Jasmonic Acids Facilitate the Degradation and Detoxification of Herbicide Isoproturon Residues in Wheat Crops ( Triticum aestivum).

ABSTRACT

Jasmonic acid (JA) [or methyl-jasmonic acid (MeJA)] is one of the important regulators of plant growth, development, and defense with respect to environmental stresses, but how JA is involved in mediation of pesticide accumulation and degradation in plants is largely unknown. This study investigated the contribution of MeJA to detoxification and degradation of isoproturon (IPU) residues in wheat ( Triticum aestivum). Wheat plants were exposed to 4 mg of isoproturon kg-1 (environmentally realistic concentration). The level of growth and chlorophyll concentration were reduced, while the electrolyte permeability in plants was enhanced. When plants were sprayed with 0.1 µM MeJA, the phytotoxicity induced by isoproturon was significantly assuaged, which was manifested by an increased chlorophyll concentration and a reduced level of cellular damage in wheat. Activities of several stress marker enzymes with isoproturon were repressed in the presence of MeJA. We measured accumulation of isoproturon in wheat and its residues in soil by high-performance liquid chromatography. The concentration of isoproturon in wheat and soils with MeJA was drastically reduced. Using ultraperformance liquid chromatography-tandem mass spectrometry, 12 isoproturon derivatives (eight metabolites and four conjugates) in wheat were characterized. We further provided evidence that the concentration of endogenous MeJA was significantly increased in IPU-exposed plants. These results suggest that MeJA was able to detoxify or degrade isoproturon in wheat when grown in a realistic environmental isoproturon-polluted soil.