Overexpression of TaSTRG gene improves salt and drought tolerance in rice

High salt and drought are the main factors affecting agricultural production. Thus, cloning stress-tolerance-related genes and identifying their functions are essential to enhancing crop tolerance to stresses. In this study, a salt-induced unknown wheat (Triticum aestivum L.) gene was identified and cloned according to microarray analysis of salt-tolerant wheat mutant RH8706-49 under salt stress. The gene was named Triticum aestivum salt tolerance-related gene (ToSTRG) and submitted to Genbank (Accession number: EF599631). TaSTRG expression in wheat is induced by multiple stresses including salt, polyethylene glycol (PEG), abscisic acid (ABA), and cold. Transgenic rice plants overexpressing TaSTRG gene showed higher salt and drought tolerance than the control. Under salt stress, the transgenic rice had a tower intracellular Na+/K+ ratio than the control. Under salt and PEG treatments, these TaSTRG overexpressing rice plants had higher survival rate, fresh weight and chlorophyll content, accumulated higher proline and soluble sugar contents, and had significantly higher expression levels of putative proline synthetase and transporter genes than the control plants. These results indicate that the wheat TaSTRG gene could enhance plant tolerance to multiple types of stresses. (C) 2009 Elsevier GmbH. All rights reserved.