Heterologous Expression of Dehydration-Inducible of Confers Drought and Salt Tolerance in .

As the only woody resurrection plant, Myrothamnus flabellifolia has a strong tolerance to drought and can survive long-term in a desiccated environment. However, the molecular mechanisms related to the stress tolerance of are largely unknown, and few tolerance-related genes previously identified had been functionally characterized. WRKYs are a group of unique and complex plant transcription factors, and have reported functions in diverse biological processes, especially in the regulation of abiotic stress tolerances, in various species. However, little is known about their roles in response to abiotic stresses in M. flabellifolia. In this study, we characterized a dehydration-inducible transcription factor gene, , from M. flabellifolia. shows high degree of homology with genes from and belonging to group II of the WRKY family. Unlike known WRKY17s in other organisms acting as negative regulators in biotic or abiotic stress responses, overexpression of in significantly increased drought and salt tolerance. Further investigations indicated that participated in increasing water retention, maintaining chlorophyll content, and regulating ABA biosynthesis and stress-related gene expression. These results suggest that MfWRKY17 possibly acts as a positive regulator of stress tolerance in the resurrection plant