Integrated Metabolomic and Transcriptomic Analyses of the Flavonoid Biosynthetic Pathway in Relation to Color Mutation in Roses

The color of flowers constitutes one of the most significant ornamental characteristics in roses. Red pigmentation in rose flowers is generally controlled by the biosynthetic pathway of anthocyanins. In this study, the red petals from the rose cultivar 'Silk Road' (SR) and the white petals from its color mutant 'Arctic Road' (AR) were investigated. Transcriptomic and metabolomic analyses were utilized to identify the crucial genes and metabolites associated with the biosynthesis of flavonoids. A total of 479 flavonoid- related metabolites and 39,201 genes were detected in the rose petals. Comparative analyses revealed significant differences in 277 metabolites and 2556 genes between the blooming flowers of AR and SR. The contents of 11 anthocyanins, 11 proanthocyanidins, as well as the expression levels of <i>CHS</i>, <i>ANS, 3GT, COMT,</i> and <i>CCoAOMT</i> differ significantly between the two cultivars, which may contribute to the formation of white petals in AR. Additionally, 5 <i>GSTs</i>, 4 <i>ABCCs</i>, and 8 <i>MATEs</i> were found to be downregulated in AR, potentially resulting in reduced sequestration of anthocyanins in petal vacuoles. Through comprehensive data analyses, the correlations between genes and metabolites associated with anthocyanin variation in rose petals were identified. The <i>MYB</i> gene (<i>Chr1g0360311</i>) may serve as a key regulator in anthocyanin biosynthesis. This study offers new perspectives on the specific genes and metabolites regulating petal pigmentation, as well as the molecular mechanisms underlying flavonoid synthesis in roses. The candidate key genes associated with anthocyanin biosynthesis and sequestration could serve as important genetic resources for developing ornamental plant varieties with specific pigmentation traits.