genes and that they are classified into 6 groups. The subunits in the structures of the photosystem-light-harvesting pigment protein complexes of C. gracilis obtained by cryo-electron microscopy were identified. Based on gene expression analysis, the light-harvesting pigment proteins that would be potentially redundant or important for light-environment response were selected and their functions were analyzed by genome editing.
Free Research Field	植物分子生物学・生化学
Academic Significance and Societal Importance of the Research Achievements	日本近海も含めて、海洋に広く分布するツノケイソウChaetoceros属のゲノムを解読し、データベースとして広く一般に公開した。また、紅色系系統の二次共生藻類の光化学系ー集光性色素タンパク質複合体における集光性色素タンパク質の組成と配置を、世界で初めて明らかにした。さらにツノケイソウのゲノム編集を可能とし、遺伝子発現解析の結果に基づいて重要な集光性色素タンパク質を選定し、それらの遺伝子欠損変異体の作成に成功した。野生株と比べて強光条件下での光化学系IIの量子収率が向上する変異株が得られ、珪藻の光捕集能をゲノム編集で操作することで、光エネルギー変換効率の向上が可能であることを示した。