The physiological significance of lipid metabolic fluxes in guard cells

2022 Fiscal Year Final Research Report

• Project/Area Number: 18K06293
• 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: Kyushu University
• Principal Investigator: Negi Juntaro 九州大学, 理学研究院, 准教授 (70529099)
• Project Period (FY): 2018-04-01 – 2023-03-31
• Keywords: 脂質代謝 / 気孔 / 小胞体経路 / プラスチド経路 / 葉緑体

Outline of Final Research Achievements

In plants, plastidial glycolipids are synthesized via two distinct pathways: the plastidic pathway and the endoplasmic reticulum (ER) pathway. The relative contributions of the plastidic and the ER pathways to the plastidial glycolipid synthesis differ among various plant tissues, and our previous studies have shown that the ER pathway is more extensively utilized in guard cells than in mesophyll cells for the synthesis of chloroplast glycolipids. On the other hand, the physiological significance of why the ER pathway develops in guard cells is unclear. In this study, we found that galactosyldiacylglycerol (DGDG), one of the chloroplast lipids mainly synthesized by the ER pathway, is essential for stomatal chloroplast formation. We also found that similar to guard cells, root cells exhibit a higher proportion of glycolipid from the ER pathway and that the ER pathway has a significant contribution toward chloroplast development in the root cells.

Free Research Field

植物生理学

Academic Significance and Societal Importance of the Research Achievements

本研究で得られた知見は、葉緑体脂質合成に対する2つの脂質合成経路の寄与度すなわち、葉緑体の脂質代謝バランスが植物組織間で異なることを示しており、組織ごとの脂質代謝バランスの違いが、葉緑体の構造的特徴に影響を及ぼす可能性が示された。植物が２つの脂質代謝経路を持つ意味を理解する上で重要な布石となった。