Nanoplastics, as emerging pollutants, have attracted worldwide concern for their possible environmental dangers. The ingestion and accumulation of nanoplastics in crops can contaminate the food chain and have unintended consequences for human health. In this study, we revealed the effects of polystyrene nanoplastics (PS-NPs; 80 nm) at different concentrations (0, 10, 100 mg L−1) on soybean (Glycine max L.) seedling growth, antioxidant enzyme system and secondary metabolism. Using laser confocal microscopy, we demonstrated that the absorption and translocation of PS-NPs in soybean. Plant growth inhibition was observed by changes in plant height, root length, and leaf area after 7 days of exposure to PS-NPs. The effect of PS-NPs on photosynthetic characteristics was reflected by a significant reduction in total chlorophyll content at 10 mg L−1. Activation of the antioxidant system was observed with increased malondialdehyde (MDA) content, and elevated activities of superoxide dismutase (SOD) and catalase (CAT). Non-targeted metabolomics analysis identified a total of 159 secondary metabolites, and exposure to 10 and 100 mg L−1 PS-NPs resulted in the production of 61 and 62 differential secondary metabolites. Metabolomics analysis showed that PS-NPs treatment altered the secondary metabolic profile of soybean leaves through the biosynthesis pathways of flavonoid, flavone flavonol, and isoflavones, which is expected to provide new insights into the tolerance mechanisms of plants to nanoplastics. Overall, the results of this study deepen our understanding of the negative impacts of nanoplastics in agricultural systems, which is crucial for assessing the risks of nanoplastics to ecological security.

中文翻译：

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聚苯乙烯纳米塑料对大豆 （Glycine max L.） 的毒理学影响和分子代谢：通过增强次生代谢增强防御能力


纳米塑料作为新兴污染物，因其可能对环境造成的危害而引起了全世界的关注。农作物中纳米塑料的摄入和积累会污染食物链，并对人类健康产生意想不到的后果。在这项研究中，我们揭示了不同浓度 （0、10、100 mg L-1） 的聚苯乙烯纳米塑料 （PS-NPs;80 nm） 对大豆 （Glycine max L.） 幼苗生长、抗氧化酶系统和次生代谢的影响。使用激光共聚焦显微镜，我们证明了大豆中 PS-NPs 的吸收和易位。暴露于 PS-NPs 7 天后，通过植物高度、根长和叶面积的变化观察到植物生长抑制。PS-NPs 对光合特性的影响反映在 10 mg L-1 时总叶绿素含量显著降低。随着丙二醛 （MDA） 含量的增加以及超氧化物歧化酶 （SOD） 和过氧化氢酶 （CAT） 活性的升高，观察到抗氧化系统的激活。非靶向代谢组学分析共鉴定了 159 种次生代谢物，暴露于 10 和 100 mg L-1 PS-NPs 导致产生 61 和 62 种不同的次生代谢物。代谢组学分析表明，PS-NPs 处理通过类黄酮、黄酮、黄酮和异黄酮的生物合成途径改变了大豆叶片的次生代谢特征，有望为植物对纳米塑料的耐受性机制提供新的见解。总体而言，本研究的结果加深了我们对纳米塑料对农业系统的负面影响的理解，这对于评估纳米塑料对生态安全的风险至关重要。