The main cis-acting elements in MdGST promoters and expression patterns of MdGST genes during fruit development. (A) Promoter analysis was performed on 2000-bp sequences upstream of the transcription start sites. (B) KID-S1 (85 days after flowering), KID-S2 (107 days after flowering), KID-S3 (128 days after flowering), and KID-S4 (145 days after flowering) represent the four main stages of anthocyanin accumulation during fruit developmental stages, KID represents the ‘Gala’ strain. The color in the Figure 3B indicates the expression level, which is the normalized value of pHeatmap in R language of Log 2 FC. The deeper the red is, the higher the expression is. The deeper the green is, the lower the expression is.