Integrated Analysis of Metabolomics and Transcriptomics of the Differences in Flower Colors of Hybrid Cherry Blossoms

Flower color, as an important trait of ornamental plants, has been a research hotspot in recent years. In this study, we selected Prunus campanulata (Maxim.) (ZH, red), P. dielsiana (Schneid.) (WH, white), and two cherry blossom varieties ‘Yanzhi Fei’ (FH, deep pink) and ‘Yanzhi Xue’ (XH, pinkish white) obtained by open-pollination hybridization as material. By means of bioinformatics methods such as metabolomics and transcriptomics, it is expected to deeply study the molecular mechanism of the gradient changes in flower color between the parents and offspring of cherry blossoms. Metabolomics analysis indicated that a total of 84 flavonoid related metabolites were identified, among which 31 were associated with the anthocyanin metabolic pathway, including three major types of anthocyanin substances: cyanidin, delphinidin, and malvidin. Transcriptome analysis showed that a total of 7712 differential genes were detected between P. campanulata and P. dielsiana; there were 3948 differential genes between P. campanulata and ‘Yanzhi Xue’, 2802 between P. campanulata and ‘Yanzhi Fei’, and 2511 between ‘Yanzhi Xue’ and ‘Yanzhi Fei’. After screening based on anthocyanin accumulation, nine key enzyme genes were obtained. Joint analysis showed that the relative expression trends of structural genes such as PAL, 4CL, CHI, DFR, and CYP75B in the samples were consistent with those of anthocyanins, and they had a high correlation with downstream metabolites. The results of this study lay a certain scientific foundation for the future directional improvement and breeding of cherry blossom colors.