Anthocyanin Accumulation and Related Gene Expression Profile in ‘Red Zaosu’ Pear and Its Green Mutant

Red-skinned pear is a promising commercial fruit due to its attractive appearance and nutritious value. Anthocyanin is the determinant of the red coloration of the pear peel. However, differences in anthocyanin accumulation exist among red pear cultivars with different genetic backgrounds. In this study, we analyzed the anthocyanin content and gene expression patterns in the fruits and different tissues of the red pear ‘Red Zaosu’ at different developmental stages and found a difference in anthocyanin accumulation between ‘Red Zaosu’ pear and its green mutant. The data showed that the expression profiles of transcripts that encoded critical anthocyanin biosynthetic genes were basically consistent with a tendency to a decreased anthocyanin content during fruit development, indicating that a synergistic effect of these genes was responsible for anthocyanin biosynthesis and regulation. Tissue-specific expression analysis of anthocyanin biosynthetic genes showed that they could be expressed in all tissues but at different levels. PbF3H , PbDFR , and PbANS were mainly expressed during the early flowering period, which explained the reduced levels of anthocyanin content in petals. Additionally, the content of anthocyanins and the expression levels of PbDFR , PbANS , and PbMYB10 significantly decreased in the green mutant of ‘Red Zaosu’, suggesting that PbDFR , PbANS , and PbMYB10 probably play a decisive role in determining the skin coloration of ‘Red Zaosu’ and its green mutant.