Apple MdMYB306‐like inhibits anthocyanin synthesis by directly interacting with MdMYB17 and MdbHLH33

SUMMARY Anthocyanin is one of the most important pigments and nutrients in fruits. Genes encoding R2R3‐MYB transcription factors (TFs) are key to anthocyanin regulation. R2R3‐MYB activators have been widely studied in the anthocyanin synthesis pathway. However, the mechanism by which R2R3‐MYB repressors negatively regulate anthocyanin synthesis remains poorly understood. In the present study, we characterized a subfamily 1 R2R3‐MYB anthocyanin repressor gene, MYB306‐like , from apple ( Malus × domestica ) and demonstrated its significance in anthocyanin regulation. The MdMYB306‐like protein activates the expression of an anthocyanin repressor gene, MdMYB17 , and inhibits the expression of MdDFR (an anthocyanin structural gene) by directly binding to the corresponding promoters. The MdMYB306‐like protein interacts with MdMYB17 and MdbHLH33 through its N‐terminus. In addition, MdMYB306‐like interacts with MdbHLH33 and MdMYB17 to enhance its regulatory activities on MdMYB17 and MdDFR , respectively. Our results revealed that the MdMYB306‐like protein, in conjunction with MdMYB17 and MdbHLH33, forms a key regulatory module to fine‐tune anthocyanin synthesis in apple.