Effects of dimethomoph on metabolism of grape leaves

【Objective】 To explore the effects of dimethomoph, a carboxylic amidesfungicide, on the differences of metabolites and metabolic pathways on grape leaves, so as to provide reference for further clarifying the effects of carboxylic amides on metabolism of grape leaves.【Method】 Healthy Red Globe grape which had not been applied by fungicides underrain shelter culture was taken as the research object. During the growth and development period, it was sprayed with dimethomoph pesticide(DI) and the same amount of sterile water was as control(CK). Ultra performance liquid chromatography-tandem mass spectrometry(UPLC-MS) technique was used to research metabolic differences in healthy grape leaves under two different treatments.【Result】 The results of partial least squares regression discriminant analysis and displacement test showed that there were significant differences in metabolites between the two groups of grape samples (P<0.05, the same below). Further, orthogonal partial least squares discriminant analysis combined with displacement test found that there were different metabolites in the two groups of grape leaves, and 39 main metabolites causing significant differences in the metabolism of grape leaves between the two groups were screened.The differential metabolites significantly changed after treatment with dimethomoph were mainly divided into seven categories:lipids and lipid molecules, phenylpropane and polyketones, organic acids and their derivatives, organic oxygen compounds, alkaloids and their derivatives, organic nitrogen compounds and other compounds. The contents of key antagonistic hormones salicylic acid and jasmonic acid, resistance related substances ampelopsin and epsilon-viniferin were analyzed. The results showed that the above substances contents were affected by the application of dimethomoph. Through the enrichment analysis of KEGG pathway, it was found that the differential metabolites were mainly enriched in four metabolic pathways:flavonoid biosynthesis pathway, flavonoid and flavonol biosynthesis pathway, niacin and niacinamide metabolic pathway, steroid biosynthesis pathway.【Conclusion】 The application of dimethomoph can directly or indirectly affect the metabolism on grape leaves.In agricultural production, dimethomoph should be used according to the recommended concentration, then it can have some positive effect on grape, so as to promote its quality improvement.