College of Land and Environment, Shenyang Agricultural University, Shenyang 110866, China.
Shenyang Academy of Environmental Sciences, Shenyang 110016, China; State Key Laboratory of Urban and Regional Ecology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China.
Ecotoxicol Environ Saf. 2020 Sep 1;200:110728. doi: 10.1016/j.ecoenv.2020.110728. Epub 2020 May 24.
In this study, the effects of iron (Fe) nanoparticles (NPs) on Fe and heavy metal accumulations by castor (Ricinus communis L.) plants were investigated. The castor cultivar was planted in the soil contaminated with Pb and Zn for 48 days with FeO NPs treatments. The Fe and heavy metal concentrations in the plant tissues, the plant tissues' ultrastructures, and the Fe and heavy metal distributions in the soil aggregate were analyzed. The results of this study indicate that there is a mutual promotion relationship between Fe and heavy metals (Pb and Zn). The scanning electron microscopy (SEM) revealed ultrastructural differences in the xylem and phloem with FeO NPs addition, and the presence of FeO NPs may influence the synthesis of starch granules in response to heavy metal stress. Based on the analysis of the soil aggregate, α-FeO NPs and γ-FeO NPs changed the size distribution of the soil aggregate, that is, the macro-aggregate and the clay fraction contents increased and the micro-aggregate content decreased. Moreover, in the different size fractions of the soil aggregate, FeO NPs can change the Zn and Fe enrichment and migration between the macro-aggregate and clay fractions, and there is a synergistic effect between the Fe and Zn migration. In addition, in the castor organs (roots and shoots), the Zn accumulation was mainly determined by the Zn concentration of the macro-aggregate fraction, while the Fe accumulation was mainly determined by the Fe concentration of the micro-aggregate fraction. Overall, these direct observations help improve our understanding of the migration and transport characteristics of Fe and heavy metals in soil-plant systems when Fe nanoparticles are added to metal-contaminated soils.
在这项研究中，研究了铁纳米颗粒（Fe NPs）对蓖麻（Ricinus communis L.）植物中铁和重金属积累的影响。将蓖麻品种种植在受 Pb 和 Zn 污染的土壤中 48 天，并进行 FeO NPs 处理。分析了植物组织中的 Fe 和重金属浓度、植物组织的超微结构以及土壤团聚体中 Fe 和重金属的分布。研究结果表明，Fe 和重金属（Pb 和 Zn）之间存在相互促进的关系。扫描电子显微镜（SEM）显示，添加 FeO NPs 后木质部和韧皮部的超微结构存在差异，而 FeO NPs 的存在可能会影响淀粉颗粒的合成以应对重金属胁迫。基于土壤团聚体的分析，α-FeO NPs 和 γ-FeO NPs 改变了土壤团聚体的粒径分布，即大团聚体和粘粒含量增加，微团聚体含量减少。此外，在土壤团聚体的不同粒径分级中，FeO NPs 可以改变 Zn 和 Fe 在大团聚体和粘粒之间的富集和迁移，Fe 和 Zn 的迁移存在协同效应。此外，在蓖麻器官（根和茎）中，Zn 的积累主要取决于大团聚体分级中的 Zn 浓度，而 Fe 的积累主要取决于微团聚体分级中的 Fe 浓度。总的来说，这些直接观察有助于提高我们对添加 Fe 纳米颗粒到受金属污染土壤中时，土壤-植物系统中 Fe 和重金属迁移和运输特性的理解。
