A comparison of the metabolomic response of grapevine to infection with ascomycete wood-infecting fungi

Abstract

Fungi that cause grapevine trunk diseases, including Diplodia seriata, Eutypa lata, Neofusicoccum parvum, and Phaeomoniella chlamydospora, all colonize woody tissues, but lesions develop to different extents. Such variation is thought to correspond to fungal virulence, but it may also reflect host metabolic responses to limit colonization. From the woody stems of potted Vitis vinifera ‘Cabernet-Sauvignon’ in the greenhouse, we measured wood lesions and quantified metabolites at the lesion margins. Amino acids, sugars, phenolics, and terpenoids were quantified by appropriate chromatography techniques. At 3 months post-inoculation (MPI) lesions from P. chlamydospora and N. parvum were larger than those of D. seriata and E. lata. Among all pathogen treatments, compared to controls, lower concentrations of terpenoids at 0.5 MPI were followed at 2 MPI by higher concentrations of some phenolic compounds. Lesion length did not correlate with primary metabolites, but larger lesions did correlate with higher phenolic concentrations and lower terpenoid concentrations.