Genome-Wide Identification and Characterization of Basic Pentacysteine Transcription Factors in Brassica napus

BARLEY B-RECOMBINANT/BASIC PENTACYSTEINE (BBR/BPC), a plant-specific transcription factor family, is a group of GAGA_motif binding factors controlling multiple developmental processes of growth and response to abiotic stresses. BPCs recruit histone remodeling factors for transcriptional repression of downstream targets. However, the information about BnaBPCs from <i>Brassica napus</i> remains unclear. Here, we identified 25 <i>BnaBPC</i> genes that were mainly localized in the nucleus, randomly localized on 16 chromosomes, and grouped into three subfamilies based on phylogenetic analysis. Twenty-five <i>BnaBPC</i> genes exhibit syntenic relationships with <i>AtBPC</i> genes, and the polypeptides encoded by <i>BnaBPC</i> genes within the same subfamily share similar conserved motifs and protein domains. The expansion of <i>BnaBPC</i> genes underwent whole-genome duplication events and purifying selection in genomes, and all the <i>BnaBPC</i> genes had the same conserved GAGA binding domains. Additionally, the promoter of each <i>BnaBPC</i> gene consisted of various <i>cis</i>-elements associated with stresses, phytohormones, and growth and development. Notably, the seed-specific regulatory element was found only in the <i>BnaC04.BPC4</i> promoter. Further expression pattern analysis showed that <i>BnaBPC</i> members are widely expressed in stems, buds, developing seeds and siliques. These findings provide insights into <i>BnaBPC</i> genes and enrich our understanding of their functional characterization in <i>B. napus</i>.