Metabolomics analysis reveals metabolite diversity of the rare cliff plant Oresitrophe rupifraga unge.

ABSTRACT

Oresitrophe is monotypic, with the only species, Oresitrophe rupifraga Bunge, which is exclusive to China, having special growth and developmental traits due to its habitat. Furthermore, it has bright flowers and medicinal benefits. This study investigated the metabolites present in various tissues of Oresitrophe rupifraga Bunge. Using a widely targeted metabolomics approach, 1965 different metabolites were identified in Oresitrophe rupifraga Bunge. Based on principal component analysis (PCA) and orthogonal partial least squares discriminant analysis (OPLS-DA), the aboveground and underground metabolites of Oresitrophe rupifraga differed significantly. The comparison between bulblets and leaves revealed the differential expression of 461 metabolites, whereas the comparison between rhizomes and leaves showed the differential expression of 423 metabolites, and the comparison between bulblets and rhizomes showed the differential expression of 249 metabolites. The bulblets exhibited 49 metabolites that were higher and 412 metabolites that were lower than those of the leaves, whereas the rhizomes showed 123 upregulated and 300 downregulated metabolites. Bulblets showed an increase in 18 metabolites and a decrease in 231 metabolites compared to the rhizomes. Leaves contain more phenolic acids than the rhizomes and bulblets, whereas the rhizomes and bulblets contain more terpenoids than the leaves. KEGG pathway analysis showed an association between metabolites and metabolic pathways, as well as their effect on the progression and maturation of Oresitrophe rupifraga Bunge. The research findings can provide some insight into the growth and developmental traits of Oresitrophe rupifraga Bunge, thus providing a theoretical foundation for cultivating and utilising this plant.