Herbicides Disturbing the Synthesis of Very‐long‐chain Fatty Acids

Very-long-chain fatty acids (VLCFAs) are saturated and unsaturated fatty acids longer than 18 carbons (C18) in length; they are important components of various lipids. VLCFAs are synthesized from long-chain fatty acid precursors in the endoplasmic reticulum (ER) by the action of a membrane-bound, multienzyme acyl-CoA elongase complex. The Herbicide Resistance Action Committee (HRAC) has classified herbicides according to the similarity of their induced physiological symptoms according to biochemical findings into different site of action groups. Herbicidal substance classes that are considered to inhibit the biosynthesis of VLCFAs include chloroacetamides, thiophosphates, oxyacetamides, and carbamoyl heterocycles. Isoxazoline herbicides are potent inhibitors of the biosynthesis of VLCFAs and have been classified as members of the K3 herbicides group by the HRAC. Fenoxasulfone is applied as a pre-emergence or early post-emergence herbicide to transplanted rice to control many annual grass weeds, as well as some broadleaf and sedge weeds.