Genome-Wide Identification and Characterization of the SBP Gene Family in Passion Fruit ( Passiflora edulis Sims).

The SQUAMOSA promoter binding proteins (SBPs) gene family plays important roles in plant growth and development. The gene family has been identified and reported in many species, but it has not been well studied in passion fruit. In this study, a total of 14 genes were identified in passion fruit and named from to based on their chromosomal distribution. The phylogenetic tree, gene structure, conserved motifs, collinearity analysis, and expression patterns of the identified SBP members were analyzed. We classified the genes into eight groups (I to VIII) according to the phylogenetic tree, gene structure, and conserved motifs. Synteny analysis found that 5 homologous gene pairs existed in genes and 11 orthologous gene pairs existed between passion fruit and Arabidopsis. Synonymous nucleotide substitution analysis showed that the genes were under strong negative selection. The expression pattern of genes in seed, root, leaf, and flower showed that nine of the PeSBP genes displayed high expression in the leaf and the flower. The expression patterns of //// were further detected by qRT-PCR. In addition, differences in the expression levels occurred for each gene in the different flower organs and at the different developmental stages. There were large differences among based on transcriptional levels under cold, heat, salt, and osmotic stress conditions. Altogether, this study provides an overview of genes in passion fruit and lays the foundation for further functional analysis.