Characterization Of The Promoter Of Key Gene (CHS) In Lili Flower Pigmentation

Flavonoids and their colored derivatives play an important role in flower pigmentation and make major contribution to a wide variety of colors, ranging from yellow to red to blue. So the regulatory mechanism of the flavonoid biosynthesis route is always one of the most intriguing problems. Large numbers of related genes have been identified and among of them, the best studied enzyme is chalcone synthase (CHS), which catalyzes the first reaction for flavonoid biosynthesisis. Previous, we isolated the 898- bp upstream region of CHS gene from Lilium orential'Sorbonne'. Here the promoter was fused toβ-glucuronidase (GUS) gene to characterize its expression pattern in Petunia hybrida'Dreams Midnight'. The chief results were showed as fo11ows:1. Characterization spatial and temporal patterns of CHS promoterGUS assay revealed GUS expression under control of the CHS promoter presented in flower but no or very weak expression was shown in the other tissues (leaf and stem). In petals, GUS activity reached the peak at developmental stages 4, and diminished at later stages. The results suggested that the CHS promoter determined a flower specific and developmentally regulated expression.2. Analysis of motifs in CHS promoterDeletion analysis displayed that even a 241- bp fragment of the promoter could still direct a flower-specific expression. The further deletion of the region from -257 to -116bp led to a week constitutive expression. Combined with the predication of cis-acting element and deletion analysis, suggested the TACPyAT box play a key role in the regulation of organ-specificity expression of the CHS promoter.3. Analysis of effects of light on CHS expressionTo further investigate the relationship between the expression pattern of CHS promoter and light, different P. hybrida organs were exposed to dark treatment, GUS expression was only detected in anther tissues. This finding indicated that light play a key role in the regulation of organ-specificity expression of the chs promoter.And the CHS expression was independently controlled between anthers and other flower tissues.