State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, 163 Xianlin Avenue, Nanjing, 210023, China; State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, 73 East Beijing Road, Nanjing, 210008, China; Jiangsu Provincial Key Laboratory of Environmental Engineering, Jiangsu Provincial Academy of Environmental Science, 176 North Jiangdong Road, Nanjing, 210036, China.
Jiangsu Provincial Key Laboratory of Environmental Engineering, Jiangsu Provincial Academy of Environmental Science, 176 North Jiangdong Road, Nanjing, 210036, China.
Toxicon. 2020 Oct 30;186:151-159. doi: 10.1016/j.toxicon.2020.08.008. Epub 2020 Aug 14.
Heavy metals and microcystins commonly co-exist in water bodies with cyanobacteria, and have been shown to affect aquatic plants. However, their combined effects remain largely unknown. In this study, the toxic effects of copper (Cu) and cadmium (Cd) on Ceratophyllum demersum L. were characterized in the presence of microcystin-LR (MC-LR). The results showed that the bioaccumulation of MC-LR and Cu/Cd in C. demersum was significantly increased by the interaction between MC-LR and Cu/Cd. The combined toxicity assessment results suggested that the toxicities of Cu or Cd to C. demersum would be largely exacerbated by MC-LR, which could be the results of increased bioaccumulation of the pollutants. Cu, Cd and MC-LR, as well as their mixture, significantly decreased plant fresh weight and total chlorophyll content of C. demersum, especially at their high concentrations. The antioxidative system was activated to cope with the adverse effects of oxidative stress. Antioxidant enzyme activities were significantly stimulated by Cu, Cd and MC-LR, as well as their mixture. However, the decreased superoxide dismutase (SOD) and glutathione reductase (GR) activities were observed when exposed to relative high concentrations of Cu or Cd together with MC-LR of 5 μg L. MC-LR brought more stress to the antioxidative system, which is another possible explanation for the synergistic effect. Our findings highlight increased ecological risks of the co-contamination of heavy metals and harmful cyanobacteria.
重金属和微囊藻毒素通常共同存在于含有蓝藻的水体中，并已被证明会对水生植物产生影响。然而，它们的联合效应在很大程度上仍然未知。在这项研究中，在存在微囊藻毒素-LR（MC-LR）的情况下，研究了铜（Cu）和镉（Cd）对金鱼藻（Ceratophyllum demersum L.）的毒性作用。结果表明，MC-LR 与 Cu/Cd 之间的相互作用显著增加了 MC-LR 在金鱼藻中的生物积累。联合毒性评估结果表明，MC-LR 会大大加剧 Cu 或 Cd 对金鱼藻的毒性，这可能是由于污染物的生物积累增加所致。Cu、Cd 和 MC-LR 及其混合物显著降低了金鱼藻的鲜重和总叶绿素含量，尤其是在高浓度下。抗氧化系统被激活以应对氧化应激的不利影响。Cu、Cd 和 MC-LR 以及它们的混合物显著刺激了抗氧化酶的活性。然而，当暴露于相对高浓度的 Cu 或 Cd 与 5μg L 的 MC-LR 时，观察到超氧化物歧化酶（SOD）和谷胱甘肽还原酶（GR）活性降低。MC-LR 给抗氧化系统带来了更大的压力，这是协同效应的另一种可能解释。我们的研究结果强调了重金属和有害蓝藻共同污染增加的生态风险。
