Molecular Binding of Cycloxydim to Acetyl-CoA Carboxylase in Cultivated Soybeans and Weed Plants

Acetyl-CoA carboxylase (ACC) is one of the main enzymes that play a regulatory role in the biosynthesis of fatty acids in plants. Cyclodime is one of the herbicides that is an inhibitor of this enzyme. Some weedy cereal plants, such as common hedgehog (Echinochloa crus-galli L.) and annual bluegrass (Poa annua L.), are resistant to cycloxyme. Other types of grass weeds – blood-red dewdrop (Digitaria sanguinalis (L.) Scop.) and green bristle (Setaria viridis (L.) P. Beauv.), on the contrary, are susceptible to the herbicide. The molecular mechanisms underlying ACC resistance are poorly understood. The explanation of the mechanism of resistance probably lies in the structure of ACC in different species. The use of bioinformatics methods will help to understand the mechanisms of adaptation based on the molecular properties of the enzyme, which will contribute to the creation of new herbicides. The purpose of this work was to study the specifics of the binding of cycloxydime to the ACC enzyme for each of these weed species, including soy (Glycine max (L.) Merr.). For weeds E. crus-galli and P. annua revealed from 6 to 7 possible complexes with different ligand positions relative to the receptor, which could potentially explain the mechanism of resistance. At the same time, a low binding energy was determined for the cycloxydime complex with G. max (up to –7.31 kcal/mol), which demonstrates the presence of other resistance mechanisms in the culture.