Researcher National Research Council of Canada, Saskatchewan, Canada
Abstract: Docosatrienoic acid (DTA, 22:3n-3) and docosadienoic acid (DTA, 22:3n-3) are two new very long chain polyunsaturated fatty acids (VLCPUFA) that were recently found to possess anti-inflammatory and antitumor properties comparable to docosahexaenoic acid (DHA, 22:6n-3). However, there is no natural source for these VLCPUFAs. To produce them in oilseed crops for nutraceutical use, the first plant ELO type elongase (3-ketoacyl-CoA synthase) was identified from Eranthis hyemalis that was highly effective for the elongation of polyunsaturated fatty acids. Seed-specific expression of the gene in oilseed crop Brassica carinata showed that the transgenic plants produced a high level of DDA and a moderate level of DTA. To increase the production of DTA, two w-3 desaturases from fungus Claviceps purpurea and Pythium irregulare with different regioselectivity along with a cytoplasmic lysophosphatidic acid acyltransferase from E. hyemalis were sequentially exploited to engineer the oilseed crop, which resulted in a high level of the w-3 VLCPUFA produced in transgenic plants. The amount of DTA and DDA in transgenic B. carinata remained stable over generations. Efficient and sustainable production of DTA and DDA in the oilseed crop provides an opportunity for the new VLCPUFAs with health-promoting properties for cosmetic, food and feed applications.
