Integrated Analyses of Metabolome and RNA-seq Data Revealing Flower Color Variation in Ornamental Rhododendron simsii Planchon

Planchon is an important ornamental species in the northern hemisphere. Flower color is an important objective of breeding programs. However, information on anthocyanin synthesis in is limited. In this research, the regulatory mechanism of anthocyanin biosynthesis in was performed through the integrated analysis of metabolome and RNA-seq. A total of 805 and 513 metabolites were screened by positive and negative ionization modes, respectively, In total, 79 flavonoids contained seven anthocyanidins, 42 flavanones, 10 flavans, 13 flavones, and seven flavonols. Methylated and glycosylated derivatives took up the most. Differentially accumulated metabolites were mainly involved in "flavone and flavonol biosynthesis", "cyanoamino acid metabolism", "pyrimidine metabolism", and "phenylalanine metabolism" pathways. For flavonoid biosynthesis, different expression of , , , , , , , , and genes ultimately led to different accumulations of quercetin, myricetin, cyanidin, and eriodictyol. In flavone and flavonol biosynthesis pathway, differential expression of , and genes led to the differential accumulation of quercetin, isovitexin, and laricitrin. This research will provide a biochemical basis for further modification of flower color and genetic breeding in and related species.