As a widely used herbicide, atrazine and its two main metabolites of deethylatrazine (DEA) and deisopropylatrazine (DIA) pose an exposure risk for both human beings and animals in the environment. In this study, Caenorhabditis elegans was selected as an in vivo model to compare the toxicity between atrazine and its main metabolites. Upon exposure from the larval stage L1 to adult day 3, both DEA and DIA showed less toxicity on locomotion and reproduction compared with atrazine at concentration of 0.001, 0.01 0.1 and 1 mg/L for parental generation. In addition, exposure to DEA and DIA at concentration of 0.1 mg/L also induced less transgenerational toxicity on locomotion than exposure to atrazine for both parental generation and offspring of F1–F4. Accordingly, exposure to DEA and DIA caused less ROS production and alteration in the expression of some genes (mev-1, gas-1, and clk-1) governing oxidative stress compared to atrazine. Meanwhile, DEA and DIA lead to less increase in expression of superoxide dismutase genes (sod-2 and sod-3) and SOD-3::GFP than atrazine. Moreover, atrazine and its two main metabolites differentially activated the daf-16 encoding FOXO transcriptional factor in insulin signaling pathway during the control of downstream target of SOD-3. Overall, our results highlighted the important role of oxidative stress and anti-oxidation related molecular signals in mediating toxicity of atrazine, DEA and DIA, which provided a novel explanation for the different toxicity between atrazine and its main metabolites.

作为一种广泛使用的除草剂，莠去津及其两种主要代谢物去乙基莠去津（DEA）和去异丙基莠去津（DIA）对环境中的人类和动物都存在暴露风险。本研究选择秀丽隐杆线虫作为体内模型，比较莠去津及其主要代谢物的毒性。从幼虫阶段 L1 到成虫第 3 天，与亲代浓度为 0.001、0.01、0.1 和 1 mg/L 的莠去津相比，DEA 和 DIA 对运动和繁殖的毒性均较低。此外，对于 F1-F4 的亲代和后代，暴露于 0.1 mg/L 浓度的 DEA 和 DIA 也比暴露于莠去津所引起的运动跨代毒性更小。因此，与莠去津相比，暴露于 DEA 和 DIA 会导致较少的 ROS 产生以及一些控制氧化应激的基因（ mev-1、gas-1和clk-1 ）表达的改变。同时，与莠去津相比，DEA和DIA导致超氧化物歧化酶基因（ sod-2和sod-3）和SOD-3::GFP表达的增加较少。此外，莠去津及其两种主要代谢物在SOD-3下游靶标的控制过程中，差异性地激活了胰岛素信号通路中编码FOXO转录因子的daf-16 。总的来说，我们的结果强调了氧化应激和抗氧化相关分子信号在介导莠去津、DEA和DIA毒性中的重要作用，这为莠去津及其主要代谢物之间的不同毒性提供了新的解释。