Characteristics of Rapeseed (Brassica rapa L.) genome DREB family demonstrate their roles in stress

Abstract

Dehydration-responsive element-binding (DREB) proteins are crucial transcription factors in plant regulatory mechanisms, playing a key role in responding to environmental stresses. Dehydration-responsive element-binding (DREB) proteins are crucial transcription factors in plant regulatory mechanisms, playing a key role in responding to environmental stresses. This study employs bioinformatics research methods to identify and characterize the DREB gene family in rapeseed (Brassica rapa L.) under abiotic stress conditions. The approach facilitates a detailed exploration of the genomic architecture and potential regulatory mechanisms that these genes may exhibit in response to environmental stresses. A whole-genome survey identified 75 DREB genes in rapeseed, which were classified into six subgroups (Ⅰ-Ⅵ) based on phylogenetic comparison with Arabidopsis homologs. The amino acid lengths of these genes ranged from 144 to 530, with predicted molecular weights between 15.63kDa and 60.36kDa, and isoelectric points from 4.48 to 9.32. Chromosomal localization revealed that these genes are distributed across 10 chromosomes, predominantly near telomeric regions, with more than 10 DREB genes located on Chr3 and Chr9 respectively. Structural domain analysis indicated that 57 DREB genes possess a single exon. Promoter cis-element analyses suggested that BrDREB genes could respond to diverse stressors, including drought, heat, hormones, and light. Transcriptomic analysis under cold stress revealed significant upregulation of BrDREB17, 24, 49, 50, and 51 in response to low temperature, while five BrDREB genes were not expressed. Specifically, BrDREB17, 24, 49, 50, and 51 showed high expression levels at 3 hours of cold stress, whereas BrDREB30, 42, and 67 were highly expressed at 24 hours of cold stress. Gene Ontology (GO) analysis demonstrated that the majority of biological processes mediated by BrDREB are associated with plant stress resistance. Protein interaction network analysis revealed that BrDREB9 and BrDREB26 interact with 15 proteins each, underscoring their significant biological roles within the DREB family in rapeseed. These findings provide a theoretical framework for further examination of the physiological and biochemical properties of the DREB gene family components in rapeseed. Our results may help to screen candidate genes for cold resistance in rapeseed and select rapeseed varieties better suited to the Tibetan locality to improve quality and yield in agricultural production.