Expression analysis and subcellular localization of an ERF transcription factor from Salvia miltiorrhiza

Abstract

A SmERF1 gene was isolated from Salvia miltiorrhiza, and expression patterns to different stress condition were analysed in the root tissues of S. miltiorrhiza. The cDNA of SmERF1 gene from S. miltiorrhiza was isolated by RTPCR, and the phylogenetic tree using the neighbour-joining tree method in Mega 5 was obtained. To confirm the protein is likely to localize in the nucleus, the SmERF1 coding region was fused to the N-terminus of the GFP gene under the control of the CaMV 35S promoter and transferred into onion epidermal cells using the particle bombardment method. Semi-quantitative RT-PCR analysis revealed different expression pattern of SmERF1 gene in response to exogenous ABA, MeJA and SA. The phylogenetic tree analysis revealed that SmERF1 is most similar to AP2/ERF VII subgroup members. The transient expression of the SmERF1::GFP fusion protein indicated that the SmERF1 was exclusively localized to the nucleus. The transcript of SmERF1 highly accumulated when the plants were treated with MeJA, while accumulated slightly in response to exogenous ABA, salicylic acid. These results suggest hormone such as ABA, MeJA and SA signaling pathways can be involved in the activation and inhibition of the SmERF1.