School of Biological Science, University of Hong Kong, Pokfulam, Hong Kong.
School of Biosciences, Cardiff University, Cardiff, CF10 3AX, UK.
Sci Rep. 2022 Mar 1;12(1):3352. doi: 10.1038/s41598-022-07387-x.
Oilseed rape (Brassica napus) is an important crop that is cultivated for the oil (mainly triacylglycerol; TAG) it produces in its seeds. TAG synthesis is controlled mainly by key enzymes in the Kennedy pathway, such as glycerol 3-phosphate acyltransferase (GPAT), lysophosphatidate acyltransferase (LPAT) and diacylglycerol acyltransferase (DGAT) but can also be produced from phosphoglycerides such as phosphatidylcholine (PC) by the activity of the enzyme phospholipid: diacylglycerol acyltransferase (PDAT). To evaluate the potential for these enzymes to alter oil yields or composition, we analysed transgenic B. napus lines which overexpressed GPAT, LPAT or PDAT using heterologous transgenes from Arabidopsis and Nasturtium and examined lipid profiles and changes in gene expression in these lines compared to WT. Distinct changes in PC and TAG abundance and spatial distribution in embryonic tissues were observed in some of the transgenic lines, together with altered expression of genes involved generally in acyl-lipid metabolism. Overall our results show that up-regulation of these key enzymes differentially affects lipid composition and distribution as well as lipid-associated gene expression, providing important information which could be used to improve crop properties by metabolic engineering.
油菜（甘蓝型油菜）是一种重要的作物，因其种子中产生的油（主要是三酰基甘油；TAG）而被种植。TAG 的合成主要由 Kennedy 途径中的关键酶控制，如甘油 3-磷酸酰基转移酶（GPAT）、溶血磷脂酸酰基转移酶（LPAT）和二酰基甘油酰基转移酶（DGAT），但也可以通过酶磷脂：二酰基甘油酰基转移酶（PDAT）的活性从磷酸甘油酯如磷脂酰胆碱（PC）中产生。为了评估这些酶改变油产量或组成的潜力，我们使用拟南芥和豆瓣菜的异源转基因分析了过表达 GPAT、LPAT 或 PDAT 的转基因油菜品系，并比较了这些品系与 WT 的脂质谱和基因表达变化。在一些转基因系中观察到胚胎组织中 PC 和 TAG 丰度和空间分布的明显变化，以及与酰基脂代谢相关的基因表达的改变。总的来说，我们的结果表明，这些关键酶的上调差异地影响脂质组成和分布以及与脂质相关的基因表达，为通过代谢工程改善作物特性提供了重要信息。
