The <em>Microvine</em>, a plant model to study the effect of vine-shoot extract on the accumulation of glycosylated aroma precursors in grapes

International audienceBACKGROUNDThe Microvine plant model displays unique reproductive organ behavior and is suitable for grapevine fruit physiological studies, allowing one to undertake studies up to five times more rapidly than the current situation with grapevines. Recently, vine-shoot aqueous extracts, which have an interesting phenolic and aroma composition, have been proposed as viticultural biostimulants, since their post-veraison foliar application to grapevines impacts the wine aroma profile. Using Microvines, the aim of this study was to determine the effect of vine-shoot extract foliar application on 21 stages of grape development. The application was carried out from BBCH 53 (inflorescences clearly visible) to BBCH 85 (softening of berries) to reveal stage-specific responses of the accumulation of glycosylated aroma precursors at BBCH 89 (berries ripe for harvest), the phenological stage selected to study the treatment effect. RESULTSMicrovine use made it possible to carry out 15 sampling time points during 86 days of the experiment, which were established by the cumulative degree days (CDD) parameter. The results confirmed that vine-shoot extract treatment had a positive impact on total glycosylated compounds, especially aglycones such as alcohols, terpenes and C-13-norisoprenoids, with a higher effect when the treatment was applied during ripening. CONCLUSIONExtrapolation of the results to grapevines suggests that vine-shoot extract treatment could modulate the synthesis of grape glycosylated aroma precursors