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 salt tolerance molecular mechanism in plants.

中文翻译：

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BcWRKY33A 和 BcHSFA4A 的调控相互作用促进不结球大白菜 [Brassica campestris (syn. Brassica rapa) ssp. 的耐盐性。中华]

盐度是一种普遍的环境胁迫，会导致植物减产。WRKY33 在植物防御坏死性病原体方面得到了广泛的研究，最近被发现在盐响应途径中很重要。然而，控制 WRKY33 参与耐盐性的潜在分子机制尚未完全表征。在这里，我们探讨了 BcWRKY33A 在不结球大白菜 (NHCC) 中的功能。在盐胁迫下，BcWRKY33A 在根中的表达被显着诱导。作为一种核蛋白，BcWRKY33A 具有很强的转录激活活性。BcWRKY33A 的过表达赋予拟南芥耐盐性，而 BcWRKY33A 的沉默导致 NHCC 的盐敏感性。此外，与 BcWRKY33A 相互作用的蛋白质 BcHSFA4A，可以直接与 BcZAT12 和 BcHSP17.6A 的启动子内的 HSE 基序结合，这些启动子参与植物对盐胁迫的反应。最后，我们发现 BcWRKY33A 可以增强 BcHSFA4A 的转录活性并影响其下游基因（例如 BcZAT12 和 BcHSP17.6A），并且 BcWRKY33A 和 BcHSFA4A 的共过表达可以促进盐相关基因的表达，提示调控相互作用BcWRKY33A 和 BcHSFA4A 之间的关系提高了植物的耐盐性。总体而言，我们的结果提供了对 BcWRKY33A-BcHSFA4A 信号通路分子框架的深入了解，这也有助于我们理解植物耐盐分子机制。我们发现 BcWRKY33A 可以增强 BcHSFA4A 的转录活性并影响其下游基因（例如 BcZAT12 和 BcHSP17.6A），并且 BcWRKY33A 和 BcHSFA4A 的共过表达可以促进盐相关基因的表达，表明 BcWRKY33A 之间的调控相互作用BcHSFA4A 提高植物的耐盐性。总体而言，我们的结果提供了对 BcWRKY33A-BcHSFA4A 信号通路分子框架的深入了解，这也有助于我们理解植物耐盐分子机制。我们发现 BcWRKY33A 可以增强 BcHSFA4A 的转录活性并影响其下游基因（例如 BcZAT12 和 BcHSP17.6A），并且 BcWRKY33A 和 BcHSFA4A 的共过表达可以促进盐相关基因的表达，表明 BcWRKY33A 之间的调控相互作用BcHSFA4A 提高植物的耐盐性。总体而言，我们的结果提供了对 BcWRKY33A-BcHSFA4A 信号通路分子框架的深入了解，这也有助于我们理解植物耐盐分子机制。