Li Shasha, Hui Lei, Li Jingchong, Xi Yuan, Xu Jili, Wang Linglong, Yin Lina
State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau, College of Natural Resources and Environment, Northwest A&F University, Yangling, Xianyang 712100, China.
Institute of Soil and Water Conservation, College of Soil and Water Conservation Science and Engineering, Northwest A&F University, Yangling, Xianyang 712100, China.
Plants (Basel). 2024 May 27;13(11):1474. doi: 10.3390/plants13111474.
Salt stress severely reduces photosynthetic efficiency, resulting in adverse effects on crop growth and yield production. Two key thylakoid membrane lipid components, monogalactosyldiacylglycerol (MGDG) and digalactosyldiacylglycerol (DGDG), were perturbed under salt stress. MGDG synthase 1 (MGD1) is one of the key enzymes for the synthesis of these galactolipids. To investigate the function of in response to salt stress, the overexpression (OE) and RNA interference (Ri) rice lines, and a wild type (WT), were used. Compared with WT, the OE lines showed higher chlorophyll content and biomass under salt stress. Besides this, the OE plants showed improved photosynthetic performance, including light absorption, energy transfer, and carbon fixation. Notably, the net photosynthetic rate and effective quantum yield of photosystem II in the OE lines increased by 27.5% and 25.8%, respectively, compared to the WT. Further analysis showed that the overexpression of alleviated the negative effects of salt stress on photosynthetic membranes and oxidative defense by adjusting membrane lipid composition and fatty acid levels. In summary, OsMGD1-mediated membrane lipid remodeling enhanced salt tolerance in rice by maintaining membrane stability and optimizing photosynthetic efficiency.
盐胁迫严重降低光合效率，对作物生长和产量产生不利影响。盐胁迫下，类囊体膜的两种关键脂质成分，单半乳糖基二酰甘油（MGDG）和双半乳糖基二酰甘油（DGDG）受到干扰。MGDG合酶1（MGD1）是这些半乳糖脂合成的关键酶之一。为了研究[此处原文缺失相关基因名称]在响应盐胁迫中的功能，使用了[此处原文缺失相关基因名称]过表达（OE）和RNA干扰（Ri）水稻品系以及野生型（WT）。与WT相比，OE品系在盐胁迫下表现出更高的叶绿素含量和生物量。除此之外，OE植株的光合性能得到改善，包括光吸收、能量传递和碳固定。值得注意的是，与WT相比，OE品系中光系统II的净光合速率和有效量子产率分别提高了27.5%和25.8%。进一步分析表明，[此处原文缺失相关基因名称]的过表达通过调节膜脂组成和脂肪酸水平，减轻了盐胁迫对光合膜和氧化防御的负面影响。总之，OsMGD1介导的膜脂重塑通过维持膜稳定性和优化光合效率增强了水稻的耐盐性。
