Characterization of Wheat (Triticum aestivum) Response to Mesotrione, a Triketone Herbicide

Abstract

Mesotrione is used for weed control in corn and sorghum (pre-emergence) but not in wheat. Corn metabolizes mesotrione via the activity of cytochrome P450 (P450) enzymes. To understand the response of wheat genotypes to mesotrione application, a collection of wheat germplasm including winter, spring genotypes, and mutant lines was used in this research. In response to a 6× (1× = 105 g ai ha −1 ) dose of mesotrione, two winter wheat genotypes (WW-1 and WW-2) were found to be least sensitive compared to the most sensitive genotype (WW-24), mutant lines (J38 and J327), and spring wheat. Further, application of a P450-inhibitor (malathion) before mesotrione treatment enhanced the sensitivity of WW-1 and WW-2 to mesotrione, suggesting a possible role of P450 enzymes in the detoxification of mesotrione. WW1 and WW2 were found to tolerate higher doses of mesotrione and could be potential donors for the transfer of the mesotrione-resistant trait into elite wheat genotypes.