前期鉴定了一个调控植物镉（Cd）积累和耐受的基因ATLx，其编码一个泛素E3连接酶。研究表明，atlx-1突变体对Cd敏感，且其体内Cd积累显著增加。初步研究发现，ATLx与一个涉及Cd吸收相关转运蛋白IRT1互作，暗示在Cd胁迫下ATLx可能通过IRT1的泛素化降解从而降低Cd吸收以增加植株Cd耐受性。此外，还筛选了一个可能直接调控ATLx基因转录的转录因子WRKYa，该基因敲除的突变体wrkya-1和wrkya-2对Cd胁迫敏感。本项目拟研究ATLx基因及其介导的上游和下游信号转导组分，解析其调控植物对Cd积累和耐受的机理，阐明一条植物对Cd胁迫响应的信号通路WRKYa-ATLx-IRT1。

We previously identified an Arabidopsis ATLx gene encoding a ubiquitin E3 ligase, which is involved in the regulation of cadmium (Cd) accumulation and tolerance in plants. We found that the atlx-1 mutant is Cd sensitive, and exhibits increased Cd content. Preliminary study showed that ATLx may interact with the IRT1 transporter involved in Cd uptake, suggesting that, in response of plants to Cd stress, ATLx may ubiquitinate IRT1 and target it for degradation, which decreases Cd uptake, thereby leading to enhanced Cd tolerance. In addition, we have also screened a transcription factor, WRKYa, which may directly regulate in transcription of ATLx gene, and found that wrkya-1 and wrkya-2 mutants are Cd sensitivity. In this project, we propose to study upstream WRKYa and downstream IRT1 of ATLx in response of plants to Cd stress, and thereby uncover a WRKYa-ATLx-IRT1 signaling pathway and its regulatory mechanism involved in cadmium accumulation and tolerance of plants.