Genome-Wide Analysis of bZIP Transcription Factors and Expression Patterns in Response to Salt and Drought Stress in .

The basic leucine zipper (bZIP) transcription factors play essential roles in multiple stress responses and have been identified and functionally characterized in many plant species. However, the bZIP family members in blueberry are unclear. In this study, we identified 102 genes in . were divided into 10 groups based on phylogenetic analysis, and each group shared similar motifs, domains, and gene structures. Predictions of cis-regulatory elements in the upstream sequences of genes indicated that VcbZIP proteins are likely involved in phytohormone signaling pathways and abiotic stress responses. Analyses of RNA deep sequencing data showed that 18, 13, and 7 genes were differentially expressed in response to salt, drought, and ABA stress, respectively, for the blueberry cultivar Northland. Ten genes responded to both salt and drought stress, indicating that salt and drought have unique and overlapping signals. Of these genes, are responsive to salt, drought, and abscisic acid treatments, and their encoded proteins may integrate salt, drought, and ABA signaling. Furthermore, from group A and and from group S exhibited high or low expression under salt or drought stress and might be important regulators for improving drought or salt tolerance. Pearson correlation analyses revealed that VcbZIP transcription factors may regulate stress-responsive genes to improve drought or salt tolerance in a functionally redundant manner. Our study provides a useful reference for functional analyses of VcbZIP genes and for improving salt and drought stress tolerance in blueberry.