Genome-Wide Identification and Functional Analysis of the PEBP Gene Family in Begonia semperflorens ‘Super Olympia’ Reveal Its Potential Role in Regulating Flowering

The phosphatidylethanolamine-binding protein (PEBP) gene family, known for its pivotal role in controlling floral transition, regulates flowering time, and, thus, shapes the continuous-flowering trait in ornamental plants. In this study, we conducted the first genome-wide identification and bioinformatics analysis of the <i>PEBP</i> gene family in <i>Begonia semperflorens</i> 'Super Olympia', a variety that exhibits year-round flowering. Via phylogenetic analysis, a total of 10 <i>BsPEBP</i> genes were identified and categorized into four subfamilies: the FT-like (two members), TFL1-like (three members), PEBP-like (three members), and MFT-like (two members) subfamilies. Gene structure analysis revealed highly conserved motif compositions among family members, and protein tertiary structure prediction indicated the dominance of random coils in their structures. Promoter cis-acting element analysis revealed light-responsive, hormone-responsive (ABA, GA, and JA), and abiotic stress-responsive elements in the <i>BsPEBP</i> genes, suggesting their potential integration into multiple regulatory pathways. The tissue-specific expression profiles revealed that <i>BsPEBP6</i> was significantly upregulated in floral organs, whereas TFL1-like subfamily members were predominantly expressed in vegetative tissues. These findings imply that the <i>FT-like</i> and <i>TFL1-like</i> genes antagonistically regulate the continuous-flowering trait of <i>B. semperflorens</i> 'Super Olympia' through their respective roles in promoting and repressing flowering. Our findings provide a preliminary theoretical foundation for elucidating the molecular mechanisms by which the <i>PEBP</i> gene family regulates flowering time in ornamental plants and offer valuable insights for developing breeding strategies aimed at flowering time modulation.