近年来我国耕地重金属污染形势相当严峻。探明水稻对重金属吸收、转运及耐性分子生理机制，对保障水稻安全生产意义重大。miRNA是一类新型的基因表达调控因子，在植物逆境胁迫应答过程中发挥重要作用。然而有关miRNA在重金属胁迫应答中的具体作用机制并不清楚。本项目以水稻中花11为材料，前期研究获知的与镉胁迫应答相关的miR390及其靶基因——富含亮氨酸的类受体蛋白激酶（Receptor-like protein kinase，RLK，Os02g10100）为研究对象，分析miR390及RLK的组织时序表达模式和亚细胞定位，采用转基因手段验证其功能，明确与重金属转运及解毒相关的RLK作用的下游底物，探究它们参与调控水稻对镉转运的具体分子生物学途径，掌握miR390对水稻镉胁迫应答的调控机制，为揭示水稻对重金属耐性分子机制提供理论依据，也为水稻重金属耐性遗传改良提供有效手段。

Heavy metal contamination of agricultural soils has become increasingly serious in China in recent years. To realize safe production of rice in heavy metal polluted soils, it is necessary to clarify the molecular and physiological mechanisms of heavy metal uptake, translocation and response in rice. miRNAs, an important new class of modulators of gene expression, play important roles in plant adaptations to environmental stresses. However, the knowledge of the specific role of miRNAs in heavy metal stress response is limited. In our previous study, miR390 and its target gene a receptor-like protein kinase (RLK) (Os02g10100) were identified to be Cd-responsive. In this study, Japonica rice Zhonghua 11 is used for test material. The temporal and tissue expression patterns, and subcellular localization of miR390 and RLK will be tested. Rice transgenic technology will be used to investigate their function. Furthermore, the downstream target gene of RLK will be identified. The specific regulatory pathway of miR390 and its target gene RLK in Cd translocation in rice will be investigated. These results will provide a new insight into understanding the molecular mechanism of heavy metal stress response in rice, and an effective strategy for the genetic improvement in rice heavy metal tolerance.