College of Horticulture and Plant Protection, Henan University of Science and Technology, Luoyang 471023, PR China.
College of Horticulture and Plant Protection, Henan University of Science and Technology, Luoyang 471023, PR China; Henan International Joint Laboratory of Stress Resistance Regulation and Safe Production of Protected Vegetables, Luoyang 471023, PR China; Henan Engineering Technology Research Center for Horticultural Crop safety and Disease Control, Luoyang 471023, PR China.
J Hazard Mater. 2023 Feb 5;443(Pt A):130212. doi: 10.1016/j.jhazmat.2022.130212. Epub 2022 Oct 19.
Pesticide overuse has led to serious global concerns regarding food safety and environmental pollution. Although the reduction of pesticide residue is critical, our knowledge about induced pesticide metabolism in plants remains fragmentary. Melatonin (N-acetyl-5-methoxytryptamine) is an effective stress-relieving agent in both animals and plants, but little is known about the melatonin signaling mechanism and its effect on pesticide metabolism in plants. Here, we found that exogenous melatonin treatment significantly reduced chlorothalonil residue by 41 % but suppression of endogenous melatonin accumulation increased chlorothalonil residue in tomato leaves. Moreover, melatonin increased photosynthesis, Fv/Fm, Calvin cycle enzyme activity, antioxidant enzyme activity, glutathione pool, and RESPIRATORY BURST HOMOLOG1 (RBOH1) expression in tomato leaves. However, the upregulation of RBOH1, CYP724B2, GST1, GST2, GSH and ABC, the increased glutathione concentrations and the activity of detoxification enzymes due to melatonin treatment were all significantly attenuated by the treatment with an NADPH oxidase inhibitor and a ROS scavenger, indicating a clear relationship between the reduction of pesticide residue and induction in detoxifying enzymes and genes upon melatonin treatment in an apoplastic HO-dependent manner. These results reveal that melatonin-induced reduction in chlorothalonil residue is mediated by HO signaling in tomato leaves.
过度使用农药导致了人们对食品安全和环境污染的严重关注。尽管减少农药残留至关重要，但我们对植物中诱导的农药代谢的了解仍然很零碎。褪黑素（N-乙酰-5-甲氧基色胺）是动物和植物中一种有效的缓解应激的物质，但关于褪黑素信号机制及其对植物中农药代谢的影响知之甚少。在这里，我们发现外源褪黑素处理可使百菌清残留显著减少 41%，但抑制内源性褪黑素积累会增加番茄叶片中的百菌清残留。此外，褪黑素可增加番茄叶片中的光合作用、Fv/Fm、卡尔文循环酶活性、抗氧化酶活性、谷胱甘肽池和 RESPIRATORY BURST HOMOLOG1（RBOH1）表达。然而，NADPH 氧化酶抑制剂和 ROS 清除剂处理可显著减弱褪黑素处理引起的 RBOH1、CYP724B2、GST1、GST2、GSH 和 ABC 的上调、谷胱甘肽浓度的增加以及解毒酶活性的增加，表明在质外体 HO 依赖性方式下，褪黑素处理诱导解毒酶和基因表达，从而减少农药残留。这些结果表明，褪黑素诱导的百菌清残留减少是由番茄叶片中的 HO 信号介导的。
