Overexpression of peach NAC25 promotes anthocyanin biosynthesis in poplar shoots

Anthocyanins, a categories of metabolites derived from flavonoid biosynthesis pathway, are responsible for the red color of peach. Anthocyanin metabolism is modulated by a complicated regulatory network. In this study, our results demonstrated that PpNAC25 was a component of anthocyanin regulatory network in peach. PpNAC25 showed a closed relationship with the well-known ripening-related gene NOR (no-ripening) and was highly expressed in peach fruit. Overexpression of PpNAC25 in poplar resulted in a redder shoot tips compared with EV control. PpNAC25 overexpression upregulated the anthocyanin biosynthetic and transportation genes in transcript levels and then increased anthocyanin contents. In Y1H and Luc/Ren assay, PpNAC25 bound to the promoter of the anthocyanin-activator PpMYB10.1 and PpMYB10.2 and activated its transcript. Moreover, PpNAC25 formed a heterodimer with PpNAC1, an anthocyanin-regulator. Our researches provide evidence that PpNAC25 may be a positive regulator of anthocyanin biosynthesis in peach fruit.