Cloning the promoter of the sucrose transporter gene PsSUT2 and screening its upstream transcription factors in tree peony

Abstract

Sucrose is an essential energy substance for tree peony (Paeonia Suffruticosa) floral organ development. However, little is known about the sucrose regulatory network in tree peony. In this study, the promoter sequence of the tree peony sucrose transporter gene PsSUT2 was cloned. Through cis-acting elements analysis and weighted gene co-expression network analysis (WGCNA), 6 transcription factors potentially regulating PsSUT2 were screened. Expression analysis revealed that the 6 transcription factors had similar expression trends with the PsSUT2 in all parts of peony at the full bloom stage. Furthermore, a yeast one-hybrid assay revealed that PsMYB20 and PsMADS9 bind to the PsSUT2 promoter. Dual-luciferase reporter assay demonstrated that PsMYB20 and PsMADS9 could activate PsSUT2 expression. Taken together, our findings suggest that PsMYB20 and PsMADS9 positively regulate PsSUT2, laying the foundation for the construction of a gene network for sucrose regulation in tree peony.