Genome-Wide Organization and Expression Profiling of the SBP-Box Gene Family in Chinese Jujube (Ziziphus jujuba Mill.)

Transcription factors play vital roles in the developmental processes of plants. The SQUAMOSA promoter binding protein (SBP) genes encode a family of plant-specific transcription factors and plays many crucial roles in plant development. In this study, 16 SBP-box gene family members were identified in Ziziphus jujuba Mill. Dongzao (Dongzao), which were distributed over 8 chromosomes. They were classified into seven groups according to their phylogenetic relationships with other SBP-box gene families. Within each group, genes shared similar exon-intron structures and motif locations. The number of exons varied among the groups. We identified 12 homologous gene pairs between Dongzao and Arabidopsis. Expression profiling revealed that ZjSBP02 and ZjSBP14 expressed highly in mature fruits, ZjSBP01 expressed higher in mature leaves than other tissues and the expression level of ZjSBP12 was much higher in the flowers. The transcriptome analysis indicated that ZjSBPs had different expression patterns in various tissues. This study represents the first systematic analysis of the SBP-box gene family in Z. jujuba. The data presented here provides a foundation for understanding the crucial roles of ZjSBP genes in plant growth and development.