ThHSFA1 Confers Salt Stress Tolerance through Modulation of Reactive Oxygen Species Scavenging by Directly Regulating ThWRKY4

• Published in: International journal of molecular sciences 2021-05, Vol.22 (9), p.5048
• Main Authors: Sun, Ting-Ting, Wang, Chao, Liu, Rui, Zhang, Yu, Wang, Yu-Cheng, Wang, Liu-Qiang
• Format: Article
• Language: English
• Subjects: Abiotic stress; Abscisic acid; antioxidant enzyme; Antioxidants; C-Terminus; Chromatin; Cloning; Environmental impact; Enzymatic activity; Enzyme activity; Enzymes; Gene expression; Heat shock; heat shock element; heat shock transcription factor; Homeostasis; Immunoprecipitation; Localization; Physiology; Proteins; Reactive oxygen species; ROS; Salinity; Salinity tolerance; salt stress; Scavenging; Tamarix hispida; Tobacco; Transcription factors; Transgenic plants; Yeast
• ISSN: 1422-0067; 1661-6596; 1422-0067
• DOI: 10.3390/ijms22095048

Heat shock transcription factors (HSFs) play critical roles in several types of environmental stresses. However, the detailed regulatory mechanisms in response to salt stress are still largely unknown. In this study, we examined the salt-induced transcriptional responses of ThHSFA1-ThWRKY4 in Tamarix hispida and their functions and regulatory mechanisms in salt tolerance. ThHSFA1 protein acts as an upstream regulator that can directly activate ThWRKY4 expression by binding to the heat shock element (HSE) of the ThWRKY4 promoter using yeast one-hybrid (Y1H), chromatin immunoprecipitation (ChIP), and dual-luciferase reporter assays. ThHSFA1 and ThWRKY4 expression was significantly induced by salt stress and abscisic acid (ABA) treatment in the roots and leaves of T. hispida. ThHSFA1 is a nuclear-localized protein with transactivation activity at the C-terminus. Compared to nontransgenic plants, transgenic plants overexpressing ThHSFA1 displayed enhanced salt tolerance and exhibited reduced reactive oxygen species (ROS) levels and increased antioxidant enzyme activity levels under salt stress. Therefore, we further concluded that ThHSFA1 mediated the regulation of ThWRKY4 in response to salt stress in T. hispida.