Abstract:Based on the red-flesh color peaches showing different intensities, this study attempted to decipher their formation mechanism in order to provide theoretical basis for efficient breeding of red peach varieties. The promoter activity of PpMYB10.1 was detected via GUS staining, and the candidate transcription repressors binding on its promoter were captured through DNA-pull down assay. The function of these candidate genes were determined by double luciferase and yeast two-hybrid assay. The results showed that: (1) The expression of PpMYB10.1 and anthocyanin content in flesh peaches with deep-red, red and light-red were gradually decreasing. (2) Activity of PpMYB10.1 promoter with a 483 bp deletion was weaker than that without the sequence. (3) Interestingly, we identified a candidate transcription repressor Prupe.2G302800 based on the 483bp deletion. The protein strongly interacted with PpBL, a major factor in anthocyanin synthesis and resulted in a reduction on the transcription of PpMYB10.1. Prupe.2G302800 is unlikely the direct factor modulating the red flesh of peach, whereas it might play an important role in decreasing red-flesh color by inhabiting PpBL transcription activity.