Impact of grapevine red blotch disease on primary and secondary metabolites in 'Cabernet Sauvignon' grape tissues

The grapevine red blotch disease (GRBD) was first noticed in 2008, impacting grape ripening. In general, GRBD reduces grape and wine quality resulting in significant economic losses. The purpose of the present study was to evaluate the effect of GRBD on agronomical parameters of 'Cabernet Sauvignon' vines at harvest. Using a metabolomics approach, the influence on primary and secondary metabolite profiling in skin + pulp/flesh and seeds were also determined. GRBD influenced °Brix and berry weight, as well as primary and secondary metabolites in both tissues. 1D ¹H NMR was effective in quantifying the main primary and secondary metabolites affected by GRBD. RP-HPLC was similarly able to quantify the main phenolics affected. Multivariate analysis showed the influence of the virus on grape metabolites using both tools in two berry tissues. The effectiveness of both tools to describe sample variability was compared and the most affected metabolites in each tissue could be identified.