我国南方土壤镉污染普遍，镉和锌化学性质相似，植物吸收锌和镉存在拮抗作用或协同作用。水稻具有较强的镉积累性，但是锌对水稻镉吸收转运过程影响的生理过程机制尚不明确。本项目采用金属稳定同位素分馏技术结合植物生理学和分子生物学的方法，系统解析锌缺乏和过量条件下水稻成熟期各组织的镉稳定同位素组成特征，明确锌对水稻组织水平镉同位素组成差异的影响机制；进一步解析水稻细胞壁和原生质体的镉稳定同位素组成特征，明确锌对水稻植株吸收转运镉不同途径的影响机制；从分子水平解析锌对水稻镉跨膜转运过程中迁移率和镉转运蛋白基因表达丰度的作用机制。最终明确锌影响下水稻成熟期镉同位素分馏的植物生理机制，系统阐释关键转运蛋白表达及其作用过程机制，揭示水稻籽粒镉积累的关键途径及影响因素。成果预期将丰富和拓展金属同位素分馏在土壤环境和植物学领域的应用，并为构建降低水稻籽粒镉积累的农艺调控措施提供理论支撑。

Soil cadmium (Cd) pollution is common in southern China and rice has a strong accumulation of Cd. Cd and Zinc (Zn) have similar chemical properties, the absorption of Zn and Cd in plants has both antagonistic and synergistic effects. However, the effect of Zn on the Cd absorption and transport in rice is still unclear. This project uses metal stable isotope fractionation techniques combined with plant physiology and molecular biology methods to investigate the Cd stable isotope composition of various tissues during rice maturity under Zn deficiency and pollution conditions, then clarify the effect of Zn on Cd isotopic fractionation in rice. Sequentially investigate the Cd stable isotope composition of cell wall and protoplast, then clarify the effect of Zn on Cd absorption pathway in rice. Meanwhile, the mechanism of Zn on rice cadmium transmembrane transport rate and cadmium transporter gene expression will be clarified. Finally, the effects of Zn on the major pathways of Cd absorption and isotope fractionation in rice will be clarified, and the key pathways and transporters for cadmium accumulation in rice grains will be identified. These results will enrich the application of metal isotopic fractionation in the field of soil environment and botany and provide theoretical support for reducing Cd accumulation in rice grains.