College of Chemical Engineering, Huaqiao University, Fujiang 361000, China.
College of Chemical Engineering, Huaqiao University, Fujiang 361000, China.
Ecotoxicol Environ Saf. 2021 Mar 15;211:111894. doi: 10.1016/j.ecoenv.2021.111894. Epub 2021 Jan 17.
Enantiomers of chiral fungicides usually display different toxic effects on nontarget organisms in the surrounding environment, although there are rare reports on the enantioselective toxicity of metconazole (MEZ) to aquatic organisms, such as Microcystis flos-aquae (M. flos-aquae). To explore the enantioselective toxicity of MEZ in algae, the impact of various concentrations (0.001, 0.003, 0.01, 0.03 and 0.1 mg/L) of MEZ on M. flos-aquae over 8 days was investigated. Significant differences were observed between the four enantiomers in chlorophyll a (Chl a) contents, carotenoids, photochemical efficiency (F/F), rapid light-response curves (RLCs), utilization efficiency of light energy (α) and protein contents during treatment time. MEZ can enantioselectively stimulate the chlorophyll fluorescence parameters (RLCs, F/F and α) and carotenoid and Chl a contents of M. flos-aquae, especially at low concentrations (0.001 or 0.003 mg/L). At high concentrations of 0.03 or 0.1 mg/L, the chlorophyll fluorescence parameters (RLCs, F/F and α), protein and Chl a contents of M. flos-aquae exposed to cis-enantiomers were lower than those of M. flos-aquae exposed to trans-enantiomers. These observations indicated that the enantiomers of MEZ pose different toxicities to M. flos-aquae, with the cis-enantiomers more toxic than the trans-enantiomers. These results are beneficial for understanding the enantioselective effects of MEZ enantiomers on nontarget organisms and helpful for evaluating their eco-environment risk.
手性杀菌剂的对映体通常会对周围环境中的非靶标生物表现出不同的毒性作用，尽管关于咪鲜胺（MEZ）对水生生物，如铜绿微囊藻（M. flos-aquae）的对映选择性毒性的报道很少。为了探索 MEZ 在藻类中的对映选择性毒性，研究了不同浓度（0.001、0.003、0.01、0.03 和 0.1 mg/L）的 MEZ 对 M. flos-aquae 8 天的影响。在处理时间内，观察到四种对映体在叶绿素 a（Chl a）含量、类胡萝卜素、光化学效率（F/F）、快速光响应曲线（RLCs）、光能利用效率（α）和蛋白质含量方面存在显著差异。MEZ 可以对映选择性地刺激 M. flos-aquae 的叶绿素荧光参数（RLCs、F/F 和 α）和类胡萝卜素和 Chl a 含量，尤其是在低浓度（0.001 或 0.003 mg/L）时。在高浓度（0.03 或 0.1 mg/L）时，暴露于顺式对映体的 M. flos-aquae 的叶绿素荧光参数（RLCs、F/F 和 α）、蛋白质和 Chl a 含量均低于暴露于反式对映体的 M. flos-aquae。这些观察结果表明，MEZ 的对映体对 M. flos-aquae 具有不同的毒性，顺式对映体比反式对映体更具毒性。这些结果有助于理解 MEZ 对映体对非靶标生物的对映选择性影响，并有助于评估它们的生态环境风险。
