Preharvest Application of Elicitors to Monastrell Grapes: Impact on Wine Polysaccharide and Oligosaccharide Composition

Abstract

This work studied the effect of preharvest application in Monastrell grapes of four different elicitors [methyl jasmonate (MeJ), benzothiadiazole (BTH), chitosan from fungi (CHSf), and chitosan from seafood (CHSs)] on wine polysaccharide and oligosaccharide fractions. The polysaccharide and oligosaccharide fractions were isolated and characterized. Neutral monosaccharides were released after hydrolysis of polysaccharides and quantified by gas chromatography (GC). Sugar composition of oligosaccharides was determined after solvolysis by GC of their per-O-trimethylsilylated methyl glycoside derivatives. MeJ, BTH, CHSf, and particularly CHSs decrease the polysaccharide content in wine. The oligosaccharide concentration was also reduced after both CHS treatments. These results pointed to a lower degradation of the skin cell wall from treated grapes. We suggested that the cause would be a reinforcement of the skin cell wall as a result of the action of these elicitors. In conclusion, the application of any of these four elicitors in the clusters of the vineyard affected the complex carbohydrate composition of elaborated wine.

Foliar applications to vines of methyl jasmonate and nanoparticles doped with methyl jasmonate: impact on grape and wine polysaccharide composition

“…In contrast, Apolinar-Valiente et al (2018) concluded that the application of methyl jasmonate, benzothiadiazole, chitosan from fungi, and chitosan from seafood elicitors in the clusters of the vineyard of Monastrell grapes affected the extraction of monosaccharides in the wines. In the 2019 and 2020 wines, the major monosaccharides differed: in terms of glycosylated residues, galacturonic acid and mannose showed the second highest levels in the 2019 and 2020 wines respectively, and mannose and arabinose the third highest levels in the 2020 and 2019 wines respectively.…”

“…The polysaccharides from the skin cell walls probably contributed more to TMS content in 2019 wines than those from pulp. The cell walls of the skin are rich in polysaccharides, because the cells are smaller, more compact and have thicker walls than the cells of the pulp (Apolinar-Valiente et al, 2018). Other authors also point out that the extractability of polysaccharides increases with grape maturity (Gil et al, 2012;Martínez-Lapuente et al, 2016).…”

“…Callose is a polysaccharide that contains a high proportion of glucose bound to 1,3-β. Lignin is a rigid, hydrophobic polymer usually presents in the secondary cell wall of vasculature (Apolinar-Valiente et al, 2018). The xylose residues were thus components of xyloglucans.…”

“…Applications to the grapevine of suitable elicitors and combinations of different stress stimuli can activate structural and biochemical response mechanisms (Lijavetzky et al, 2008;Benhamou, 1996). Grapevine responds to these stressors by activating an array of mechanisms similar to the defense responses to pathogen infections or environmental stresses (Apolinar-Valiente et al, 2018). The biochemical changes in the grape and leaves before a pathogen infection in the grapevine involve the accumulation of phenolic compounds and pathogenesis-related (PR) proteins (Lijavetzky et al, 2008).…”

“…These properties are associated with the sequential deposition of newly formed molecules including callose, lignin, phenolic compounds, and glycoproteins (Benhamou, 1996). Apolinar-Valiente et al (2018) observed a notable reinforcement of the skin cell wall in response to the application of four different elicitors to Monastrell grapes, one of which being methyl jasmonate (MeJ). Nevertheless, the extent of the reinforcement of the cell wall probably depends on the composition and morphology of the skin cell wall material, which is different for each grape crop (Apolinar-Valiente et al, 2016).…”