State Key Laboratory of Environmental Aquatic Chemistry, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; Guangxi Key Laboratory of Environmental Pollution Control Theory and Technology, Guilin University of Technology, Guilin 541004, China.
State Key Laboratory of Environmental Aquatic Chemistry, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; University of Chinese Academy of Sciences, Beijing 100049, China.
J Hazard Mater. 2023 Jun 5;451:131140. doi: 10.1016/j.jhazmat.2023.131140. Epub 2023 Mar 4.
Nanoparticles have been found in large-scale environmental media in recent years, causing toxic effects in various organisms and even humans through food chain transmission. The ecotoxicological impact of microplastics on specific organisms is currently receiving much attention. However, relatively little research to date has examined the mechanisms through which nanoplastic residue may exert an interference effect on floating macrophytes in constructed wetlands. In our study, the aquatic plant Eichhornia crassipes was subjected to 100 nm polystyrene nanoplastics at concentrations of 0.1, 1 and 10 mg L after 28 days of exposure. E. crassipes can decrease the concentration of nanoplastics in water by 61.42∼90.81% through phytostabilization. The abiotic stress of nanoplastics on the phenotypic plasticity (morphological and photosynthetic properties and antioxidant systems as well as molecular metabolism) of E. crassipes was assessed. The presence of nanoplastics reduced the biomass (10.66%∼22.05%), and the functional organ (petiole) diameters of E. crassipes decreased by 7.38%. The photosynthetic efficiency was determined, showing that the photosynthetic systems of E. crassipes are very sensitive to stress by nanoplastics at a concentration of 10 mg L. Oxidative stress and imbalance of antioxidant systems in functional organs are associated with multiple pressure modes from nanoplastic concentrations. The catalase contents of roots increased by 151.19% in the 10 mg L treatment groups compared with the control group. Moreover, 10 mg L concentrations of the nanoplastic pollutant interfere with purine and lysine metabolism in the root system. The hypoxanthine content was reduced by 6.58∼8.32% under exposure to different concentrations of nanoplastics. In the pentose phosphate pathway, the phosphoric acid content was decreased by 32.70% at 10 mg L PS-NPs. In the pentose phosphate pathway, the phosphoric acid content was decreased by 32.70% at 10 mg L PS-NPs. Nanoplastics disturb the efficiency of water purification by floating macrophytes, which reduces the chemical oxygen demand (COD) removal efficiency (from 73% to 31.33%) due to various abiotic stresses. This study provided important information for further clarifying the impact of nanoplastics on the stress response of floating macrophytes.
近年来，纳米颗粒在大规模环境介质中被发现，通过食物链传播，对各种生物甚至人类产生了毒性影响。微塑料对特定生物的生态毒理学影响目前受到广泛关注。然而，迄今为止，相对较少的研究探讨了纳米塑料残留可能通过何种机制对人工湿地中的漂浮植物产生干扰效应。在我们的研究中，在暴露 28 天后，将水生植物凤眼莲用浓度为 0.1、1 和 10 mg/L 的 100nm 聚苯乙烯纳米塑料处理。凤眼莲通过植物稳定化作用可将水中纳米塑料的浓度降低 61.42%∼90.81%。评估了纳米塑料对凤眼莲表型可塑性（形态和光合特性以及抗氧化系统和分子代谢）的非生物胁迫。纳米塑料的存在降低了凤眼莲的生物量（10.66%∼22.05%），功能器官（叶柄）直径减小了 7.38%。测定了光合效率，表明在 10 mg/L 浓度下，纳米塑料对凤眼莲的光合系统产生了非常敏感的胁迫。功能器官中氧化应激和抗氧化系统失衡与纳米塑料浓度的多种压力模式有关。与对照组相比，10 mg/L 处理组的根中过氧化氢酶含量增加了 151.19%。此外，10 mg/L 浓度的纳米塑料污染物干扰了根系中嘌呤和赖氨酸的代谢。在不同浓度的纳米塑料暴露下，次黄嘌呤含量降低了 6.58%∼8.32%。在戊糖磷酸途径中，在 10 mg/L PS-NPs 时磷酸含量降低了 32.70%。纳米塑料干扰了漂浮植物的净水效率，由于各种非生物胁迫，化学需氧量（COD）去除效率（从 73%降至 31.33%）降低。本研究为进一步阐明纳米塑料对漂浮植物胁迫响应的影响提供了重要信息。
