Identification and comparison of SQUAMOSA promoter-binding protein in different Osmanthus fragrans Lour. varieties

The SQUAMOSA promoter-binding protein (SBP/SPL) family represents a group of plant-specific transcription factors involved in diverse biological processes. In this study, genomic data were used to identify and analyze SBP gene family members across four varieties of Osmanthus fragrans Lour. A total of 172 SBP genes were identified, with each variety exhibiting distinct numbers of genes and unique chromosomal distributions. Phylogenetic analysis classified these genes into nine subfamilies, with variations in the subfamily distribution across the four varieties. Members within the same subfamily shared similar gene modules and structures, all containing the conserved domains characteristic of SBP genes. Promoter analysis revealed that the cis-acting elements of SBP genes were associated with plant hormones, growth and development, defense, and stress. Tissue-specific analysis demonstrated that most SBP genes were expressed in the stems, leaves, and flowers, suggesting functional involvement in these tissues.