College of Chemical Engineering, Beijing University of Chemical Technology, Beijing 100029, China; Key Laboratory for Biomedical Effects of Nanomaterials and Nanosafety, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China.
Key Laboratory for Biomedical Effects of Nanomaterials and Nanosafety, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China; School of Nuclear Science and Technology, University of Chinese Academy of Sciences, Beijing, 100049, China.
NanoImpact. 2021 Apr;22:100311. doi: 10.1016/j.impact.2021.100311. Epub 2021 Mar 26.
The release of toxic ions from metal-based nanoparticles (NPs) may play an important role in biological effects of NPs. In this life cycle study, physiological and biochemical responses of soil-grown corn (Zea mays) plants exposed to ceria NPs and its ionic counterparts Ce ions at 0, 25, 75 and 225 mg Ce/kg were investigated. Both treatments tended to reduce the fresh weight and height of the plants at 28 days after sowing (DAS), and delay silk appearance and finally decrease fruit weight at harvest. Uptake and distribution of some mineral nutrients, Ca, P, Fe, B, Zn and Mn in the plants were disturbed. None of the treatments significantly affected activities of antioxidant enzymes and MDA contents in the roots and leaves at 28 DAS. At 90 DAS, ceria NPs and Ce ions disturbed the homeostasis of antioxidative systems in the plants, Ce ions at all concentrations provoked significant oxidative damage in the roots and significantly increased MDA levels as compare to the control. The results indicate that the effects of ceria NPs and Ce ions on corn plants varied with different growth stages and ceria NPs had similar but less severe impacts than Ce ions. Speciation analysis revealed there was mutual transformation between CeO and Ce in the soil-plant system. It is speculated that Ce ions play a key role in toxicity. To the authors' knowledge, this is the first report of a life cycle study on comparative toxicity of CeO NPs and Ce ions on corn plants.
从基于金属的纳米粒子（NPs）中释放的有毒离子可能在 NPs 的生物效应中发挥重要作用。在这项生命周期研究中，研究了暴露于 CeO NPs 及其离子对应物 Ce 离子的土壤生长玉米（Zea mays）植物的生理和生化反应，浓度分别为 0、25、75 和 225 mg Ce/kg。两种处理都倾向于在播种后 28 天（DAS）降低植物的鲜重和高度，并延迟花丝出现，最终降低收获时的果实重量。植物中一些矿质营养元素的吸收和分布，如 Ca、P、Fe、B、Zn 和 Mn，受到干扰。在 28 DAS 时，没有一种处理显著影响根和叶中抗氧化酶的活性和 MDA 含量。在 90 DAS 时，CeO NPs 和 Ce 离子扰乱了植物抗氧化系统的动态平衡，所有浓度的 Ce 离子在根中引起了明显的氧化损伤，并显著增加了 MDA 水平，与对照相比。结果表明，CeO NPs 和 Ce 离子对玉米植物的影响因不同的生长阶段而不同，并且 CeO NPs 的影响与 Ce 离子相似，但程度较轻。形态分析表明，CeO 和 Ce 在土壤-植物系统中相互转化。据作者所知，这是首次报道关于 CeO NPs 和 Ce 离子对玉米植物比较毒性的生命周期研究。
