Metabolomics combined with transcriptomics reveals the formation mechanism of different leaf colors of Heuchera micrantha

Introduction The vivid colors of color-leafed plants endow plants with unique ornamental value. At present, there are many researches focusing on the mechanism of flower color formation, while there is less interesting research on color-leafed plants. As an excellent color-leafed plant, Heuchera micrantha has only been studied for its pigment content and physiological characteristics, and the mechanism of color-leafed formation has not been characterized yet. Methods In this study, we used two varieties of Heuchera micrantha with green and red leaves as materials, and employed a combination of metabolomics and transcriptomics to reveal the molecular mechanisms underlying the formation of different color leaves. Results Through observation of phenotype, analysis of metabolomics and transcriptomics, and combined analysis of multi-omics, it was found that differential metabolites and differentially expressed genes were enriched in flavonoid metabolism and related pathways. Nine MYB and bHLH transcription-factor candidates implicated in flavonoid metabolism were selected and functionally annotated; five are predicted to act as activators and four as repressors of the flavonoid biosynthetic pathway. Discussion In summary, this study provides important insights into the coloring mechanism of color-leafed plants and provides gene reserves for subsequent targeted breeding.