Rosa rugosa is not only cultivated as an excellent landscaping plant, but also serviced in cosmetics, medical and food industries. However, little information is currently available on the gene regulatory networks involved in its scent and color biosynthesis and metabolism. In this study, R. rugosa Thunb. f. rosea Rehd (RR) with red petals and its white petals variant (WR), were used as materials to study the molecular mechanism in flower color and scent. 65 differential flavonoid metabolites and 15 volatiles were found to be significant difference between WR and RR. Correspondingly, the key regulators (MYB-bHLH-WD40) of anthocyanin synthesis pathway and their structural genes that involved in flavonoid biosynthesis, benzenoid/phenylpropanoid biosynthesis, terpenoid biosynthesis pathways were also detected to be differentially expressed by comparative transcriptome. Furtherly, qPCR permitted the identification of some transcripts encoding proteins that putatively associated with scent and color biosynthesis in roses. Particularly, it showed that the ACT gene (encoding CoA geraniol/citronellol acetyltransferase) was involved in three pathways: flavonoid biosynthesis, phenylpropanoid biosynthesis and terpenoid biosynthesis pathways, and GT5 (anthocyanin modification gene) involved in both flavonoid and phenylpropanoid biosynthesis pathway, due to their higher expression in WR. These results suggested that ACT and GT5 might play important roles in regulating the relationship of color pigmentation and volatile releasing.
Less...