Genome-Wide Identification and Characterization of bZIP Transcription Factors inBrassica oleraceaunder Cold Stress
Cabbages (Brassica oleraceaL.) are an important vegetable crop around world, and cold temperature is among the most significant abiotic stresses causing agricultural losses, especially in cabbage crops. Plant bZIP transcription factors play diverse roles in biotic/abiotic stress responses. In this study, 119 putative BolbZIP transcription factors were identified using amino acid sequences from several bZIP domain consensus sequences. The BolbZIP members were classified into 63 categories based on amino acid sequence similarity and were also compared with BrbZIP and AtbZIP transcription factors. Based on this BolbZIP identification and classification, cold stress-responsiveBolbZIPgenes were screened in inbred lines,BN106andBN107, using RNA sequencing data and qRT-PCR. The expression level of the 3 genes,Bol008071,Bol033132, andBol042729, was significantly increased inBN107under cold conditions and was unchanged inBN106. The upregulation of these genes inBN107, a cold-susceptible inbred line, suggests that they might be significant components in the cold response. Among three identified genes,Bol033132has 97% sequence similarity toBra020735, which was identified in a screen for cold-related genes inB. rapaand a protein containing N-rich regions in LCRs. The results obtained in this study provide valuable information for understanding the potential function of BolbZIP transcription factors in cold stress responses.