拟南芥近缘种鼠耳芥是典型的超富集植物，具有极强的锌/镉耐受性和累积能力。鼠耳芥ARGONAUTE2/5（AGO2/5）蛋白是RNA沉默复合体的重要成员。转录组分析显示鼠耳芥AGO2/5表达水平分别远高于拟南芥，在拟南芥中过表达AGO2/5显著提高了其细胞的锌/镉耐受和累积能力。目前有关AGO蛋白-miRNA模块在植物锌/镉耐受性和超富集中的作用及调控机制不清楚。基于此，本研究拟在鼠耳芥中研究AGO2/5在植物锌/镉耐受性和超富集中的作用机制，包括1）分析AGO2/5组织表达模式及亚细胞定位，利用RNAi和过表达系确定AGO2/5对锌/镉耐受和累积的作用；2）利用RNAi和过表达系开展小RNA表达谱和转录组分析，并结合免疫沉淀结果，分析AGO2/5及其介导的miRNA参与调控锌/镉耐受和累积的作用网络。上述结果将促进植物重金属适应性调控机制的解析，为改良植物重金属环境适应能力提供理论依据。

Arabidopsis halleri, a close species of Arabidopsis thaliana, is a typical hyperaccumulator with strong tolerance and accumulation of Zn/Cd. ARGONAUTE2/5 function as a component of RNA-induced silencing complex (RISC) in A. halleri. Our transcriptome results revealed that AGO2/5 display significantly higher transcript abundance in A. halleri than their homologs in A. thaliana. More importantly, the A. thaliana cells overexpressing ARGONAUTE 2（AGO2）and AGO5 of A. halleri displayed significantly enhanced Zn/Cd tolerance and accumulation. The role and regulatory mechanisms of AGO-miRNA modules in Zn/Cd resistance and hyperaccumulation are currently unclear. Based on this, this study aims to demonstrate function and regulation of AGO2/5 in Zn/Cd tolerance and hyperaccumulation. 1) Gene expression patterns and subcellular localization firstly will be investigated. Phenotypic analysis will be performed using AGO2/5 RNAi and overexpressing lines to validate their roles in Zn/Cd tolerance and accumulation. 2) miRNA and transcript profiling using AGO2/5 RNAi and overexpressing lines as well as pull-down of AGO2/5-miRNA complex will reveal AGO2/5-mediated miRNA pathways that participate in regulatory network of Zn/Cd tolerance and accumulation in A. halleri. The results will benefit for dissecting regulatory mechanisms of heavy metal adaptions in plants and provide basic information for improving the performance of plants in heavy meal excessive environment.