Genome-Wide Characterization and Expression of the bZIP Family in Black Raspberry

Basic leucine zipper (bZIP) transcription factor family members play important roles in many aspects of anthocyanin accumulation and adaptation to the environment. However, little information is available about the bZIP genes in black raspberry. Herein, 49 RobZIP genes were identified and renamed based on their respective chromosome distribution (including five that could not be located to chromosomes). According to phylogenetic analysis, RobZIPs are divided into 13 subfamilies. RobZIPs have 1-19 exons, 137-890 amino acids, and theoretical PIs of 4.79-10.3. Moreover, most RobZIP genes are located in the nucleus. The analysis of cis-acting elements in the promoters of these genes showed that there were many elements related to light, hormones and abiotic stress. Through abscisic acid (ABA) treatment, we found that most RobZIP genes in black raspberry fruits or leaves were significantly expressed, but the trends in the responses to ABA differed. In addition, there were differences in the expression levels of RobZIP genes in different tissues and fruit developmental stages of black raspberry, which suggest possible different functions of RobZIP members. This study identified and analyzed the bZIP family genes in black raspberry to provide a basis for further functional verification of bZIP genes.