基于 LC-MS/MS 分析马缨杜鹃花代谢物的变化

In order to analyze the differences of metabolites and their pathways from floweropening to withering of Rhododendron delavayi, we used LC-MS/MS material separation andidentification technique to non-targeted the chemical components of bud stage, dehiscence stage,pollination stage, blooming stage, senescence stage and withering stage. The results were asfollows: (1) A total of 973 kinds of metabolites were detected, mainly including flavonoids,organic acids, phenolic acids, amino acids and their derivatives, lipids, alkaloids and so on. (2)Principal component analysis (PCA) shows that there were differences in metabolites amongsamples. Combined with orthogonal partial least squares discriminant analysis (OPLS-DA), Pvalue of t-test and fold change (Fc) of univariate analysis, differential metabolites (VIP > 1, P 2 or Fc < 0.5) were screened out, involving 591 species, the quantity and expression ofdifferential metabolites increased significantly after the Rhododendron delavayi flower stageentered the senescence stage and the withering stage, in which the expression of differentialmetabolites from bud stage to dehiscence stage was mainly down-regulated, while the expressionof differential metabolites was mainly up-regulated after entering senescence stage and witheringstage. (3) 68 differential metabolic pathways were annotated by KEGG, of which 3 pathways weresignificantly enriched with differential metabolites (P < 0.01), including phenylpropanoidsbiosynthesis, plant hormone biosynthesis and flavonoid biosynthesis. (4) Based on the analysis ofbiosynthetic pathways of phenylpropanoids, flavonoids and other effective components, 10 kindsof differential metabolites were screened from flowering to withering of Rhododendron delavayi,including L-phenylalanine, trans-cinnamic acid, chalcone, naringenin, p-coumaroyl shikimic acid,ferulic acid, coniferyl alcohol, sinapic acid, syringin and quercetin. In addition, the differentialmetabolites of effective components showed that phenylpropanoids biosynthesis and metabolismactivities gradually increased with the development of Rhododendron delavayi, while flavonoidbiosynthesis gradually decreased. These key differential metabolites may play an important role inregulating the development of Rhododendron delavayi. This research provides a metabonomicbasis for the study of effective components in the metabolic pathway during the flowering andwithering process of Rhododendron delavayi, and provides a reference for the further study of themolecular mechanism of flowering regulation of Rhododendron delavayi.