镉是我国农田和稻米污染较为严重且普遍的主要重金属元素，已被世界卫生组织列为重点研究的食品污染物和人类致癌物。水杨酸（salicylic acid，SA）是备受关注的重要信号分子，在植物信号转导以及调控植物响应多种非生物胁迫中发挥着重要作用。本课题组前期研究表明外源施加SA可显著降低稻米中镉的含量且对其农艺性状无影响，但其调控稻米镉积累的具体生理分子机制尚不清楚。本项目将以稻米镉高积累的水稻品种秀水110、日本晴及其转SA水解酶的日本晴转基因株系为材料，采用盆栽与大田试验相结合，在1.0mg/kg 镉（国家三级污染标准）污染条件下，利用外源SA处理研究SA信号转导途径参与调控稻米中镉积累转运的具体作用机制。项目研究不仅为实现中轻度镉污染土壤上稻米的安全生产提供技术支撑，也为利用现代分子生物技术来培育可食部位镉低积累的作物新品种提供理论指导。

Cadmium, a major heavy metal pollution in farmland and rice grain in China, has been listed as the key research by the World Health Organization. Salicylic acid (SA) is an important signaling molecule, and plays an important role in plant signal transduction and regulation of plant responses to abiotic stresses. In the previous studies, our research results showed that exogenous SA could significantly reduce the content of cadmium in rice grain but had no effect on the agronomic traits of rice, but the specific physiological and molecular mechanism of SA regulating cadmium accumulation in rice grain is not yet clear. This project will use high grain-cadmium -accumulating rice cultivar Xiushui 110, Nipponbare and SA hydrolytic enzyme transgenic lines for experimental materials, and the pot and field experiments will be used with 1.0 mg/kg cadmium pollution condition, to investigate the specific mechanism of SA signal transduction pathway involving in the regulation of cadmium accumulation and translocation in rice grain under exogenous SA treatments. Thus, this project will provide technical support for the safety production of rice grain in mild cadmium contaminated soil, and provide theoretical guidance for the cultivation of new crop varieties with low cadmium accumulation in edible parts using the modern molecular biotechnology.