Fatty acid synthesis in developing leaves of Brassica napus in relation toleaf growth and changes is activity of 3-oxoacyl-ACP reductase

In young expanding leaves of Brassica napus, the demand for fatty acids is met by de novo biosynthesis of fatty acid synthase components, as demonstra ted by 3-oxoacyl-ACP reductase, Using a novel radio-chemical assay for 3-ox oacyl-ACP reductase and specific antibodies, we have demonstrated a direct relationship between the increase in activity and synthesis of polypeptide. The maximum rate of fatty acid synthesis was between 4 and 7 days post-eme rgence, but slowed after this point even though 3-oxoacyl-ACP reductase act ivity mas high. Leaf area continued to expand in a linear fashion after red uctions in both enzyme activity and the rate of fatty acid synthesis. (C) 2 001 Federation of European Biochemical Societies. Published by Elsevier Sci ence B.V. All rights reserved.