Arabidopsis trigalactosyldiacylglycerol1 mutants reveal a critical role for phosphtidylcholine remodeling in lipid homeostasis
- PMID: 39276345
- DOI: 10.1111/tpj.17020
Arabidopsis trigalactosyldiacylglycerol1 mutants reveal a critical role for phosphtidylcholine remodeling in lipid homeostasis
Abstract
Lipid remodeling plays a critical role in plant response to abiotic stress and metabolic perturbations. Key steps in this process involve modifications of phosphatidylcholine (PC) acyl chains mediated by lysophosphatidylcholine: acyl-CoA acyltransferases (LPCATs) and phosphatidylcholine: diacylglycerol cholinephosphotransferase (ROD1). To assess their importance in lipid homeostasis, we took advantage of the trigalactosyldiacylglycerol1 (tgd1) mutant that exhibits marked increases in fatty acid synthesis and fatty acid flux through PC due to a block in inter-organelle lipid trafficking. Here, we showed that the increased fatty acid synthesis in tgd1 is due to posttranslational activation of the plastidic acetyl-coenzyme A carboxylase. Genetic analysis showed that knockout of LPCAT1 and 2 resulted in a lethal phenotype in tgd1. In addition, plants homozygous for lpcat2 and heterozygous for lpcat1 in the tgd1 background showed reduced levels of PC and triacylglycerols (TAG) and alterations in their fatty acid profiles. We further showed that disruption of ROD1 in tgd1 resulted in changes in fatty acid composition of PC and TAG, decreased leaf TAG content and reduced seedling growth. Together, our results reveal a critical role of LPCATs and ROD1 in maintaining cellular lipid homeostasis under conditions, in which fatty acid production largely exceeds the cellular demand for membrane lipid synthesis.
Keywords: Arabidopsis thaliana; trigalactosyldiacylglycerol1; fatty acid synthesis; lipid remodeling; lipid trafficking; phosphatidylcholine.
© 2024 Society for Experimental Biology and John Wiley & Sons Ltd.
References
REFERENCES
-
- Andre, C., Haslam, R.P. & Shanklin, J. (2012) Feedback regulation of plastidic acetyl‐CoA carboxylase by 18:1‐acyl carrier protein in Brassica napus. Proceedings of the National Academy of Sciences of the United States of America, 109, 10107–10112.
-
- Bates, P.D., Durrett, T.P., Ohlrogge, J.B. & Pollard, M. (2009) Analysis of acyl fluxes through multiple pathways of triacylglycerol synthesis in developing soybean embryos. Plant Physiology, 150, 55–72.
-
- Bates, P.D., Fatihi, A., Snapp, A.R., Carlsson, A.S., Browse, J. & Lu, C.F. (2012) Acyl editing and headgroup exchange are the major mechanisms that direct polyunsaturated fatty acid flux into triacylglycerols. Plant Physiology, 160, 1530–1539.
-
- Bates, P.D., Ohlrogge, J.B. & Pollard, M. (2007) Incorporation of newly synthesized fatty acids into cytosolic glycerolipids in pea leaves occurs via acyl editing. Journal of Biological Chemistry, 282, 31206–31216.
-
- Bates, P.D., Stymne, S. & Ohlrogge, J. (2013) Biochemical pathways in seed oil synthesis. Current Opinion in Plant Biology, 16, 358–364.
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