{"title":"质粒和脂滴在叶片衰老和缺氮过程中的中性脂质积累中的各自作用","authors":"Denis Coulon, Houda Nacir, Delphine Bahammou, Juliette Jouhet, Jean-Jacques Bessoule, Laëtitia Fouillen, Claire Bréhélin","doi":"10.1093/jxb/erae301","DOIUrl":null,"url":null,"abstract":"<p><p>Upon abiotic stress or senescence, the size and/or abundance of plastid-localized plastoglobules and cytosolic lipid droplets, both compartments devoted to neutral lipid storage, increase in leaves. Meanwhile, plant lipid metabolism is also perturbed, notably with the degradation of thylakoidal monogalactosyldiacylglycerol (MGDG) and the accumulation of neutral lipids. Although these mechanisms are probably linked, they have never been jointly studied, and the respective roles of plastoglobules and lipid droplets in the plant response to stress are totally unknown. To address this question, we determined and compared the glycerolipid composition of both lipid droplets and plastoglobules, followed their formation in response to nitrogen starvation, and studied the kinetics of lipid metabolism in Arabidopsis leaves. Our results demonstrated that plastoglobules preferentially store phytyl-esters, while triacylglycerols (TAGs) and steryl-esters accumulated within lipid droplets. Thanks to a pulse-chase labeling approach and lipid analyses of the fatty acid desaturase 2 (fad2) mutant, we showed that MGDG-derived C18:3 fatty acids were exported to lipid droplets, while MGDG-derived C16:3 fatty acids were stored within plastoglobules. The export of lipids from plastids to lipid droplets was probably facilitated by the physical contact occurring between both organelles, as demonstrated by our electron tomography study. The accumulation of lipid droplets and neutral lipids was transient, suggesting that stress-induced TAGs were remobilized during the plant recovery phase by a mechanism that remains to be explored.</p>","PeriodicalId":15820,"journal":{"name":"Journal of Experimental Botany","volume":null,"pages":null},"PeriodicalIF":5.6000,"publicationDate":"2024-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Roles of plastoglobules and lipid droplets in leaf neutral lipid accumulation during senescence and nitrogen deprivation.\",\"authors\":\"Denis Coulon, Houda Nacir, Delphine Bahammou, Juliette Jouhet, Jean-Jacques Bessoule, Laëtitia Fouillen, Claire Bréhélin\",\"doi\":\"10.1093/jxb/erae301\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<p><p>Upon abiotic stress or senescence, the size and/or abundance of plastid-localized plastoglobules and cytosolic lipid droplets, both compartments devoted to neutral lipid storage, increase in leaves. Meanwhile, plant lipid metabolism is also perturbed, notably with the degradation of thylakoidal monogalactosyldiacylglycerol (MGDG) and the accumulation of neutral lipids. Although these mechanisms are probably linked, they have never been jointly studied, and the respective roles of plastoglobules and lipid droplets in the plant response to stress are totally unknown. To address this question, we determined and compared the glycerolipid composition of both lipid droplets and plastoglobules, followed their formation in response to nitrogen starvation, and studied the kinetics of lipid metabolism in Arabidopsis leaves. Our results demonstrated that plastoglobules preferentially store phytyl-esters, while triacylglycerols (TAGs) and steryl-esters accumulated within lipid droplets. Thanks to a pulse-chase labeling approach and lipid analyses of the fatty acid desaturase 2 (fad2) mutant, we showed that MGDG-derived C18:3 fatty acids were exported to lipid droplets, while MGDG-derived C16:3 fatty acids were stored within plastoglobules. The export of lipids from plastids to lipid droplets was probably facilitated by the physical contact occurring between both organelles, as demonstrated by our electron tomography study. The accumulation of lipid droplets and neutral lipids was transient, suggesting that stress-induced TAGs were remobilized during the plant recovery phase by a mechanism that remains to be explored.</p>\",\"PeriodicalId\":15820,\"journal\":{\"name\":\"Journal of Experimental Botany\",\"volume\":null,\"pages\":null},\"PeriodicalIF\":5.6000,\"publicationDate\":\"2024-10-30\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Journal of Experimental Botany\",\"FirstCategoryId\":\"99\",\"ListUrlMain\":\"https://doi.org/10.1093/jxb/erae301\",\"RegionNum\":2,\"RegionCategory\":\"生物学\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q1\",\"JCRName\":\"PLANT SCIENCES\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Journal of Experimental Botany","FirstCategoryId":"99","ListUrlMain":"https://doi.org/10.1093/jxb/erae301","RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"PLANT SCIENCES","Score":null,"Total":0}
Roles of plastoglobules and lipid droplets in leaf neutral lipid accumulation during senescence and nitrogen deprivation.
Upon abiotic stress or senescence, the size and/or abundance of plastid-localized plastoglobules and cytosolic lipid droplets, both compartments devoted to neutral lipid storage, increase in leaves. Meanwhile, plant lipid metabolism is also perturbed, notably with the degradation of thylakoidal monogalactosyldiacylglycerol (MGDG) and the accumulation of neutral lipids. Although these mechanisms are probably linked, they have never been jointly studied, and the respective roles of plastoglobules and lipid droplets in the plant response to stress are totally unknown. To address this question, we determined and compared the glycerolipid composition of both lipid droplets and plastoglobules, followed their formation in response to nitrogen starvation, and studied the kinetics of lipid metabolism in Arabidopsis leaves. Our results demonstrated that plastoglobules preferentially store phytyl-esters, while triacylglycerols (TAGs) and steryl-esters accumulated within lipid droplets. Thanks to a pulse-chase labeling approach and lipid analyses of the fatty acid desaturase 2 (fad2) mutant, we showed that MGDG-derived C18:3 fatty acids were exported to lipid droplets, while MGDG-derived C16:3 fatty acids were stored within plastoglobules. The export of lipids from plastids to lipid droplets was probably facilitated by the physical contact occurring between both organelles, as demonstrated by our electron tomography study. The accumulation of lipid droplets and neutral lipids was transient, suggesting that stress-induced TAGs were remobilized during the plant recovery phase by a mechanism that remains to be explored.
期刊介绍:
The Journal of Experimental Botany publishes high-quality primary research and review papers in the plant sciences. These papers cover a range of disciplines from molecular and cellular physiology and biochemistry through whole plant physiology to community physiology.
Full-length primary papers should contribute to our understanding of how plants develop and function, and should provide new insights into biological processes. The journal will not publish purely descriptive papers or papers that report a well-known process in a species in which the process has not been identified previously. Articles should be concise and generally limited to 10 printed pages.