Wang Huiyu, Li Zhubo, Ren Haibo, Zhang Changwei, Xiao Dong, Li Ying, Hou Xilin, Liu Tongkun
State 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.
Hortic Res. 2022 May 17;9:uhac113. doi: 10.1093/hr/uhac113. eCollection 2022.
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 in salt tolerance have not been fully characterized. Here, we explored the function of BcWRKY33A in non-heading Chinese cabbage (NHCC). Under salt stress, expression is significantly induced in roots. As a nuclear protein, BcWRKY33A has strong transcriptional activation activity. Overexpression of confers salt tolerance in , whereas silencing of causes salt sensitivity in NHCC. Furthermore, BcHSFA4A, a protein that interacts with BcWRKY33A, could directly bind to the HSE motif within the promoters of and , 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. and ), and co-overexpression of and 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.
盐度是一种普遍存在的环境胁迫因素，会导致植物产量下降。WRKY33在植物抵御坏死营养型病原体方面已得到广泛研究，最近发现它在盐响应途径中也很重要。然而，控制其参与耐盐性的潜在分子机制尚未完全明确。在此，我们探究了BcWRKY33A在不结球白菜（NHCC）中的功能。在盐胁迫下，其在根中显著诱导表达。作为一种核蛋白，BcWRKY33A具有很强的转录激活活性。过表达BcWRKY33A可使NHCC具有耐盐性，而沉默BcWRKY33A则导致NHCC对盐敏感。此外，与BcWRKY33A相互作用的蛋白BcHSFA4A可直接结合到参与植物盐胁迫响应的BcP5CS1和BcP5CR启动子内的热激元件（HSE）上。最后，我们发现BcWRKY33A可增强BcHSFA4A的转录活性并影响其下游基因（如BcP5CS1和BcP5CR），同时BcWRKY33A和BcHSFA4A共过表达可促进盐相关基因的表达，这表明BcWRKY33A与BcHSFA4A之间的调控相互作用提高了植物的耐盐性。总体而言，我们的结果为BcWRKY33A - BcHSFA4A信号通路的分子框架提供了见解，这也有助于我们理解植物耐盐性的分子机制。
