Finding the physiological function of the enzyme GPCAT. : a gene expression study using Arabidopsis plants with silenced GPCAT gene

Abstract: The aim of this project was to study the enzyme Glycerophosphocholine Acyltransferase (GPCAT) and try to find its physiological function. The biochemical reaction that the enzyme GPCAT catalyses is known, but its physiological function, e.g. why and when plants need the enzyme GPCAT, is unknown. To investigate the physiological function, Arabidopsis plants with (wild type) and without (knockout 19) the gene encoding for the enzyme GPCAT were cultivated and then exposed to abiotic stresses. The gene expression of six genes were studied by Q-RT-PCR and differences in gene expression was calculated by the Pfaffl method. The three genes that were associated with Sphingolipids (delta-9 acyl-lipid desaturase 2, very-long-chain 3-oxoacyl-CoA synthase and sphinganine C4-monooxygenase 1) showed higher gene expression in the knockout 19 plants than the wild type in the cold treatments. This implies that the silencing of GPCAT gene influences the genes in sphingolipids synthesis in the cold treated plants. Therefore, GPCAT might be involved in the regulation of lipids, with focus on sphingolipids, in cold stress.