Effect Of Exogenous Methyl Jasmonnate On Detoxification Of Hecbicide Isoproturon In Wheat

Isoproturon(IPU)is a kind of substitute urea herbicide,with a chemical name being 3-(4-isopropyl phenyl)-1,1-two methyl urea.IPU is widely used for prevention and control of weeds in wheat,rice and other crop fields.Wheat is one of the most important economic crops in China and many other parts of the world.Methyl jasmonate(MeJA)is a kind of fatty acid derivatives and widely exists in plants.It is also one of the most important signal molecules in plants,playing muitile roles in growth,development and response to environmental stress.In this study,the MeJA was tested to detoxify wheat exposed to the herbicide isoproturn.We identified the wheat growth in the presence of both isoproturon and MeJA and showed that treatment with IPU alone blocked the growth of wheat,decreased the chlorophyll content in leaves,inhibited the transmission of electrons in photosystem II,which further affects the normal photosynthesis of wheat.Addition of exogenous MeJA at 0.1 mol L-1 significantly reduced the IPU damage of wheat by decreasing the membrane lipid injury of plants and the activities of antioxidant enzymes,biomarkers of oxidative stresses.To study the effect of MeJA on accumulation of IPU in wheat and existing in soil where wheat plants grew,the concentrations in both media were quantified.Application of MeJA to wheat reduced the accumulation of IPU in plants and the residues in soil as well.The effect of MeJA on metabolism of IPU in wheat and the possible metabolic pathways of IPU metabolism or degradation was characterized and analyzed by high resolution liquid chromatography-mass spectrometry(UPLC/Q-TOF-MS2).We found that MeJA could promote the metabolism of IPU in wheat.Analyzing the degradation products of IPU showed that IPU could be metabolized or degraded through hydroxylation,N-dealkylation and glycosylation(sugar conjugation).These results indicate that MeJA is able to facilitate the metabolism and degradation of isoproturon in wheat.