根表铁膜对水稻吸收运输氧化铜纳米颗粒的影响及其调控机制研究

农田土壤正逐渐成为金属纳米颗粒在环境中的主要沉积库，金属纳米颗粒可以被农作物吸收运输进入食物链，危害人体健康。但目前对于如何控制纳米材料的植物吸收研究还鲜有报道。水稻根系表面形成的根表铁膜是污染物进入植物体内的门户，可通过调控污染物结合形态保护植物根系。本项目拟通过室内模拟实验，以水稻根表铁膜为切入点，以典型金属纳米颗粒——氧化铜纳米颗粒为目标污染物，重点利用同步辐射软、硬X射线光谱技术结合微结构分析方法从微米尺度和纳米尺度开展研究，弄清根表铁膜形成对水稻吸收累积氧化铜纳米颗粒的影响，明确根表铁膜与氧化铜纳米颗粒微界面反应特征，揭示根表铁膜改变氧化铜纳米颗粒植物吸收方式和运输途径的关键机制，从而阐明根表铁膜对水稻吸收运输金属纳米颗粒的影响及其调控机制，对于科学评估金属纳米颗粒污染风险和保障农产品安全具有重要意义。

Agricultural soil is gradually becoming a primary sink for metal-based nanoparticles (MNPs). MNPs can be absorbed and translocated by crops and further enter the food chain, which may pose a threat to the human health. However, few studies have been reported on how to control the uptake of MNPs by plants so far. The iron plaque formed on the surface of rice roots is the gateway of pollutants into the plant, which can protect the roots via transforming the speciation of pollutants. In this project, we will study the interaction between iron plaque and copper oxide nanoparticles (CuO NPs) at micro- and nanoscale using synchrotron radiation soft and hard X-ray spectroscopy combined with other microstructure analysis methods. The main aims of this work are to investigate the effect of iron plaque on the uptake and accumulation of CuO NPs by rice plants, probe the characteristics of the micro-interface reaction between iron plaque and CuO NPs, explore the critical mechanism of the iron plaque altering the absorption pattern and translocation pathway of CuO NPs in rice plants, and thus clarify the effect of iron plaque on the uptake and translocation of CuO NPs by rice plants and its regulatory mechanism. This work should be of great significance for scientifically assessing the risk of MNP contamination and ensuring the safety of agricultural products.