Abstract：
Aquatic ecosystems are facing increasing exposure to pollutants, posing potential threats to the stability and wellness of aquatic species. This study focused on evaluating the impacts of single and combined exposure to 80 nm polystyrene nanoplastics (PS-NPs, 0.1, 1, 10, 20 mg/L) and decabromodiphenyl ether (BDE-209, 300 ng/L) for 14 days on the bioaccumulation, growth, photosynthesis and oxidative stress in the free-floating fern Salvinia natans. PS-NPs primarily accumulated in the epidermis and trichomes of S. natans. Meanwhile, the levels of superoxide dismutase (SOD) and malondialdehyde (MDA) were significantly increased, while those for peroxidase (POD), catalase (CAT), total antioxidant capacity (T-AOC), and relative growth rate (RGR) decreased. Furthermore, the chlorophyll contents in submerged leaves were decreased, while those in floating leaves were increased at PS-NPs concentrations of 0.1 and 1 mg/L. However, the chlorophyll contents in both submerged and floating leaves displayed a decreasing trend with increasing concentrations of PS-NPs. Under the co-exposure of PS-NPs and BDE-209, the contents of MDA were significantly elevated, whereas CAT, POD, SOD, T-AOC and RGR were significantly decreased (p < 0.05). Our results revealed that, compared to single exposure, more pronounced ecotoxic effects are observed in S. natans under co-exposure to PS-NPs and BDE-209. These findings offer valuable perspectives into the possible environmental risks of BDE-209 and PS-NPs in freshwater ecosystems, contributing to the development of effective management strategies for protecting aquatic organisms and ecosystems. This research highlights the urgent need to understand the toxic effects of emerging contaminants on different aquatic organisms, emphasizing the importance of protecting and preserving aquatic ecosystems.
摘要：
水生生态系统正面临越来越多的污染物暴露，对水生物种的稳定和健康构成潜在威胁。这项研究的重点是评估单次和联合暴露于80nm聚苯乙烯纳米塑料(PS-NP，0.1、1、10、20mg/L)和十溴二苯醚(BDE-209，300ng/L)生物蓄积性14天，增长,自由漂浮蕨类植物的光合作用和氧化应激。PS-NP主要积累在S.natans的表皮和毛状体中。同时,超氧化物歧化酶(SOD)和丙二醛(MDA)含量显著升高,而过氧化物酶（POD），过氧化氢酶(CAT),总抗氧化能力(T-AOC)，相对增长率(RGR)下降。此外，沉水叶中的叶绿素含量下降，而在PS-NP浓度为0.1和1mg/L时，漂浮叶片中的含量增加。然而,随着PS-NP浓度的增加，淹没叶和漂浮叶的叶绿素含量均呈下降趋势。在PS-NP和BDE-209共同暴露下,MDA含量显著升高,而CAT,POD,SOD,T-AOC和RGR显著降低(p<0.05)。我们的结果显示,与单一曝光相比，在共同暴露于PS-NP和BDE-209的S.natans中观察到更明显的生态毒性效应。这些发现为淡水生态系统中BDE-209和PS-NPs可能存在的环境风险提供了宝贵的观点，有助于制定保护水生生物和生态系统的有效管理战略。这项研究强调了迫切需要了解新兴污染物对不同水生生物的毒性作用，强调保护和保存水生生态系统的重要性。
