Comprehensive genome-wide analysis of the bZIP transcription factor family reveals the potential regulator of salt stress tolerance in Brassica juncea

Mustard, one of the most important oilseed crops in India, suffers significant yield losses under salt stress. Members of the bZIP family of transcription factors (TFs) have been reported to confer tolerance to various abiotic stresses. Identification and characterization of these TFs is possible due to the availability of the genome database of mustard. Total 175 bZIP genes has been found in mustard. The phylogenetic analysis in relationships with other related genes of Arabidopsis, domain analysis, physical mapping, localization studies, gene structure analysis, investigation of conserved motifs, and examination of cis-regulatory elements for the bZIP genes were performed. The tissue-specific expression study demonstrated that four genes belonging to bZIP family had high expression in leaf tissues. Furthermore, expression of the four genes were checked by qRT-PCR under salt stress in Kranti (salt-tolerant) and NRCBH-101 (salt-susceptible) genotypes of mustard, and results showed that all four genes were differentially expressed in Kranti genotypes under salt stress. These genes may be viable candidates for additional functional validation in future as well as application in developing salt stress resilient crop. The present study altogether improves the understanding of stress adaptation in mustard by offering new genomic overview of the bZIP gene family.