Laboratory of Evolutionary Stress Ecology and Ecotoxicology, University of Leuven, 3000 Leuven, Belgium.
Laboratory of Evolutionary Stress Ecology and Ecotoxicology, University of Leuven, 3000 Leuven, Belgium; Institute of Aquaculture, Nha Trang University, Khanh Hoa, Viet Nam.
Sci Total Environ. 2022 Jan 20;805:150373. doi: 10.1016/j.scitotenv.2021.150373. Epub 2021 Sep 16.
There is increasing awareness that the toxicity of pesticides can to a large extent be modulated by warming, and that temporal exposure scenarios may strongly affect the impact of two stressors. Nevertheless, we lack information on how the exposure duration to warming may shape pesticide toxicity under warming. Furthermore, despite that bioenergetic responses have the potential to generate mechanistic insights in how toxicants interact with warming, this has been understudied in ecotoxicology. To investigate whether warming duration modifies pesticide toxicity, mosquito larvae were exposed to a control temperature at 20 °C or three warming treatments at 24 °C (acute, developmental and transgenerational warming), and to four pesticide treatments (solvent control, and three chlorpyrifos concentrations) in a full factorial design. Chlorpyrifos increased mortality, growth rate and the energy consumed, and reduced the AChE (acetylcholinesterase) activity, the energy available, and the net energy budget (estimated as cellular energy allocation). The warming treatments did not affect mortality, AChE activity, and the energy consumed. However, acute warming increased the growth rate and decreased the energy available, while both acute and developmental warming decreased the cellular energy allocation. A first key finding was that the lethal and sublethal effects of chlorpyrifos were less strong under warming because of a higher degradation in the medium under warming. A second key finding was that, among the warming treatments, the pesticide toxicity was more increased under acute warming than under transgenerational warming. This could be explained by the negative impact of acute warming but not transgenerational warming on the net energy budget. The results in this study provide mechanistic insights that the exposure duration to warming can play an important role in modulating the impact of pesticides under warming. Therefore, including ecologically relevant temporal scenarios of exposure to warming is important in ecotoxicological studies.
人们越来越意识到，农药的毒性在很大程度上可以通过升温来调节，而且时间暴露情景可能会强烈影响两种胁迫因素的影响。然而，我们缺乏关于变暖期间暴露持续时间如何塑造农药毒性的信息。此外，尽管生物能量响应有可能为有毒物质与升温相互作用提供机制上的见解，但在生态毒理学中对此研究甚少。为了研究变暖持续时间是否会改变农药毒性，将蚊子幼虫暴露于 20°C 的对照温度或 24°C 的三种升温处理（急性、发育和跨代升温）中，并在完全析因设计中暴露于四种农药处理（溶剂对照和三种毒死蜱浓度）中。毒死蜱增加了死亡率、生长率和能量消耗，降低了乙酰胆碱酯酶（AChE）活性、可用能量和净能量预算（估计为细胞能量分配）。升温处理不会影响死亡率、AChE 活性和能量消耗。然而，急性升温提高了生长率并降低了可用能量，而急性和发育升温都降低了细胞能量分配。第一个关键发现是，由于升温下培养基中更高的降解，氯吡硫磷的致死和亚致死效应在升温下较弱。第二个关键发现是，在升温处理中，急性升温下农药毒性比跨代升温下增加得更多。这可以解释为急性升温的负面影响，但跨代升温对净能量预算没有影响。本研究的结果提供了机制上的见解，即暴露于升温的持续时间可以在调节升温下农药的影响方面发挥重要作用。因此，在生态毒理学研究中，包括与升温相关的生态时间暴露情景非常重要。
