Isolation and characterization of GoDREB encoding an ERF-type protein in forage legume Galegae orientalis

ERF is a unique transcription factor in higher plants with AP2-like DNA-binding domains. An ERF-like gene was isolated from Galegae orientalis, termed GoDREB. Sequence alignment showed that it shares high identity with other ERF family members in AP2 domain. Transient expression analysis indicated that GoDREB protein is localized in the nucleus. Quantitative RT-PCR analysis results showed that GoDREB is induced by a variety of abiotic stress, such as cold, dehydration, and high-salinity. Exogenous hormones, such as methyl jasmonate acid and salicylic acid, also up-regulate the expression of GoDREB. However, ABA did not induce the mRNA accumulation of GoDREB. These results implied that the GoDREB might play a role in these two hormones-dependent but not be involved in the ABA-dependent stress signaling pathway. Overexpression of GoDREB in transgenic tobacco plants resulted in higher tolerance to high salinity, osmotic and low-temperature stresses. These results suggest that GoDREB may play an essential role as an ERF transcription factor in regulation of stress-responsive signaling in G. orientalis.