Enantioselective Response of Wheat Seedlings to Imazethapyr: From the Perspective of Fe and the Secondary Metabolite DIMBOA.

The responses of trace elements and secondary metabolites to stress can reflect plant adaptation to the environment. If and how the imperative trace element Fe and the defensive secondary metabolite 2,4-dihydroxy-7-methoxy-2-1,4-benzoxazine-3(4)-one (DIMBOA) mediate the toxicity of chiral herbicides to nontarget plants remains inconclusive. We found that the herbicidal-active imazethapyr enantiomer [()-IM] stimulated heme oxygenase-1 activity, triggered the release of the catalytic product Fe, increased reactive oxygen species production, decreased the DIMBOA content, and increased the DIMBOA-Fe content.

Enantioselective effects of imazethapyr on the secondary metabolites and nutritional value of wheat seedlings.

The secondary metabolism of plants is key for mediating responses to environmental stress, but few studies have examined how the relationship between secondary metabolism and the stress response of plants is affected by exposure to chiral herbicides. Here, we studied the enantioselective disturbance of the chiral herbicide imazethapyr (IM) on the secondary metabolism and nutrient levels of wheat seedlings. The bioactive enantiomer R-IM significantly increased the contents of major secondary metabolites, including phenolic acids, flavonoids, and carotenoids but greatly inhibited the production of benzoxazine.