Cloning, transcriptional activation, subcellular localization and expression analysis of ZjERF2 from Zoysia japonica

In this study, ZjERF2 (GenBank No. MH479420) from Zoysia japonica was cloned using the RACE method. The open reading frame of ZjERF2 was 825 bp in length, encoding 274 amino acids. One highly conserved AP2 domain was found in ZjERF2, indicating that it is a typical ERF transcription factor. Phylogenetic analysis showed that ZjERF2 has the highest genetic relationship with ERF from Panicum hallii. The pGBKT7-ZjERF2 vector was constructed and transformed into Y2HGold yeast competent cells and was found to have strong transcriptional activation activity. Using the Genome walking method, a 1 549 bp upstream promoter sequence in front of the ATG was obtained. Prediction using the PLACE online database showed that it contained multiple cis-elements that respond to hormone and stress treatments. Next, 35S꞉꞉ZjERF2꞉YFP was generated to analyse its subcellular localization character. Transient expression analysis in Nicotiana benthamiana demonstrated that ZjERF2 was located in the nucleus. To further explore its expression characteristics, real-time quantitative PCR (qRT-PCR) was performed. qRT-PCR showed that ZjERF2 was expressed in the root, stems, and leaves of Zoysia japonica. There were differences in the expression levels of ZjERF2 in varied tissues and at different developmental stages, and it was expressed most abundantly in leaves, and particularly in mature leaves. Moreover, its expression could be induced by ET and MeJA but was suppressed by NaCl, PEG, or ABA. This study indicates that ZjERF2 is a transcription factor that can participate in a variety of signal transduction pathways.