Chang Xiaoyao, Zhang Xiaoyan, Huang Xiumei, Zhang Fenglan, Yang Zhongren
Inner Mongolia Key Laboratory of Wild Peculiar Vegetable Germplasm Resource and Germplasm Enhancement, College of Horticultural and Plant Protection, Inner Mongolia Agricultural University, Inner Mongolia, Huhhot, China.
Department of Horticulture and Landscape Technology, Inner Mongolia Agricultural University Vocational and Technical College, Inner Mongolia, Baotou City, China.
J Plant Physiol. 2025 Sep;312:154575. doi: 10.1016/j.jplph.2025.154575. Epub 2025 Jul 26.
The WRKY transcription factor CtWRKY70 from Cynanchum thesioides was functionally characterized to explore its role in abiotic stress responses. CtWRKY70, encoding a 340-amino acid protein from the WRKY Group III subfamily, localizes to the nucleus and exhibits transcriptional activation activity. Its expression is significantly induced by salt and drought stress. Overexpression of CtWRKY70 in Arabidopsis improved tolerance to both stresses, as evidenced by enhanced survival rates, maintained biomass, and preserved chlorophyll content. Transgenic lines exhibited elevated antioxidant enzyme activities (SOD, CAT, POD) and increased proline accumulation, with CtWRKY70 directly bound to the promoter of the AtSOD1 gene as confirmed by electrophoretic mobility shift assay (EMSA) and yeast one-hybrid (Y1H) assays, indicating enhanced ROS scavenging and osmoregulation. In contrast, CtWRKY70-silenced plants showed heightened stress sensitivity, characterized by greater wilting, increased stomatal aperture, and accelerated water loss. Y2H and BiFC assays confirmed the interaction of CtWRKY70 with another stress-responsive WRKY protein, CtWRKY41. These results demonstrate that CtWRKY70 positively regulates drought and salt tolerance by coordinating antioxidant defense and osmotic adjustment. This study provides valuable insights into the molecular mechanisms of WRKY-mediated stress adaptation in horticultural species, positioning CtWRKY70 as a potential genetic target for improving crop resilience.
为了探究其在非生物胁迫响应中的作用，对来自白首乌的WRKY转录因子CtWRKY70进行了功能鉴定。CtWRKY70编码一个来自WRKY III亚家族的340个氨基酸的蛋白质，定位于细胞核并具有转录激活活性。其表达受到盐和干旱胁迫的显著诱导。在拟南芥中过表达CtWRKY70提高了对这两种胁迫的耐受性，表现为存活率提高、生物量维持和叶绿素含量保持。转基因株系表现出抗氧化酶活性（超氧化物歧化酶、过氧化氢酶、过氧化物酶）升高和脯氨酸积累增加，电泳迁移率变动分析（EMSA）和酵母单杂交（Y1H）分析证实CtWRKY70直接与AtSOD1基因的启动子结合，表明活性氧清除和渗透调节增强。相比之下，CtWRKY70沉默的植株表现出更高的胁迫敏感性，其特征为更严重的萎蔫、气孔孔径增大和水分流失加速。酵母双杂交（Y2H）和双分子荧光互补（BiFC）分析证实CtWRKY70与另一个胁迫响应性WRKY蛋白CtWRKY41相互作用。这些结果表明，CtWRKY70通过协调抗氧化防御和渗透调节来正向调节干旱和盐耐受性。本研究为园艺物种中WRKY介导的胁迫适应分子机制提供了有价值的见解，将CtWRKY70定位为提高作物抗逆性的潜在遗传靶点。
