Characterization of OfRGA in regulation of flower size and colour through tuning cell expansion genes.

Through RNA-seq analysis, a total of 1911 up-regulated differentially expressed genes (DEGs) and 1646 down-regulated DEGs were identified. Subsequent investigation revealed a significant down-regulation of genes associated with cell wall synthesis and expansion, such as CesA1, XEH, and EXPB1, as well as genes related to anthocyanin synthesis. Overall, our findings suggest that OfRGA modulates tobacco petal size by influencing cell expansion. This study provides a foundational understanding of the role of DELLA protein in the development of Osmanthus flower organs.