Analysis of Metabolic Differences of Rhododendron ovatum Flowers Based on Widely Targeted Metabolomics

To investigate mechanism of flower coloration of Rhododendron ovatum, petal samples of three flower colors were analyzed on the basis of widely-targeted metabolomics, obtaining 51 classes of 696 metabolites, most of which was flavonoid metabolites (108), followed by monoterpenoids(39). There were 345 different metabolites between pink-white and purple petals, 329 up-regulated and 16 down-regulated. 111 metabolites with significant differences were successfully annotated to 42 metabolic pathways. There were 217 different metabolites between light purple and purple petals, 193 up-regulated and 24 down-regulated. Sixty-seven metabolites with significant differences were successfully annotated to 31 metabolic pathways. There were 248 different substances between pink and white petals and light purple petals, 226 up-regulated and 22 down-regulated. 53 significantly different metabolites were successfully annotated to 22 metabolic pathways. The highest accumulation degree in the 3 comparison groups was the flavonoid biosynthesis pathway. Centaurin-3-o-glucoside played a significant role in regulating red color of R.ovatum, while delphinin also had some effect on the purple color. This study provides theoretical guidance for the transformation of the flower color of R.ovatum.