Expression of Δ~6-Fatty Acid Desaturase Gene from Mortierella alpina in γ-Linolenic Acid Production in Soybean

γ-linolenic acid (GLA, C18:3 Δ6.9.12) is an essential fatty acid in human diet. Δ6-fatty acid desaturase(D6D) is the rate-limiting enzyme in production of GLA. It can convert from linoleic acid(LA, C18:2 Δ9.12) to GLA. The Δ6-fatty acid desaturase gene from Mortitieralla alpina was transferred into cultivars Jilin35, Jilin43, Jilin47, Suinong10, Suinong14 and Heinong37 soybean successfully with Agrobacterium mediated cotylendon node transformation system. PCR and Southern hybridization analysis on the transgenic plants has proved that exogenous gene has been transferred and integrated into soybean genome. The Northern hybridization analysis showed that the D6D gene of transgenic soybean was expressed at mRNA level. Total fatty acids extracted from the positive transgenic soybean were analyzed by gas chromatography (GC) of methyl esters to confirm the transgenic soybean containing a functional Δ6-fatty acid desaturase gene. Among the seeds tested, the highest content of GLA amounts to 25.165% of the total fatty acids. The presence of GLA indicates that the Δ6-fatty acid desaturase gene from Mortitieralla alpina were expressed in transgenic soybean.