Curcuminoid metabolite synthesis pathway analysis based on integration of RNA-seq and metabolite data
Li Donghan ( 1361018 )
Write your presentation abstract here and put the paragraph delimiter at the end of paragraph.The powdered rhizome of turmeric (Curcuma longa) has been used as a traditional medicine in Asian countries. Curcuminoids are secondary metabolites which act as the primary active constituents of turmeric. To understand the curcuminoids synthesis pathway, we compared two wild strains and two cultivars to understand the differences in the synthesis pathway. Because the fluxes of metabolic reactions depend on the amounts of their substrate and the activity of the catalysts, we analyzed the metabolite concentrations and gene expression of the enzymes. The RNA sequencing (RNA-seq) analysis based on Next-Generation Sequencing (NGS) technology not only provide us the gene sequence but also the gene expression level. By comparing the genes expression level of the 4 specimens both from leaves and rhizomes, we can determine the genes whose expression level significantly changes between the leaves and rhizomes. Considering the fact that rhizome of the turmeric is used as herb and a large amount of medicinal component curcuminoid is accumulated in the rhizome, we next focused on the metabolic pathway that synthesizes curcuminoids, in order to understand the difference in curcuminoid concentrations among the four specimens. We developed a ‘selection first’ method for RNA-seq analysis in which short reads are mapped to selected enzymes in the biosynthetic pathways in order to reduce the effect of mapping errors. Using this method, we found that there were significant changes in expression levels of the enzymes at the branching point of the curcuminoids biosynthesis pathway, which is consistent with the observed curcuminoid contents.