College of Ecology and Environment, Chengdu University of Technology, Chengdu 610059, PR China.
College of Ecology and Environment, Chengdu University of Technology, Chengdu 610059, PR China; Tianfu Yongxing Laboratory, Chengdu 610213, PR China.
J Hazard Mater. 2023 Oct 5;459:132193. doi: 10.1016/j.jhazmat.2023.132193. Epub 2023 Jul 29.
Perfluorooctanoic acid (PFOA) and microcystin-LR (MCLR) are pervasive pollutants in surface waters that induce significant toxic effects on aquatic organisms. However, the combined environmental risk of PFOA and MCLR remains unclear. To assess the toxic effects of PFOA and MCLR on submerged macrophytes and biofilms, Vallisneria natans was exposed to different concentrations of PFOA and MCLR (0.01, 0.1, 1.0 and 10.0 μg L). Vallisneria natans was sensitive to high concentrations of MCLR (10 μg L): plants exposed to 10 μg L of MCLR measured a biomass of 3.46 g, which was significantly lower than the 8.71 g of the control group. Additionally, antagonistic interactive effects were observed in plants exposed to combined PFOA and MCLR. Exposure to these pollutants adversely affected photosynthesis of the plants and triggered peroxidation that promoted peroxidase, superoxide dismutase and catalase activities, and increased malondialdehyde and glutathione concentrations. The total chlorophyll content was lower in the highest concentration of the combined treatment group (0.443 mg g) than in the control group (0.534 mg g). Peroxidase activity increased from 662.63 U mg Pr to 1193.45 U mg Pr with increasing PFOA concentrations. Metabolomics indicated that the stress tolerance of Vallisneria natans was improved via altered fatty acid metabolism, hormone metabolism and carbon metabolism. Furthermore, PFOA and MCLR influenced the abundance and structure of the microbial community in the biofilms of Vallisneria natans. The increased contents of autoinducer peptide and N-acylated homoserine lactone signaling molecules indicated that these pollutants altered the formation and function of the biofilm. These results expand our understanding of the combined effects of PFOA and MCLR in aquatic ecosystems.
全氟辛酸 (PFOA) 和微囊藻毒素-LR (MCLR) 是地表水中普遍存在的污染物，对水生生物具有显著的毒性作用。然而，PFOA 和 MCLR 的联合环境风险尚不清楚。为了评估 PFOA 和 MCLR 对沉水植物和生物膜的毒性影响，采用不同浓度的 PFOA 和 MCLR (0.01、0.1、1.0 和 10.0μg/L) 对苦草进行暴露实验。苦草对高浓度的 MCLR (10μg/L) 较为敏感：暴露于 10μg/L MCLR 的植物的生物量为 3.46g，明显低于对照组的 8.71g。此外，在同时暴露于 PFOA 和 MCLR 的植物中观察到拮抗的交互作用。这些污染物的暴露对植物的光合作用产生了不利影响，并引发了过氧化作用，从而促进了过氧化物酶、超氧化物歧化酶和过氧化氢酶的活性，并增加了丙二醛和谷胱甘肽的浓度。在联合处理组的最高浓度(0.443mg/g)中，总叶绿素含量低于对照组(0.534mg/g)。过氧化物酶活性随着 PFOA 浓度的增加从 662.63Umg Pr 增加到 1193.45Umg Pr。代谢组学表明，苦草通过改变脂肪酸代谢、激素代谢和碳代谢来提高其对胁迫的耐受能力。此外，PFOA 和 MCLR 影响了苦草生物膜中微生物群落的丰度和结构。自动诱导肽和 N-酰化高丝氨酸内酯信号分子含量的增加表明，这些污染物改变了生物膜的形成和功能。这些结果扩展了我们对水生生态系统中 PFOA 和 MCLR 联合效应的理解。
