Molecular characterization of SBP-box gene family during floral induction in walnut (Juglans regia L.)

SQUAMOSA promoter-binding protein (SBP)-box genes regulate plant-specific transcription factors that play vital roles in diverse biological processes. In this study, we identified 48 SBP-box genes from Juglans regia (JrSBPs) based on the transcriptome dataset. Nineteen of these JrSBPs were predicted to be putative target genes of jre-miR156/157. Phylogenetic tree based on the conserved SBP domains divided the JrSBPs into nine groups, analogous to those from Arabidopsis. JrSBP members within the same group shared similar motifs. Cis-elements analysis implied that JrSBP genes were regulated by light, phytohormones, and stresses. Functions of JrSBP genes were predicted and analyzed by comparing the proteins of JrSBPs and SPLs from Arabidopsis. Expression profile of JrSBPs was analyzed based on RNA-seq and RT-qPCR. The results should provide fundamental information for understanding the roles of JrSBPs during floral induction.