Overexpression of MbERF12, an ERF gene from Malus baccata (L.) Borkh, increases cold and salt tolerance in Arabidopsis thaliana associated with ROS scavenging through ethylene signal transduction

Abiotic stress, such as drought, salt, and cold, affects normal plant growth. Ethylene response factors (ERFs) play an important role in the responses of plants to different stresses. An ERF gene was cloned from Malus baccata (L.) Borkh and named as MbERF12. A subcellular localization study proved that MbERF12 was a nucleus-localized protein. The expression level of MbERF12 was higher in stems and roots, which was markedly affected by high salinity, low temperature, and ethephon treatments. When MbERF12 was transformed into Arabidopsis thaliana, it obviously improved salt and low-temperature tolerance in transformed plants. Overexpression of MbERF12 in transformed A. thaliana also led to higher levels of peroxidase (POD), catalase (CAT), and superoxide dismutase (SOD) and higher contents of ethylene, chlorophyll, and proline, while the content of malondialdehyde (MDA) was lower, especially when being dealt with low-temperature and high-salinity stresses. MbERF12 plays a key role in the response to salt and cold stresses in Arabidopsis by improving the scavenging ability for reactive oxygen species (ROS) through ethylene signal transduction. We proposed that MbERF12 may function as a positive regulator for abiotic stress responses and can be considered as a potential gene for improvement of cold and high-salinity tolerance in plants.