A member of wheat class III peroxidase gene family, named TaPRX-2A, enhanced the tolerance of salt stress

Background: Abiotic stresses including salt stress are environment stresses of limiting the crop growth and yield. It was reported that peroxidases (PRX) were involved in various abiotic stress responses. However, few wheat PRXs were characterized in the mechanism of abiotic stresses. Results: In this study, a novel wheat PRX gene named TaPRX-2A, a member of wheat class III peroxidase gene family, was cloned and characterized in salt stress response. According to the identification of class III PRXs in 12 different plants, we proposed an evolutionary model that this TaPRX-2A may have experienced some exon fusion events during evolution. The results of expression pattern showed that TaPRX-2A exhibited relatively high expression levels in root tissue, but low in stem and leaf tissues by using qRT-PCR. This TaPRX-2A was also induced by some stress and hormone treatments including PEG6000, NaCl, H 2 O 2 , SA, JA, and ABA. The result of overexpressing transgenic wheat showed that this TaPRX-2A enhanced the tolerance of salt comparing the wild-type wheat (WT). We also studied the molecular mechanism of TaPRX-2A mediating the salt stress response. Physiological experiments indicated that TaPRX-2A -overexpressing transgenic wheat possessed a higher survival rate, higher relative water content, and longer shoot length than WT, but remained the same in the root length under salt stress. Further experiments indicated that TaPRX-2A -overexpressing transgenic lines enhanced abiotic tolerance by enhancing oxidative stress tolerance, such as higher antioxidant activities of superoxide dismutase (SOD), peroxidase (POD) and catalase (CAT) enzymes, reduction of reactive oxygen species (ROS) accumulation, and lower levels of MDA content. Moreover, the transcript levels of stress-related genes were up-regulated by overexpression of TaPRX-2A. Conclusions: The results showed that TaPRX-2A play a positive factor in response to salt stress by scavenging ROS and regulating stress-related genes.