Biosynthesis of very long chain monounsaturated fatty acids by subcellular fractions of developing seeds

Subcellular fractions from developing seeds of mustard (Sinapis alba), honesty (Lunaria annua) and nasturtium (Tropaeolum majus) synthesize very long chain cis (n?9) monounsaturated fatty acids, e.g. gadoleic (20:1), erucic (22:1) and nervonic (24:1) acid, from oleoyl-CoA and malonyl-CoA by condensation reactions. The particulate 2000 × g and 15 000 × g fractions exhibit considerably higher elongase activities compared to the microsomal or oil body fractions, whereas the soluble (150 000 × g supernatant) fraction is devoid of such activities.