Jiangsu Key Laboratory of Pesticide Science, College of Sciences , Nanjing Agricultural University , Nanjing 210095 , China.
College of Plant Protection , Henan Agricultural University , Zhengzhou 450002 , China.
Chem Res Toxicol. 2018 Aug 20;31(8):752-761. doi: 10.1021/acs.chemrestox.8b00100. Epub 2018 Jul 17.
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 (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.
茉莉酸（JA）[或甲基金雀花酸（MeJA）]是植物生长、发育和抵御环境胁迫的重要调节剂之一，但 JA 如何参与植物中农药积累和降解的调节在很大程度上是未知的。本研究调查了 MeJA 对小麦（ Triticum aestivum）中异丙隆（IPU）残留解毒和降解的贡献。小麦植株暴露于 4mg/kg 的异丙隆（环境现实浓度）。生长水平和叶绿素浓度降低，而植物的电解质渗透率增强。当植物喷洒 0.1μM MeJA 时，异丙隆诱导的植物毒性显著减轻，表现为叶绿素浓度增加，小麦细胞损伤程度降低。在 MeJA 存在的情况下，几种与异丙隆相关的应激标记酶的活性受到抑制。我们通过高效液相色谱法测量了小麦中异丙隆及其在土壤中的残留量。有 MeJA 存在时，小麦和土壤中异丙隆的浓度急剧降低。使用超高效液相色谱-串联质谱法，鉴定了小麦中 12 种异丙隆衍生物（8 种代谢物和 4 种轭合物）。我们进一步提供了证据表明，在暴露于异丙隆的植物中，内源 MeJA 的浓度显著增加。这些结果表明，当在真实的环境异丙隆污染土壤中生长时，MeJA 能够解毒或降解小麦中的异丙隆。
