Transcriptional activation, subcellular localization, and expression analysis of MrERF1 from Medicago ruthenica

Ethylene responsive factors (ERFs) are widespread in plants and play a critical role in plant growth, development, and stress response. Here, based on RNA-sequence data of Medicago ruthenica under low temperature stress, we designed specific primers and cloned the MrERF1 gene by reverse transcription-polymerase chain reaction (RT-PCR). Sequence analysis showed that the MrERF1 gene contained a 948 bp open reading frame, encoding 316 amino acids. One highly conserved AP2 domain was found in MrERF1, indicating that it is a typical ERF transcription factor. Phylogenetic analysis showed that MrERF1 had the highest homology with MtABR1 in M. truncatula. A 35S꞉꞉MrERF1꞉EGFP vector was constructed. Transient expression analysis in Nicotiana benthamiana demonstrated that MrERF1 is located in the nucleus. A pGBKT7-MrERF1 vector was constructed, and its transcriptional activation activity was verified in AH109 yeast cells. Spatial expression analysis revealed that MrERF1 was expressed in the stems, leaves, buds, and inflorescences, but not in the roots. Further analysis showed that the transcription of MrERF1 was not related to photoperiod or biological rhythm. The expression of MrERF1 was induced under cold, salinity, dehydration, submergence, and abscisic acid (ABA) treatment. The present study demonstrates that MrERF1 can respond to a variety of abiotic stresses, which paves the way for further study of the functions of MrERF1.