PcRAV2 facilitates MeJA-induced anthocyanin biosynthesis by modulating PcMYB108 and PcUFGT in pear.

Abstract

Anthocyanins are important plant pigments responsible for attractive coloration and for enhancing tolerance to various abiotic stresses. Their biosynthesis is known to be regulated by methyl jasmonate (MeJA). Although the promotive effect of MeJA on anthocyanin accumulation has been widely reported, the underlying regulatory mechanisms remain insufficiently understood. In this study, we identified an ethylene-responsive factor (ERF) family transcription factor, PcRAV2, that responds to MeJA signaling and enhances anthocyanin accumulation. PcMYB10, a central gene that positively regulates anthocyanin accumulation, was indirectly activated by PcRAV2. In addition, yeast one-hybrid library screening revealed that PcMYB108 functions upstream of PcMYB10 and acts as a negative regulator of anthocyanin biosynthesis; notably, PcMYB108 expression was suppressed by PcRAV2. Furthermore, PcRAV2 directly activated PcUFGT expression by binding to its promoter. Collectively, PcRAV2 promotes anthocyanin biosynthesis through two pathways: the PcRAV2-PcMYB108-PcMYB10 transcriptional cascade and the PcRAV2-PcUFGT regulatory pathway. These findings reveal a novel MeJA-driven regulatory pathway for anthocyanin biosynthesis in plants and provide a theoretical basis for the genetic improvement of fruit coloration in pear.