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Article|17 May 2022|OPEN
Regulatory interaction of BcWRKY33A and BcHSFA4A promotes salt tolerance in non-heading Chinese cabbage [Brassica campestris (syn. Brassica rapa) ssp. chinensis
Huiyu Wang1 , Zhubo Li1 , Haibo Ren1 , Changwei Zhang1 , Dong Xiao1 , Ying Li1,2 and Xilin Hou1,2 , , Tongkun Liu,1 ,
1State Key Laboratory of Crop Genetics & Germplasm Enhancement, Key Laboratory of Biology and Genetic Improvement of Horticultural Crops (East China), Ministry of Agriculture and Rural Affairs of China, Engineering Research Center of Germplasm Enhancement and Utilization of Horticultural Crops, Ministry of Education of China, Nanjing Agricultural University, Nanjing 210095, China
2Nanjing Suman Plasma Engineering Research Institute, Nanjing Agricultural University, Nanjing 210095, China
*Corresponding author. E-mail: hxl@njau.edu.cn,liutk@njau.edu.cn

Horticulture Research 9,
Article number: uhac113 (2022)
doi: https://doi.org/10.1093/hr/uhac113
Views: 196

Received: 27 Jan 2022
Accepted: 27 Apr 2022
Published online: 17 May 2022

Abstract

Salinity is a universal environmental stress that causes yield reduction in plants. WRKY33, which has been extensively studied in plant defense against necrotrophic pathogens, has recently been found to be important in salt-responsive pathways. However, the underlying molecular mechanisms controlling the involvement of WRKY33 in salt tolerance have not been fully characterized. Here, we explored the function of BcWRKY33A in non-heading Chinese cabbage (NHCC). Under salt stress, BcWRKY33A expression is significantly induced in roots. As a nuclear protein, BcWRKY33A has strong transcriptional activation activity. Overexpression of BcWRKY33A confers salt tolerance in Arabidopsis, whereas silencing of BcWRKY33A causes salt sensitivity in NHCC. Furthermore, BcHSFA4A, a protein that interacts with BcWRKY33A, could directly bind to the HSE motif within the promoters of BcZAT12 and BcHSP17.6A, which are involved in the plant response to salt stress. Finally, we found that BcWRKY33A could enhance the transcriptional activity of BcHSFA4A and affect its downstream genes (e.g. BcZAT12 and BcHSP17.6A), and co-overexpression of BcWRKY33A and BcHSFA4A could promote the expression of salt-related genes, suggesting that the regulatory interaction between BcWRKY33A and BcHSFA4A improves salt tolerance in plants. Overall, our results provide insight into the molecular framework of the BcWRKY33A-BcHSFA4A signaling pathway, which also aids in our understanding of the molecular mechanism of salt tolerance in plants.