超长链多不饱和脂肪酸VLCPUFAs是预防心脑血管等疾病的生理活性物质，由于其主要的来源-深海鱼类资源快速减少，致使人类饮食中严重缺乏。通过在油料作物中重构VLCPUFAs代谢途径产生这类稀缺脂肪酸被认为是最有效和可行的措施之一，但目前报道的转基因植物中目标产物含量都非常低，研究表明与△6-去饱和酶酰基载体特异性和LPCAT酰基转移酶作用的乙酰CoA与磷脂pool之间的底物流向有关，尚不清楚作用机制。本项拟以酵母和烟草为转基因宿主，通过酰基载体底物特异性的△6-去饱和酶基因与△6-延长酶基因共表达、LPCAT过表达，分析转基因酿酒酵母和烟草叶片中脂肪酸合成的中间产物以及终产物的成分和含量以及酰基CoA库中的组成和含量，阐明△6-去饱和酶酰基载体特异性影响转基因酵母和植物中长链多不饱和脂肪酸(LC-PUFAs)合成的机制；揭示LPCAT影响磷脂酰基载体类型的△6-去饱和酶作用的机制。

Very long-chain polyunsaturated fatty acids (VLPUFAs) are protective against cardiovascular disease and risks associated with metabolic syndrome. The amount of VLPUFAs is extremely low mainly due to the decline in marine fish stocks, which represent the predominant natural reserves of VLPUFAs. One approach which is thought to be effective and feasible may be to express the LCPUFAs-biosynthetic pathway in transgenic plants. However, the content of target product was relatively low according to existing reports. Results showed that the substrate acyl-CoA may exchange with acyl-lipid pool by the reaction of acyl-CoA: lysophosphatidylcholine acyltransferase (LPCAT) and delta 6-desaturase with different substrate specificity. The mechanism of this process is still unclear. In this project, different delta 6-desaturase gene in acyl-carrier type, and delta-6 elongase gene are co-expressed, and lpcat is overexpressed in both yeast and tobacco. Then to analyze the amount of the intermediates, final products and acyl-CoA pool of the transgenic yeast and tobacco. Try to explain how the acyl-CoA specific delta 6-desaturase affects the synthesis of VCLPUFAs in transgenic yeast and plant. Furthermore, we intend to reveal the influence of LPCAT on the transfer efficiency of intermediates generated by phosphate carrier delta 6-desaturase between acyl-CoA pool and Phosphatidylcholine pool.