Whole-Genome DNA Methylation Associated With Differentially Expressed Genes Regulated Anthocyanin Biosynthesis Within Flower Color Chimera of Ornamental Tree Prunus mume

DNA methylation is one of the best-studied epigenetic modifications involved in many biological processes. However, little is known about the epigenetic mechanism for flower color chimera of Prunus mume (Japanese apricot, mei). Using bisulfate sequencing and RNA sequencing, we analyzed the white (FBW) and red (FBR) petals collected from an individual tree of Japanese apricot cv. 'Fuban Tiaozhi mei to reveal the different changes in methylation patterns associated with gene expression leading to significant difference in anthocyanins accumulation of FBW (0.012 +/- 0.005 mg/g) and FBR (0.078 +/- 0.013 mg/g). It was found that gene expression levels were positively correlated with DNA methylation levels within gene-bodies of FBW and FBR genomes; however, negative correlations between gene expression and DNA methylation levels were detected within promoter domains. In general, the methylation level within methylome of FBW was higher; and in total, 4,618 differentially methylated regions (DMRs) and 1,212 differentially expressed genes (DEGs) were detected from FBW vs. FBR. We also identified 82 DMR-associated DEGs, and 13 of them, including PmBAHD, PmCYP450, and PmABC, were playing critical roles in phenylalanine metabolism pathway, glycosyltransferase activity, and ABC transporter. The evidence exhibited DNA methylation may regulate gene expression resulting in flower color chimera of Japanese apricot.