Abstract

WRKY transcription factors play important roles in abiotic stress by directly regulating stress-related genes. However, the molecular mechanism of its involvement in salt stress in pak-choi is still poorly understood. In this study, we elucidated the function of BcWRKY1 from pak-choi ( Brassica rapa ssp. chinensis ) in salt stress. The expression level of BcWRKY1 showed the highest in rosette leaves among different tissues and was induced by salt and ABA treatment in pak-choi. Subcellular localization showed that BcWRKY1 was located in nucleus. The transgenic Arabidopsis overexpressing BcWRKY1 exhibited enhanced salt sensitivity and higher H 2 O 2 contents, which were further confirmed by silencing BcWRKY1 in pak-choi. In addition, the expression of ZAT12 was negatively regulated with BcWRKY1 under salt stress both in pak-choi and Arabidopsis . Yeast one-hybrid and dual luciferase reporter assay showed that BcWRKY1 could bind to the promoter of BcZAT12 , and BcsAPX expression was activated by BcZAT12. To sum up, we propose a BcWRKY1–BcZAT12–BcsAPX regulatory model that involves in pak-choi salt stress response.