BACKGROUND Triacylglycerols (TAGs) are the main composition of plant seed oil. Long-chain acyl-coenzyme A synthetases (LACSs) catalyze the synthesis of long-chain acyl-coenzyme A, which is one of the primary substrates for TAG synthesis. In Arabidopsis, the LACS gene family contains nine members, among which LACS1 and LACS9 have overlapping functions in TAG biosynthesis. However, functional characterization of LACS proteins in rapeseed have been rarely reported. RESULTS An orthologue of the Arabidopsis LACS2 gene (BnLACS2) that is highly expressed in developing seeds was identified in rapeseed (Brassica napus). The BnLACS2-GFP fusion protein was mainly localized to the endoplasmic reticulum, where TAG biosynthesis occurs. Interestingly, overexpression of the BnLACS2 gene resulted in significantly higher oil contents in transgenic rapeseed plants compared to wild type, while BnLACS2-RNAi transgenic rapeseed plants had decreased oil contents. Furthermore, quantitative real-time PCR expression data revealed that the expression of several genes involved in glycolysis, as well as fatty acid (FA) and lipid biosynthesis, was also affected in transgenic plants. CONCLUSIONS A long chain acyl-CoA synthetase, BnLACS2, located in the endoplasmic reticulum was identified in B. napus. Overexpression of BnLACS2 in yeast and rapeseed could increase oil content, while BnLACS2-RNAi transgenic rapeseed plants exhibited decreased oil content. Furthermore, BnLACS2 transcription increased the expression of genes involved in glycolysis, and FA and lipid synthesis in developing seeds. These results suggested that BnLACS2 is an important factor for seed oil production in B. napus.

中文翻译：

---

长链酰基辅酶A合成酶2参与甘蓝型油菜的种子油生产。

背景技术三酰基甘油（TAG）是植物种子油的主要成分。长链酰基辅酶A合成酶（LACS）催化长链酰基辅酶A的合成，长链酰基辅酶A是TAG合成的主要底物之一。在拟南芥中，LACS基因家族包含9个成员，其中LACS1和LACS9在TAG生物合成中具有重叠功能。但是，鲜有关于油菜籽中LACS蛋白的功能表征的报道。结果在油菜（甘蓝型油菜）中鉴定到在发育中的种子中高度表达的拟南芥属LACS2基因的直系同源物（BnLACS2）。BnLACS2-GFP融合蛋白主要位于内质网，TAG生物合成的地方。有趣的是 与野生型相比，BnLACS2基因的过表达导致转基因油菜植株的油含量显着提高，而BnLACS2-RNAi转基因油菜植株的油含量降低。此外，实时定量PCR表达数据还表明，参与糖酵解的几种基因以及脂肪酸（FA）和脂质生物合成的表达在转基因植物中也受到影响。结论在甘蓝型油菜中鉴定出位于内质网中的长链酰基辅酶A合成酶BnLACS2。BnLACS2在酵母和油菜籽中的过表达可能增加油含量，而BnLACS2-RNAi转基因油菜籽植物的油含量降低。此外，BnLACS2转录增加了正在发育的种子中参与糖酵解，FA和脂质合成的基因的表达。