Evolutionary and expression analyses of the DREB family in Scutellaria baicalensis and functional characterization of SbDREB10 in response to salt stress

Soil salinization poses a major threat to the sustainability of agriculture worldwide, necessitating the exploration of salt tolerance mechanisms and key genetic resources for breeding. As key components of the AP2/ERF family, DREB transcription factors (TFs) are essential for plant stress tolerance, primarily by binding to CRT/DRE promoter elements. In this study, we performed a comprehensive analysis of the DREB family in S. baicalensis , identifying 49 SbDREB genes. Phylogenetic analysis categorized them into six subgroups, with subgroup A2 showing significant correlations with salt stress. Expression profiling revealed that SbDREB10 was significantly induced under salt, drought and hormone treatments. Functional analysis showed that SbDREB10 is a nuclear protein with transcriptional activation activity. The overexpression of SbDREB10 could significantly enhance salt tolerance, in part by increasing antioxidant enzyme activities and reducing ROS levels, while SbDREB10-silenced S. baicalensis plants displayed increased salt sensitivity. Furthermore, SbDREB10 positively regulates the transcriptional levels of stress-related genes like APX2 and DREB2A and directly activates SbSOD2 expression by binding to its promoter. This study delivers the first in-depth evolutionary and functional characterization of DREB family in S. baicalensis , suggesting that SbDREB10 exerts a positive role in salt stress response and can serve as a candidate gene for breeding stress-resistant medicinal plants.