Abstract: This study aimed to analyze the differences in the metabolite profiles and related metabolic pathways among different rootstock-scion combinations of Cabernet Sauvignon (CS). Liquid chromatography-mass spectrometry (LC-MS)-based non-targeted metabolomics was used to analyze the metabolites in grape skins from CS grafted to 1103P, 5C, SO4, 3309C, 140R and CS rootstocks. Multivariate statistical analyses including principal component analysis (PCA), partial least squares-discriminant analysis (PLS-DA) and orthogonal-partial least squares discriminant analysis (OPLS-DA) showed that a total of 32 metabolites significantly differed (P < 0.05, VIP ≥ 1) among the six rootstock-scion combinations, and 22 related metabolic pathways were found. The results showed that the rootstocks could affect the contents of metabolites such as organic acids and polyphenols in grape skins by controlling metabolic pathways involved in the biosynthesis of isoquinoline alkaloids, flavonoids (flavonols), pantothenic acid and coenzyme A, and the citric acid cycle, thereby altering the quality of grapes. This study can provide a theoretical basis for the selection of grape rootstock-scion combinations, and also provide important inspiration for improving the quality of grape-based products.

Key words: liquid chromatography-mass spectrometry; grape skin; scion-rootstock combinations; metabolomics