CdWRKY2 transcription factor modulates salt oversensitivity in bermudagrass [ (L.) Pers.].

Common bermudagrass [ (L.) Pers.] has higher utilization potential on saline soil due to its high yield potential and excellent stress tolerance. However, key functional genes have not been well studied partly due to its hard transformation. Here, bermudagrass "Wrangler" successfully overexpressing exhibited significantly enhanced salt and ABA sensitivity with severe inhibition of shoot and root growth compared to the transgenic negative line. The reduced auxin accumulation and higher ABA sensitivity of the lateral roots (LR) under salt stress were observed in overexpression lines. IAA application could rescue or partially rescue the salt hypersensitivity of root growth inhibition in -overexpressing and bermudagrass, respectively. Subsequent experiments in indicated that CdWRKY2 could directly bind to the promoter region of and downregulated its expression to further upregulate the expression of ABA and auxin pathway-related genes. Moreover, overexpression in background could partly rescue the salt-inhibited LR growth caused by overexpression These results indicated that CdWRKY2 could negatively regulate LR growth under salt stress the regulation of ABA signaling and auxin homeostasis, which partly rely on AtMAPK3 function. CdWRKY2 and its homologue genes could also be useful targets for genetic engineering of salinity-tolerance plants.