New insights into the mode of action of thiamethoxam on seed germination physiology

Abstract

In order to contribute to understanding the mode of action of the thiamethoxam in plants, we have carried out a virtual screening and in silico molecular docking study with TIA. The pharmacophoric search for protein ligands with three-dimensional structures similar to TIA resulted in several protein ligands with Tanimoto score equal to or greater tha 0.5, but only the ligand isoniazid (ISZ) was bound to a protein from plant origin, which was an ascorbate peroxidase (APX). Molecular docking of ISZ and TIA to several APX’s revealed that TIA binds more strongly to these enzymes than ISZ, suggesting that TIA acts on plants through inhibition of this enzyme. When seedlings obtained from wheat and soybean seeds treated with different concentrations ot TIA, the activity of APX decreased with increasing TIA concentration. Therefore, both in silico and experimental results suggest that TIA can promotes plant growth through inhibition of the enzyme APX.