Wood Metabolomic Responses of Wild and Cultivated Grapevine to Infection with Neofusicoccum parvum, a Trunk Disease Pathogen

Abstract

Grapevine trunk diseases (GTDs), which are associated with complex of xylem-inhabiting fungi, represent one of the major threats to vineyard sustainability currently. Botryosphaeria dieback, one of the major GTDs, is associated with wood colonization by Botryosphaeriaceae fungi, especially <i>Neofusicoccum parvum</i>. We used GC-MS and HPLC-MS to compare the wood metabolomic responses of the susceptible <i>Vitis vinifera</i> subsp. <i>vinifera (V.v.</i> subsp<i>. vinifera)</i> and the tolerant <i>Vitis vinifera</i> subsp. <i>sylvestris (V.v.</i> subsp<i>. sylvestris)</i> after artificial inoculation with <i>Neofusicoccum parvum</i> (<i>N. parvum</i>). <i>N. parvum</i> inoculation triggered major changes in both primary and specialized metabolites in the wood. In both subspecies, infection resulted in a strong decrease in sugars (fructose, glucose, sucrose), whereas sugar alcohol content (mannitol and arabitol) was enhanced. Concerning amino acids, <i>N. parvum</i> early infection triggered a decrease in aspartic acid, serine, and asparagine, and a strong increase in alanine and -alanine. A trend for more intense primary metabolism alteration was observed in <i>V.v.</i> subsp<i>.</i> <i>sylvestris</i> compared to <i>V. v.</i> subsp<i>.</i> <i>vinifera</i>. <i>N. parvum</i> infection also triggered major changes in stilbene and flavonoid compounds. The content in resveratrol and several resveratrol oligomers increased in the wood of both subspecies after infection. Interestingly, we found a higher induction of resveratrol oligomer (putative E-miyabenol C, vitisin C, hopeaphenol, ampelopsin C) contents after wood inoculation in <i>V.v.</i> subsp<i>.</i> <i>sylvestris</i>.