Cloning and characteristics of flavonol synthase promoter from Malus crabapple

A 1.8-kb 5RSQUO-upstream sequence of flavonol synthase (McFLS) from LSQUOever-red-leafRSQUO color types of Malus crabapple cultivar LSQUORoyaltyRSQUO was isolated. The PLACE database (a database of motifs found in plant cis-acting regulatory DNA elements) analysis showed that there were numerous functional elements in the McFLS promoter. Many light-responsive elements that indicated the expression of McFLS had a close relationship with light induction was discovered. Abundant auxin and gibberellic acid (GA) responsive elements suggested that McFLS mainly expressed in the early development stage. Many stress-responsive elements were consistent with the functional characteristics of flavonols in induction and stress-resistance reactions. The expression level analysis verificated the role of cis-element in McFLS promoter. To conclude, the McFLS promoter has potential research significance to explore the function of McFLS.