Combined Metabolomic and Transcriptomic Analysis Reveals Redirection of the Phenylpropanoid Metabolic Flux in Different Colored Medicinal Chrysanthemum Morifolium

As a medicinal and edible plant, Chrysanthemum morifolium cv. "Hangju" has economic value and is widely used as a Chinese herbal medicine and tea. However, the metabolomic difference between "Hangju" flowers with white and yellow petals is unclear. In this study, Chrysanthemum variety ZXYJ with white petals and its bud mutation strain JJYH with yellow petals were used as research materials. A preliminary study found that the relative content of total flavonoids in JJYH was 45.4% higher than that in ZXYJ. Combined transcriptomic and metabolomic analysis revealed that the phenylpropanoid biosynthetic pathway and the phenylalanine metabolic pathway had the highest degree of differentially expressed genes and significantly changed metabolites enrichment, respectively. The redirection of metabolic flux may contribute to increased accumulation of total flavonoid levels in JJYH, which may begin as early as phenylalanine metabolism. The results of this research provide a scientific basis for the development of products related to different colored medicinal chrysanthemums and references for the breeding of new varieties and the biosynthesis of phenylpropanoids.