Physiological role of chloroplast DNA degradation during leaf senescence

2023 Fiscal Year Final Research Report

• Project/Area Number: 21K06230
• 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: Okayama University
• Principal Investigator: Takami Tsuneaki 岡山大学, 総合技術部, 技術専門職員 (70614254)
• Project Period (FY): 2021-04-01 – 2024-03-31
• Keywords: オルガネラDNA / 葉緑体 / 光合成 / 老化

Outline of Final Research Achievements

Chloroplasts contain own DNA, and the amount of chloroplast DNA (cpDNA) is regulated in a tissue-specific manner and during leaf snescence. However, the physiological role of cpDNA degradation remains unclear. In addition, organelle exonuclease, DPD1, is widely conserved in seed plants, and it’s function may be diversified. In this study, we conducted several experiments using model plants Arabidopsis thaliana (dicot) and rice (monocot) for investigating the physiological role of cpDNA degradation. Our results suggested that organelle DNA degradation affects process of leaf senescence through regulating gene expression. Based on our results, the contribution of organelle DNA degradation for plant fitness is varied in plant species.

Free Research Field

植物生理学

Academic Significance and Societal Importance of the Research Achievements

オルガネラDNA研究は酵母や藻類を用いて主に複製、安定性、修復などに関する知見が報告されているが、分解に焦点を当てた研究は少ない。このような研究動向の中で、本研究によってオルガネラDNA分解と植物の老化との関係性が明らかとなった。また単子葉類のイネを用いて研究を行った結果、オルガネラDNA分解酵素DPD1は広く種子植物に保存されているが、その寄与度は植物種により異なっていることが明らかとなった。これらの成果を基盤とすることで作物の育種・品種改良への応用が期待される。