University of Chinese Academy of Sciences, Beijing 100049, PR China; State Key Laboratory of Urban and Regional Ecology, Research Center for Eco-environmental Sciences, Chinese Academy of Sciences, Beijing 100085, PR China.
University of Chinese Academy of Sciences, Beijing 100049, PR China; State Key Laboratory of Urban and Regional Ecology, Research Center for Eco-environmental Sciences, Chinese Academy of Sciences, Beijing 100085, PR China.
Sci Total Environ. 2018 Jan 1;610-611:657-665. doi: 10.1016/j.scitotenv.2017.07.265. Epub 2017 Aug 17.
This study aimed to investigate the eco-toxicological responses of earthworm (Eisenia fetida) exposed to combined siduron (herbicide) and cadmium (Cd). Eisenia fetida gene expressions including metallothionein (MT) and heat shock protein70 (Hsp70) were analyzed using real-time Polymerase Chain Reaction after individual and combined siduron (0.90, 1.80, 3.60 and 7.20μgcm) and Cd (0.225, 0.45, 0.90 and 1.80μgcm) sublethal exposures. Where, the nature of the toxicological interactions between siduron and Cd in inducing or suppressing MT and Hsp70 expression was determined by applying the Combination index (CI)-isobologram model. The results revealed significant variations in MT and weak changes in Hsp70 expression when the earthworms were exposed to individual Cd. The individual siduron exposure exhibited a significant down-regulation (p<0.01) in MT during all treatments and in Hsp70 expression only at 7.20μgcm concentration; while the mixtures of siduron and Cd exposures resulted a significant down regulation (p<0.05) in both MT and Hsp70 expressions. Moreover, the combined siduron and Cd exposure revealed nearly additive effect (CI=1) at the lower effect levels and significant synergistic effect (CI<1) at the higher effect levels for both MT and Hsp70 expression. The synergistic effects of combined siduron and Cd suggest that there might be a potential risk connected to the co-occurrence of these chemicals in the environment.
本研究旨在探讨蚯蚓（赤子爱胜蚓）暴露于除草剂敌草隆和镉的联合胁迫下的生态毒理学响应。采用实时聚合酶链反应技术，分析了蚯蚓金属硫蛋白（MT）和热休克蛋白 70（Hsp70）基因的表达情况，实验分别进行了敌草隆（0.90、1.80、3.60 和 7.20μgcm）和镉（0.225、0.45、0.90 和 1.80μgcm）的单一和联合亚致死暴露。应用组合指数（CI）-等对数模型确定了敌草隆和镉在诱导或抑制 MT 和 Hsp70 表达方面的毒理学相互作用性质。结果表明，蚯蚓单独暴露于镉时，MT 表达发生显著变化，Hsp70 表达变化微弱。单独敌草隆暴露时，所有处理组 MT 均显著下调（p<0.01），仅在 7.20μgcm 浓度时 Hsp70 表达下调；而敌草隆和镉混合物暴露时，MT 和 Hsp70 表达均显著下调（p<0.05）。此外，敌草隆和镉联合暴露在较低效应水平下表现出近加性效应（CI=1），在较高效应水平下表现出显著协同效应（CI<1），对 MT 和 Hsp70 表达均如此。敌草隆和镉的协同效应表明，这些化学物质在环境中同时存在可能存在潜在风险。
