Key Laboratory of Plant Resource Conservation and Germplasm Innovation in Mountainous Region (Ministry of Education), CollaborativeInnovation Center for Mountain Ecology & Agro-Bioengineering (CICMEAB), College of Life Sciences/Institute of Agro-Bioengineeringng, Guizhou University, Guiyang, 550025, Guizhou Province, China.
Institute of Geochemistry, Chinese Academy of Sciences, Guiyang, 550081, Guizhou Province, China.
Environ Sci Pollut Res Int. 2023 Sep;30(42):96181-96190. doi: 10.1007/s11356-023-29164-7. Epub 2023 Aug 11.
Cadmium (Cd) and polyethylene (PE) seriously contaminate the aquatic environment and threaten human health. Many studies have reported the toxic effects of Cd and PE on plants, whereas few have reported the combined contamination of these two pollutants. In this study, duckweed (Lemma minor) was used as an indicator to explore the effect of PE microplastics (PE-MPs) at concentrations of 10, 50, 100, 200, and 500 mg/L on tolerance to 1 mg/L Cd. The results showed that different concentrations of PE-MPs inhibited the growth rate and chlorophyll content of duckweed to different degrees, both of which were minimal at 50 mg/L PE-MPs, 0.11 g/d, and 0.32 mg/g, respectively. The highest Cd enrichment (7.77 mg/kg) and bioaccumulation factors (94.22) of duckweed were detected when Cd was co-exposed with 50 mg/L of PE-MPs. Catalase and peroxidase activity first decreased and then increased with increasing PE-MPs concentrations, showing "hormesis effects", with minimum values of 11.47 U/g and 196.00 U/g, respectively. With increasing concentrations of PE-MPs, the effect on superoxide dismutase activity increased and then declined, peaking at 162.05 U/g, and displaying an "inverted V" trend. The amount of malondialdehyde rose with different PE-MPs concentrations. This research lay a foundation for using duckweed to purify water contaminated with MPs and heavy metals.
镉 (Cd) 和聚乙烯 (PE) 严重污染水生环境，威胁人类健康。许多研究报告了 Cd 和 PE 对植物的毒性作用，而很少有研究报告这两种污染物的联合污染。本研究以浮萍 (Lemma minor) 为指示物，探讨了浓度为 10、50、100、200 和 500mg/L 的聚乙烯微塑料 (PE-MPs) 对耐受 1mg/L Cd 的影响。结果表明，不同浓度的 PE-MPs 对浮萍的生长率和叶绿素含量有不同程度的抑制作用，在 50mg/L 的 PE-MPs 时，抑制作用最小，分别为 0.11g/d 和 0.32mg/g。当 Cd 与 50mg/L 的 PE-MPs 共同暴露时，浮萍的 Cd 富集量 (7.77mg/kg) 和生物积累系数 (94.22) 最高。过氧化氢酶和过氧化物酶活性随 PE-MPs 浓度的增加先降低后升高，表现出“兴奋效应”，最小值分别为 11.47U/g 和 196.00U/g。随着 PE-MPs 浓度的增加，超氧化物歧化酶活性的影响先增加后降低，在 162.05U/g 时达到峰值，并呈现出“倒 V”趋势。丙二醛的含量随不同浓度的 PE-MPs 而增加。这项研究为利用浮萍净化受 MPs 和重金属污染的水奠定了基础。
