Key Laboratory of Pollution Processes and Environmental Criteria, Ministry of Education, Tianjin Key Laboratory of Environmental Remediation and Pollution Control, College of Environmental Science and Engineering, Nankai University, Tianjin 300350, PR China.
Key Laboratory of Pollution Processes and Environmental Criteria, Ministry of Education, Tianjin Key Laboratory of Environmental Remediation and Pollution Control, College of Environmental Science and Engineering, Nankai University, Tianjin 300350, PR China.
Sci Total Environ. 2019 Apr 15;661:767-777. doi: 10.1016/j.scitotenv.2019.01.181. Epub 2019 Jan 15.
This study aims to assess the role of iron plaque (IP) on cerium (Ce) uptake and translocation by rice after CeO nanoparticles (NPs) exposure over a 4 days period. A hydroponic experiment was performed under two IP levels (low and high) combined with two CeO NPs size (14 nm and 25 nm). It was found that CeO NPs as the main form was absorbed by rice due to limited NPs dissolution in hydroponic solution. IP significantly reduced surface-Ce, root-Ce and shoot-Ce accumulation, irrespective of CeO NPs sizes. The reduced uptake of Ce was more obvious in NP than NP. Ce accumulations decreased with increasing IP amounts. In IP treatments, the interactive attraction between NPs and root surface was weakened through the enhancement of hydrodynamic diameters and the reduction of ζ-potential of CeO NPs in solution, as well as the reduction of |ζ| values of rice root, which reduced the Ce bioaccumulation in rice. PCA indicated the negative correlation between surface-Ce (IP-C-Ce and IP-A-Ce) and NPs size, and between shoot-Ce/root-Ce and IP-Fe/tissue-Fe. IP also decreased Ce translocation from root to shoot. A full life study indicated the reduction effect of IP on surface-Ce, root-Ce, shoot-Ce and grain-Ce accumulations. These findings are significant as they imply that the IP formation is a promising approach for preventing Ce accumulation in rice, which would regulate Ce uptake by rice in the following growth stages and decrease the health risk of CeO NPs exposure in agricultural environment.
本研究旨在评估铁斑（IP）在铈（Ce）经 CeO 纳米颗粒（NPs）暴露后 4 天内被水稻吸收和转运的作用。在两个 IP 水平（低和高）和两个 CeO NPs 尺寸（14nm 和 25nm）下进行了水培实验。结果发现，CeO NPs 主要以纳米颗粒的形式被水稻吸收，因为纳米颗粒在水培溶液中的溶解有限。IP 显著降低了表面 Ce、根 Ce 和地上部 Ce 的积累，而与 CeO NPs 尺寸无关。与 NP 相比，NP 中的 Ce 吸收减少更为明显。随着 IP 量的增加，Ce 的积累减少。在 IP 处理中，通过增强纳米颗粒和根表面之间的相互吸引，增加溶液中 CeO NPs 的水动力直径和减少 ζ 电位，以及降低水稻根的 |ζ| 值，减少了 Ce 在水稻中的生物累积，从而降低了 Ce 的吸收。PCA 表明表面 Ce（IP-C-Ce 和 IP-A-Ce）与 NPs 尺寸之间，以及地上部 Ce/根 Ce 与 IP-Fe/组织-Fe 之间呈负相关。IP 还降低了 Ce 从根部向地上部的转运。一项全生命周期研究表明，IP 对表面 Ce、根 Ce、地上部 Ce 和籽粒 Ce 积累的减少作用。这些发现意义重大，因为它们意味着 IP 的形成是一种有前途的方法，可以防止 Ce 在水稻中的积累，从而在后续的生长阶段调节水稻对 Ce 的吸收，并降低农业环境中 CeO NPs 暴露的健康风险。
