The intron from the 5′-UTR of the FBP11 gene in petunia displays promoter- and enhancer-like functions

Evidence now exists that introns have many important biological functions in various aspects, including regulation and structural purposes, facilitating genetic diversification, molecular evolution and so on. In this study, the β-glucuronidase (GUS) gene was separately placed downstream of the FBP11 promoter (PF11) and the intron from the 5′-UTR (F11I); histochemical staining showed that both the PF11 and F11I have the capacity to activate the expression of the GUS gene. Moreover, when the F11I was placed between the Cauliflower Mosaic Virus (CaMV) 35S promoter and GUS gene, the expression level of the GUS in the transgenic tobacco plants was three to nine fold increases than the CaMV 35S promoter alone. These observations indicate that the intron from the 5′-untranslated region (5′-UTR) of Floral Binding Protein 11 (FBP11) gene in petunia (Petunia hybrida) displays both promoter- and enhancer-like functions.

► The intron in the 5′-UTR of FBP11 possesses promoter- and enhancer-like functions. ► Co-existence of both the promoter and the intron constrain a higher specificity of gene expression. ► The F11I acts as a positive determinant when fused with the FBP11 promoter region.