Characteristics of chalcone synthase promoters from different leaf-color malus crabapple cultivars

► In this paper, We found a 743-bp promoter fragment missing from 'ever-green-leaf' cultivar when comparing with 'ever-red-leaf' cultivar. ► The missing sequence contained all MYB transcription-factor binding site and inducing anthocyanin biosynthesis. ► The GUS staining color and the GUS activity of 12 deletion promoter fragments were different. ► Tissue expression assays in stable transgenic tobacco showed that the McCHS promoter was expressed widely.