Genome-wide identification and analysis of bZIP gene family reveal their roles under salt stress in Suaeda australis

Abstract

Background Suaeda australis is one of typical halophyte owing to high levels of salt tolerance. In addition, the bZIP gene family assumes pivotal functions in response to salt stress. However, there are little reports available regarding the bZIP gene family in S. australis. Results In this study, we successfully screened 44 bZIP genes within S. australis genome. Subsequently, we conducted an extensive analysis, encompassing investigations into chromosome location, gene structure, phylogenetic relationship, promoter region, conserved motif, and gene expression profile. The 44 bZIP genes categorized into 12 distinct groups, exhibiting an uneven distribution among the 9 chromosomes of S. australis chromosomes, but one member (Sau23745) was mapped on unanchored scaffolds. Examination of cis-regulatory elements reveled that bZIP promoters were closely related to anaerobic induction, transcription start, and light responsiveness. Expression patterns analyses clearly discovered the role of several SabZIPs including Sau08107, Sau08911, Sau11415, Sau16575, and Sau19276, which showed higher expression levels in higher salt concentration than low concentration and obviously response to salt stress. These expression patterns were corroborated through RT-qPCR analysis. Conclusions Our findings offer valuable insights into the evolutionary trajectory of the bZIP gene family in S. australis and shed light on their roles in responding to salt stress. In addition to fundamental genomic information, these results would serve as a foundational framework for future investigations delving into the regulation of salt stress responses in S. australis.