INHIBITION OF FATTY-ACID ELONGATION PROVIDES A BASIS FOR THE ACTION OF THE HERBICIDE, ETHOFUMESATE, ON SURFACE WAX FORMATION

We have studied the effects of ethofumesate on fatty acid synthesis in germinating pea seeds and developing barley leaves. Ethofumesate inhibited labelling of fatty acids from C-14-acetate, this inhibition being much greater for very long chain fatty acids than those of shorter chain length made de novo. Measurement of elongation reactions, using pea seed microsomal fractions and [2-C-14]malonyl-CoA, confirmed that ethofumesate had a preferential action on fatty acid elongases. The data provide a possible explanation for the action of ethofumesate on epicuticular wax formation.