Trierucoylglycerol biosynthesis in transgenic plants of rapeseed (Brassica napus L)

The erucoyl-CoA specific sn-1-acylglycerol-3-phosphate acyltransferase (LPAAT) of Limnanthes douglasii was functionally expressed in developing seeds of differing high-erucic acid rapeseed genotypes, namely resynthesized lines and cultivars. Lipid analysis revealed that seed oil of transgenic plants in contrast to that of control plants contained trierucoylglycerol as well as a molecular species with two erucoyl groups and one eicosenoyl group. The proportion of trierucoylglycerol was distinctly higher in the seeds from transgenic resynthesized plants than in those from transgenic cultivars. In pooled seed oil fractions, up to 9% trierucoylglycerol (trierucin) was determined and the fatty acid composition at the sn-2 position was found to consist of more than 40% erucic acid. Since the pooled seeds were segregating for the presence of the L. douglasii gene, the analysis of single seeds gave even higher levels of up to 13% trierucin.