Abstract

The expression of the UDP glucose: flavonoid-3-Oglucosyltransferase (UFGT), which encoded the last enzyme of the anthocyanin pathway, was under developmental control as well as affected by external stimuli such as ABA. Three fragments of the 1.38 kb upstream region of the UFGT gene from Litchi (Litchi chinesis Sonn.) were fused to the GUS-coding region, and the expression of these constructs was analyzed in onions. To characterize the cis-regulatory functions of the promoters for enzymes in anthocyanin biosynthesis, we examined onions carrying a series of nested UFGT promoter-β-glucuronidase (GUS) fusion for GUS activity by histochemical staining. The AE-box and ELI-box in anthocyanin biosynthesis of angiosperm were found in UFGT promoter. MRE which was MYB binding site involved in light responsiveness, control the transcription of genes in anthocyanin biosynthesis. The region of -910 to -344 in UFGT promoter showed high activities in the three parts. Although the expression characteristics were indistinguishable from those of the full-length promoter, we observed differences in UFGT promoter regulation for the different construct. The results suggested that region of 910 to 344 of UFGT promoter had multiple functions in the expression under the various developmental stages and stress conditions in litchi.

Key words: Flavonoid-3-Oglucosyltransferase (UFGT), promoter, litchi, transient expression.