Fluazifop, a grass-selective herbicide which inhibits acetyl-CoA carboxylase in sensitive plant species

Abstract

Fluazifop is a grass-selective herbicide that appears to act by inhibiting fatty acid synthesis de novo in sensitive species. Results from four different types of experiment show that this inhibition is due to an action of fluazifop on acetyl-CoA carboxylase and not on fatty acid synthetase. The acetyl-CoA carboxylase from sensitive barley (Hordeum vulgare), but not from resistant pea (Pisum sativum), is inhibited by the R stereoisomer, a finding that agrees with the herbicidal specificity of fluazifop.

The effect of diflufenican on lipid metabolism in plants

“…These findings confirmed the h viva labelling experiments and thus pointed to fatty acid synthetase (FAS) as a target for diflufenican. This proposal was confirmed by assaying fatty acid synthetase [4] directly in soluble fractions from germinating pea and avocado mesocarp.…”

Acetyl‐CoA carboxylase: a rapid novel assay procedure used in conjunction with the preparation of enzyme from maize leaves

“…Thus, the aryloxyphenoxypropionic acids [l-5] are inhibitory to the monocot leaf enzyme with considerably less activity against the dicot enzyme. It is known that onIy the R-enantiomer inhibits the enzyme [4,5], and kinetic analyses have shown non-competitive inhibition with respect to all three substrates, acetyl-CoA, MgATP and bicarbonate by one of the herbicides (diclofop) in this series [4].…”

“…This is the active acid component of the grass-specific herbicide fluazifop-butyl (marketed under the trade name 'Fusilade') that has been shown to inhibit acetyl-CoA carboxylase in barley, but not in peas [5]: Results of inhibition experiments are given in terms of ICss. This is defined as the concentration of inhibitor required to give 50% inhibition.…”

Prediction of embryotoxic potential using the ReProGlo stem cell-based Wnt reporter assay

“…A valproic acid derivative, (+-)-2-ethyl-4-methyl pentanoic acid, positive in the DART prediction, has been reported to lack teratogenic potential in vivo [30]. Fluazifop-p-butyl is a herbicide which inhibits acetyl-CoA carboxylase of plants [31]. It is rapidly hydrolyzed by esterases in plants, dogs, rats and humans [32,33] to fluazifop, which may be the active compound.…”