MdNAC72-like regulation of anthocyanin and proanthocyanidin synthesis in apple

Flavonoid compounds, including anthocyanins and proanthocyanidins, are significant secondary metabolites in plants and play crucial roles in various aspects of plant growth, development, and environmental stress responses. In the present study, we identified a key transcription factor from the NAC family, designated as MdNAC72-like, which had a strong correlation with the anthocyanin content during the apple fruit ripening process. Through techniques including yeast one-hybrid analysis, electrophoretic mobility shift assays, and luciferase reporter assays, we illustrated that MdNAC72-like directly interacts with the promoters of the MdMYB9 , MdLAR , and MdUFGT genes. This interaction enhances their transcriptional activity, leading to a favorable impact on the biosynthesis of anthocyanins and proanthocyanidins in plants. Furthermore, utilizing yeast two-hybrid, pull-down, and bimolecular fluorescence complementation assays, we demonstrated that MdERF1B forms an interaction with MdNAC72-like, which in turn augments the transcriptional activation ability of MdNAC72-like on the downstream structural genes MdMYB9 , MdLAR , and MdUFGT . In conclusion, MdNAC72-like presents significant research potential, and these results offer a theoretical framework for understanding the regulatory mechanisms governing anthocyanin and proanthocyanidin synthesis in apple.