The WRKY transcription factors (TFs) are involved in plant responses to multiple biotic and abiotic stressors; however, the role of WRKY TFs in the regulation of Cd stress in wheat remains unknown. In this study, we investigated the mechanism of the wheat TaWRKY70 TF in Cd stress. TaWRKY70 expression in Arabidopsis was used for the functional analysis. TaWRKY70 regulated Cd tolerance with Cd accumulating in roots but not in the leaf tissues of transgenic Arabidopsis. The net Cd²⁺ influx into Arabidopsis roots decreased when TaWRKY70 was expressed. The quantitative real-time-polymerase chain reaction (qRT-PCR) results showed that the expression levels of heavy metal ATPase (AtHMA3), natural resistance-associated macrophage protein (AtNRAMP5), yellow stripe1-like (AtYSL3), and iron transport protein (AtIRT1) decreased under Cd-stress condition. Electrolyte leakage, as well as malondialdehyde and hydrogen peroxide contents, were lower in transgenic Arabidopsis than those in the wild-type (WT), whereas antioxidant enzyme activities were higher. Electrophoretic mobility shift assay (EMSA), yeast one-hybrid (Y1H) assay, and transient transactivation assay confrmed that TaWRKY70 could directly bind to the TaCAT5 promoter. Our findings provide a novel understanding of the WRKY TFs involved in the response to heavy metal stress.

WRKY 转录因子 (TFs) 参与植物对多种生物和非生物胁迫的反应；然而，WRKY TFs 在调节小麦镉胁迫中的作用仍然未知。在这项研究中，我们研究了小麦 TaWRKY70 TF 在 Cd 胁迫下的机制。拟南芥中的TaWRKY70表达用于功能分析。TaWRKY70调节 Cd 耐受性，Cd 在转基因拟南芥的根中积累，但不在叶组织中积累。当表达TaWRKY70时，流入拟南芥根的Cd ²⁺净流入减少。定量实时聚合酶链反应 (qRT-PCR) 结果表明，重金属ATP酶（AtHMA3），天然抗性相关巨噬细胞蛋白（AtNRAMP5） ，黄色stripe1状（AtYSL3），和铁转运蛋白（AtIRT1）镉胁迫条件下降低。转基因拟南芥的电解质泄漏以及丙二醛和过氧化氢含量低于野生型 (WT)，而抗氧化酶活性较高。电泳迁移率变化测定 (EMSA)、酵母单杂交 (Y1H) 测定和瞬时反式激活测定证实 TaWRKY70 可以直接与TaCAT5结合发起人。我们的研究结果提供了对参与重金属应激反应的 WRKY TF 的新理解。