PDF(Pubmed)
Abstract：
Global change confronts organisms with multiple stressors causing nonadditive effects. Persistent stress, however, leads to adaptation and related trade-offs. The question arises: How can the resulting effects of these contradictory processes be predicted? Here we show that Gammarus pulex from agricultural streams were more tolerant to clothianidin (mean EC50 148 μg/L) than populations from reference streams (mean EC50 67 μg/L). We assume that this increased tolerance results from a combination of physiological acclimation, epigenetic effects, and genetic evolution, termed as adaptation. Further, joint exposure to pesticide mixture and temperature stress led to synergistic interactions of all three stressors. However, these combined effects were significantly stronger in adapted populations as shown by the model deviation ratio (MDR) of 4, compared to reference populations (MDR = 2.7). The pesticide adaptation reduced the General-Stress capacity of adapted individuals, and the related trade-off process increased vulnerability to combined stress. Overall, synergistic interactions were stronger with increasing total stress and could be well predicted by the stress addition model (SAM). In contrast, traditional models such as concentration addition (CA) and effect addition (EA) substantially underestimated the combined effects. We conclude that several, even very disparate stress factors, including population adaptations to stress, can act synergistically. The strong synergistic potential underscores the critical importance of correctly predicting multiple stresses for risk assessment.
摘要：
全球变化使生物体面临多种压力源，从而导致非加性效应。持续的压力，然而,导致适应和相关的权衡。问题出现了：如何预测这些矛盾过程的结果？在这里，我们表明来自农业流的Gammaruspulex比来自参考流的种群（平均EC5067μg/L）对噻虫胺（平均EC50148μg/L）更耐受。我们假设这种增加的耐受性来自生理适应的组合，表观遗传效应，和遗传进化，称为适应。Further,联合暴露于农药混合物和温度胁迫导致所有三种应激源的协同相互作用。然而,与参考人群(MDR=2.7)相比,模型偏差比(MDR)为4,在适应人群中,这些综合效应明显更强.农药适应降低了适应个体的一般应激能力，相关的权衡过程增加了对综合压力的脆弱性。总的来说,协同相互作用随着总胁迫的增加而增强，并且可以通过胁迫添加模型（SAM）很好地预测。相比之下,传统模型，如浓度添加(CA)和效应添加(EA)，大大低估了综合效应。我们得出结论，几个，即使是非常不同的压力因素，包括人口对压力的适应，可以协同行动。强大的协同潜力强调了正确预测多种压力以进行风险评估的至关重要性。
