College of Ecology and Environment, Hainan University, Haikou, 570228, PR China; Environmental and Plant Protection Institute, Chinese Academy of Tropical Agricultural Sciences, Hainan Danzhou Tropical Agro-ecosystem National Observation and Research Station, Key Laboratory of Low-carbon Green Agriculture in Tropical Region of China, Ministry of Agriculture and Rural Affairs, Danzhou, 571737, PR China.
Environmental and Plant Protection Institute, Chinese Academy of Tropical Agricultural Sciences, Hainan Danzhou Tropical Agro-ecosystem National Observation and Research Station, Key Laboratory of Low-carbon Green Agriculture in Tropical Region of China, Ministry of Agriculture and Rural Affairs, Danzhou, 571737, PR China; Hainan Key Laboratory of Tropical Eco-Circuling Agriculture, Haikou, 571101, PR China.
Chemosphere. 2022 Nov;307(Pt 1):135714. doi: 10.1016/j.chemosphere.2022.135714. Epub 2022 Jul 13.
Nanoplastics (NPs) (<1 μm) have gradually attracted worldwide attention owing to their widespread occurrence, distribution, and ecosystem risks. Few studies have explored the interaction between NPs and heavy metals in crops. In this study, we investigated the influence of polystyrene nanoplastics (PSNPs; 10 mg/L and 100 mg/L) and cadmium (2 mg/L and 10 mg/L) on the physiological and biochemical indices of maize plants, grown in Hoagland solution with contaminants, for 14 days. The fresh weight and growth of the maize plants were significantly reduced after exposure to high concentrations of PSNPs and Cd (p < 0.05). Specifically, the fresh weight decreased by 30.3% and 32.5% in the PSNPs and Cd treatment, respectively. Root length and shoot length decreased by 11.7% and 20.0%, and by 16.3% and 27.8%, in the PSNPs and Cd treatment, respectively. However, there were no significant effects on the fresh weight and growth of maize plants as Cd levels increased from 2 to 10 mg/L in the presence of PSNPs. Polystyrene nanoplastics alleviated the phytotoxicity of Cd in maize. Scanning electron microscopy (SEM) showed that PSNPs and Cd could enter maize roots and were transported upwards to the leaves through the vascular bundle. The activities of peroxidase (POD) and catalase (CAT) in maize leaves increased significantly under high concentrations of PSNPs, whereas superoxide dismutase (SOD) activity decreased (p < 0.05). The differences in SOD activity may be related to the absence of microelements such as Zn, Fe, and Mn. This study provides a scientific basis for further exploration of the combined toxicological effects of heavy metals and NPs on the environment.
纳米塑料（NPs）（<1μm）由于其广泛存在、分布和生态系统风险而逐渐引起全球关注。很少有研究探讨 NPs 与农作物中重金属之间的相互作用。在这项研究中，我们研究了聚苯乙烯纳米塑料（PSNPs；10mg/L 和 100mg/L）和镉（2mg/L 和 10mg/L）对在含有污染物的 Hoagland 溶液中生长的玉米植株的生理生化指标的影响，共 14 天。暴露于高浓度 PSNPs 和 Cd 后，玉米植株的鲜重和生长明显受到抑制（p<0.05）。具体来说，PSNPs 和 Cd 处理组的鲜重分别降低了 30.3%和 32.5%。根长和茎长分别降低了 11.7%和 20.0%，16.3%和 27.8%，PSNPs 和 Cd 处理组。然而，在 PSNPs 存在的情况下，Cd 浓度从 2mg/L 增加到 10mg/L 时，对玉米植株的鲜重和生长没有显著影响。聚苯乙烯纳米塑料缓解了 Cd 对玉米的植物毒性。扫描电子显微镜（SEM）显示，PSNPs 和 Cd 可以进入玉米根，并通过维管束向上运输到叶片。在高浓度 PSNPs 下，玉米叶片中的过氧化物酶（POD）和过氧化氢酶（CAT）活性显著增加，而过氧化物歧化酶（SOD）活性降低（p<0.05）。SOD 活性的差异可能与 Zn、Fe 和 Mn 等微量元素的缺乏有关。本研究为进一步探索重金属和 NPs 对环境的联合毒性作用提供了科学依据。
