Arabidopsis trigalactosyldiacylglycerol1 mutants reveal a critical role for phosphtidylcholine remodeling in lipid homeostasis.

Autor: Fan J; Biology Department, Brookhaven National Laboratory, Upton, New York, 11973, USA., Sah SK; Biology Department, Brookhaven National Laboratory, Upton, New York, 11973, USA., Lemes Jorge G; Department of Biochemistry, Christopher S. Bond Life Sciences Center, University of Missouri-Columbia, 1201 E Rollins, Columbia, Missouri, 65211, USA., Blanford J; Biology Department, Brookhaven National Laboratory, Upton, New York, 11973, USA., Xie D; Biology Department, Brookhaven National Laboratory, Upton, New York, 11973, USA., Yu L; Biology Department, Brookhaven National Laboratory, Upton, New York, 11973, USA., Thelen J; Department of Biochemistry, Christopher S. Bond Life Sciences Center, University of Missouri-Columbia, 1201 E Rollins, Columbia, Missouri, 65211, USA., Shanklin J; Biology Department, Brookhaven National Laboratory, Upton, New York, 11973, USA., Xu C; Biology Department, Brookhaven National Laboratory, Upton, New York, 11973, USA.
Jazyk: angličtina
Zdroj: The Plant journal : for cell and molecular biology [Plant J] 2024 Oct; Vol. 120 (2), pp. 788-798. Date of Electronic Publication: 2024 Sep 14.
DOI: 10.1111/tpj.17020
Abstrakt: 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.
(© 2024 Society for Experimental Biology and John Wiley & Sons Ltd.)
Databáze: MEDLINE
Externí odkaz: