Genetic variation of the interaction type between two stressors in a single population: From antagonism to synergism when combining a heat spike and a pesticide. (1st September 2022)

• Record Type: Journal Article
• Authors: Delnat, Vienna; Verheyen, Julie; Van Hileghem, Ine; Stoks, Robby
• Is Part Of: Environmental pollution. Volume 308(2022)
• Publication Date: 2022-09-01
• Subjects: Climate-induced toxicant sensitivity' (CITS) -- Evolutionary ecotoxicology -- Global warming -- Stressor interaction patterns -- 'Toxicant-induced climate sensitivity' (TICS); CITS climate-induced toxicant sensitivity -- ERA ecological risk assessment -- fdr false discovery rate -- GC-ECD gas chromatography coupled with electron capture detector -- IA independent action -- MDR model deviation ratio -- OECD Organisation for Economic Co-operation and Development -- TICS toxicant-induced climate change sensitivity; Pollution -- Periodicals; Pollution -- Environmental aspects -- Periodicals; Environmental Pollution -- Periodicals; Pollution -- Périodiques; Pollution -- Aspect de l'environnement -- Périodiques; Pollution -- Effets physiologiques -- Périodiques; Pollution; Pollution -- Environmental aspects; Periodicals; Electronic journals; 363.73
• DOI: 10.1016/j.envpol.2022.119654
• Languages: English
• ISSNs: 0269-7491

Abstract

Abstract: Despite the surging interest in the interactions between toxicants and non-chemical stressors, and in evolutionary ecotoxicology, we have poor knowledge whether these patterns differ among genotypes within a population. Warming and toxicants are two widespread stressors in aquatic systems that are known to modify each other's effects. We studied to what extent effects of sequential exposure to a heat spike and the pesticide esfenvalerate differed among genotypes in the water flea Daphnia magna. Esfenvalerate had similar negative effects on survival and body size across genotypes, and for most genotypes it increased time to maturation, yet the effects on the reproductive performance were only detected in some genotypes and were inconsistent in direction. Across genotypes, the heat spike increased the heat tolerance, yet the negative effects of the heat spike on survival, reproductive performance and body size, and the positive effects on grazing rate and the shortened time to maturation were only seen in some genotypes. Notably, the interaction type between both stressors differed among genotypes. In contrast to our expectation, the impact of esfenvalerate was only magnified by the heat spike in some genotypes and only for a subset of the traits. For survival and time to maturation, the interaction type for the same stressor combination covered all three categories: additions, synergisms and antagonisms. This illustrates that categorizing the interaction type between stressors at the level of populations may hide considerable intrapopulation variation among genotypes. Opposite to our expectation, the more pesticide-tolerant genotypes showed a stronger synergism between both stressors. Genotype-dependent interaction patterns between toxicants and non-chemical stressors may explain inconsistencies among studies and challenges ecological risk assessment based on single genotypes. The observed genetic differences in the responses to the (combined) stressors may fuel the evolution of the stressor interaction pattern, a largely ignored topic in evolutionary ecotoxicology. Graphical abstract: Image 1 Highlights: Effects of a heat spike followed by a pesticide (esfenvalerate) pulse were studied. Daphnia magna genotypes differed in responses to both stressors. Genotypes differed in the interaction type for survival and time to maturation. More pesticide-tolerant genotypes showed a stronger synergism. Genetic variation allows evolution of the interaction type within a population.