Integrated MultiOmics Analysis Sheds Light on the Mechanisms of Color and Fragrance Biosynthesis in Wintersweet Flowers

Wintersweet (Chimonanthus praecox) is known for its flowering in winter and rich floral aroma, and it’s the whole flower is yellow or the inner petals are red. In this study, we choose the wintersweet genotypes HLT040 and HLT015 (belonging to the C. praecox 'Luteus' group and C. praecox 'Grandiflorus' group, respectively) as the re-search materials, and studied the co-regulatory mechanism of color and fragrance of wintersweet through metabolomics and transcriptomics. This study found that there were more flavonoids in HLT015, and anthocyanins (Cyanidin-3-O-rutinoside and Cyanidin-3-O-glucoside) were only present in HLT015, but HLT040 contained more monoterpenes and FVBPs (phenylpropanoid volatile compounds) than HLT015. We constructed putative benzenoids and phenylpropanoid metabolism pathway as well as terpene metabolism pathways. We found some linkages between the different struc-tural genes and metabolites in flower color and fragrance of wintersweet, and screened out 34 TFs that may be related to one or more structural genes in benzenoids and phenylpropanoid or terpene metabolism pathways. This study provided a theo-retical basis for understanding the co-regulatory mechanism of color and fragrance in wintersweet.