Visible light induces the PpHYH transcription to promote anthocyanin pigmentation in peach peel

Light is important for fruit coloration, but molecular mechanisms underlying the impact of visible light on anthocyanin pigmentation in peach peel remain elusive. Here, we investigated the influence of visible light, including red, green and blue light, on peel coloration in peach. Blue light had a better ability to induce anthocyanin pigmentation in peach peel than red and green light. A transcription factor, PpHYH , was identified to be responsible for visible light-induced anthocyanin accumulation in peach peel. The PpHYH gene was more highly expressed in peach peel exposed to blue light than in the peel exposed to red and green light. Moreover, PpHYH had two alternative splicing variants, PpHYH-X1 and PpHYH-X2 , with the latter having a stronger ability to activate transcription of PpMYB10.1 . Blue light had better ability to increase the ratio of PpHYH-X2 to PpHYH-X1 compared to green and red light. Thus, the role of blue light in peach peel anthocyanin pigmentation could be attributed to its ability to activate the transcription of PpHYH and to ensure the relative abundance of the PpHYH-X2 transcript. Additionally, light was able to enhance the occurrence of alternative splicing variants in peach peel. Our results confirmed the important role of PpHYH gene in light-induced anthocyanin pigmentation in peach peel.