Production of very long chain polyunsaturated omega-3 and omega-6 fatty acids in plants.

We report the production of two very long chain polyunsaturated fatty acids, arachidonic acid (AA) and eicosapentaenoic acid (EPA), in substantial quantities in a higher plant. This was achieved using genes encoding enzymes participating in the omega3/6 Delta8 -desaturation biosynthetic pathways for the formation of C20 polyunsaturated fatty acids. Arabidopsis thaliana was transformed sequentially with genes encoding a Delta9 -specific elongating activity from Isochrysis galbana, a Delta8 -desaturase from Euglena gracilis and a Delta5 -desaturase from Mortierella alpina.