CFE - Centre for Functional Ecology, Department of Life Sciences, University of Coimbra, Calçada Martim de Freitas, 3000-456 Coimbra, Portugal.
IMAR - Instituto do Mar, Department of Life Sciences, University of Coimbra, Calçada Martim de Freitas, 3000-456 Coimbra, Portugal.
Chemosphere. 2015 Aug;132:127-34. doi: 10.1016/j.chemosphere.2015.03.011. Epub 2015 Mar 30.
Research on the effects of thermal stress is currently pertinent as climate change is expected to cause more severe climate-driven events. Carcinus maenas, a recognised estuarine model organism, was selected to test temperature-dependence of azoxystrobin toxicity, a widely applied fungicide. Crabs' responses were assessed after a 10-d acclimation at different temperatures (5°C, 22°C, and 27°C) of which the last 72h were of exposure to an environmental concentration of azoxystrobin. SOD and GST activities, mitochondrial oxygen consumption rates and protein content, as well as the Coupling Index were determined. The hypothesis proposed that extreme temperatures (5°C and 27°C) and azoxystrobin would affect crabs' responses. Results showed statistically significant different effects of SOD and all oxygen rates measured promoted by temperature, and that neither 30.3μgL(-1) of azoxystrobin nor the combined effect were crab-responsive. Protein content at 5°C was statistically higher when compared with the control temperature (22°C). The Coupling Index revealed both a slight and a drastic decrease of this index promoted by 5°C and 27°C, respectively. Regarding azoxystrobin effects, at 22°C, this index only decreased slightly. However, at extreme temperatures it fell 47% at 5°C and slightly increased at 27°C. Results provided evidence that crabs' responses to cope with low temperatures were more effective than their responses to cope with high temperatures, which are expected in future climate projections. Moreover, crabs are capable of handling environmental concentrations of azoxystrobin. However, the Coupling Index showed that combined stress factors unbalance crabs' natural capability to handle a single stressor.
目前，研究热应激的影响是相关的，因为预计气候变化将导致更严重的气候驱动事件。三疣梭子蟹是一种公认的河口模式生物，被选来测试嘧菌酯毒性的温度依赖性，嘧菌酯是一种广泛应用的杀菌剂。在不同温度（5°C、22°C 和 27°C）下适应 10 天后，评估了螃蟹的反应，其中最后 72 小时暴露于嘧菌酯的环境浓度中。测定了 SOD 和 GST 活性、线粒体耗氧率和蛋白质含量以及耦合指数。提出的假设是，极端温度（5°C 和 27°C）和嘧菌酯会影响螃蟹的反应。结果表明，温度显著影响 SOD 和所有测量的耗氧率，30.3μgL(-1)的嘧菌酯和组合效应都没有引起螃蟹的反应。与对照温度（22°C）相比，5°C 时蛋白质含量统计学上更高。耦合指数显示，5°C 和 27°C 分别轻微和剧烈降低了该指数。关于嘧菌酯的影响，在 22°C 时，该指数仅略有下降。然而，在极端温度下，它在 5°C 时下降了 47%，在 27°C 时略有增加。结果表明，螃蟹应对低温的反应比应对高温的反应更有效，而高温预计将是未来气候预测的结果。此外，螃蟹能够处理嘧菌酯的环境浓度。然而，耦合指数表明，综合应激因素破坏了螃蟹应对单一应激源的自然能力。
