Overexpression of GhABF3 increases cotton(Gossypium hirsutum L.) tolerance to salt and drought

Plants suffer from various abiotic stresses during their lifetime, of which drought and salt stresses are two main factors limiting crop yield and quality. Previous studies have shown that abscisic acid (ABA) responsive element binding protein (AREB)/ ABRE binding factors (ABFs) in bZIP transcription factors are involved in plant stress response in an ABA-dependent manner. However, little is known about the properties and functions of AREB/ABFs, especially ABF3, in cotton.Here, we reported the cloning and characterization of GhABF3. Expression of GhABF3 was induced by drought,salt and ABA treatments. Silencing of GhABF3 sensitized cotton to drought and salt stress, which was manifested in decreased cellular antioxidant capacity and chlorophyll content. Overexpression of GhABF3 significantly improved the drought and salinity tolerance of Arabidopsis and cotton. Exogenous expression of GhABF3 resulted in longer root length and less leaf wilting under stress conditions in Arabidopsis thaliana. Overexpressing GhABF3 significantly improved salt tolerance of upland cotton by reducing the degree of cellular oxidation, and enhanced drought tolerance by decreasing leaf water loss rate. The increased expression of GhABF3 up-regulated the transcriptional abundance of downstream ABA-inducible genes under salt stress in Arabidopsis.In conclusion, our results demonstrated that GhABF3 plays an important role in plant drought and salt tolerance. Manipulation of GhABF3 by biotechnology might be an important strategy to alter the stress resistance of cotton.