A molecular genetic approach to reducing the saturated fatty acid content of canola oil

Brassica napus is known to contain an endogenous and soluble stearoyl-acyl carrier protein (Δ918:0-ACP) desaturase, but does not express a palmitic (16:0)-ACP desaturase. Levels of 16:0 are low in canola oil and are associated with enhanced cholesterol biosynthesis in humans. In an attempt to further reduce the saturated fatty acid (SFA) content of canola oil, B. napus L. cv Westar was transformed with a cDNA encoding a Δ916:0-ACP desaturase from cat's claw (Doxantha unguis-cati L.). Arabidopsis thaliana was also transformed with this cDNA. Transformation of both oilseeds resulted in increased production of palmitoleic acid (Δ916:1) and many other effects on fatty acid composition. Overall, the SFA content did not decrease in either oilseed and investigation to why this effect occurred was examined using transgenic B. napus. Molecular genetic testing on second generation B. napus also determined the plants contained the cDNA of interest and were transcribing the cDNA.