Identification and analysis of transcription factor encoding CBF1/ DREB1B gene in Viola tricolor L

Abstract Transcription factors belonging to the CBF/ DREB1 (C-repeat binding factor/ Dehydration-Responsive Element Binding Protein B) gene family along with 3 other independent regulatory systems in plants (MYB, MYC and bZIP) play a significant role in activation of genes responding to environmental stresses including cold, heat, salinity and drought. In this study, in order to identify one of the genes of CBF family called CBF1 / DREB1B in the genome of Viola tricolor L., plants were subjected to temperature treatment at 4°C for 2 hours. Total RNA was extracted from viola leaves and used for cDNA synthesis. The presence of the gene in the V. tricolor genome was confirmed via PCR on cDNA, followed by sequencing of the resulting PCR fragments. The 573-nucleotide sequence identified, considering the significant conservation reported in the gene and protein sequence of the CBF gene family, as expected, revealed a high degree of sequence homology and conservation to the CBFs identified in taxonomically close and even far species with V. tricolor. The structure and phylogenetic status of the V. tricolor CBF1 was analyzed based on the identified region and the evolutionarily closest plant species were determined according to the nucleotide and protein sequence of this gene.