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

Methyl Jasmonate and Nanoparticles Doped with Methyl Jasmonate affect the Cell Wall Composition of Monastrell Grape Skins

The structural composition of the cell wall of grape skins is related to the cell wall integrity and subsequent extraction of the different compounds that are contained inside vacuoles and also the cell wall breakdown products. Different reports have established that methyl jasmonate (MeJ) produces changes in the composition of the grape skin cell wall. The use of elicitors to promote the production of secondary metabolites in grapes has been studied in several reports; however, its study linked to nanotechnology is less developed. These facts led us to study the effect of methyl jasmonate (MeJ) and nanoparticles doped with MeJ (nano-MeJ) on the cell walls of Monastrell grapes during three seasons. Both treatments tended to increase cell wall material (CWM) and caused changes in different components of the skin cell walls. In 2019 and 2021, proteins were enlarged in both MeJ and nano-MeJ-treated grapes. A general decrease in total phenolic compounds was detected with both treatments, in addition to an increment in uronic acids when the grapes were well ripened. MeJ and nano-MeJ produced a diminution in the amount of cellulose in contrast to an increase in hemicellulose. It should be noted that the effects with nano-MeJ treatment occurred at a dose 10 times lower than with MeJ treatment.

The Cell Wall Regeneration of Tobacco Protoplasts Based on Microfluidic System

The cell wall, serving as the exoskeleton of plants, is naturally a barrier to resist external stresses. Protoplasts can be obtained by dissolving the cell walls of plant cells without damaging the cell membrane, and are widely used in the rapid propagation, transgenic breeding, and somatic hybridization of plants. However, to regenerate the cell wall is a precondition for cell division. Therefore, to study the culture condition and influencing factors during the cell wall regeneration of protoplasts is vital. Traditionally, culture medium is used to cultivate protoplasts, but it has some disadvantages. Herein, a microfluidic system with crossed channels was constructed to isolate and cultivate the protoplasts of tobacco. Then, the cell wall regeneration of the tobacco protoplasts was also studied based on this microfluidic system. It was found that, compared with the control, benzo-(1, 2, 3)-thiadiazole-7-carbothioic acid S-methyl ester (BTH) could accelerate the regeneration of the cell wall, while Pseudomonas syringae pv. tomato DC3000 (Pst DC3000) could inhibit the regeneration of the cell wall within 24 h. To conclude, this study demonstrated that a crossed microfluidic chip could be an effective tool to study cell wall regeneration or other behavior of plant cells in situ with high resolution. In addition, this study revealed the rate of cell wall regeneration under BTH and Pst DC3000 treatment.

Effect of Methyl Jasmonate and Methyl Jasmonate Plus Urea Foliar Applications on Wine Phenolic, Aromatic and Nitrogen Composition

Foliar application has been studied to enhance grape composition and, therefore, wine quality. This work examined, for first time, the effects of foliar applications of methyl jasmonate (MeJ) and methyl jasmonate plus urea (MeJ+Ur) to Tempranillo vineyard on wine phenolic, aromatic and nitrogen composition over two vintages (2019 and 2020). A reduction in alcoholic degree was observed in MeJ and MeJ+Ur wines. The effect of foliar treatments was season-dependent. MeJ and MeJ+Ur wines were characterized, in the first vintage, by a higher content of total acylated anthocyanins, but a low content of total esters, alcohols and acids when compared with control wines. MeJ+Ur wines presented a higher total amino acids content than control and MeJ wines. However, in the second vintage, MeJ and MeJ+Ur wines presented an increase in some non-acylated anthocyanins, but only MeJ+Ur treatment increased the total content of flavonols, flavanols, hydroxycinnamic acids, stilbenes and total amino acids when compared with control wines. MeJ wines presented a low content of esters and acids, whereas MeJ+Ur did not show differences with control wines. Overall, the effect of MeJ+Ur foliar treatment was greater than the effect of MeJ application in order to improve the wine chemical composition.

Relationship between anthocyanins, proanthocyanidins, and cell wall polysaccharides in grapes and red wines. A current state-of-art review

Numerous research studies have evaluated factors influencing the nature and levels of phenolics and polysaccharides in food matrices. However, in grape and wines most of these works have approach these classes of compounds individually. In recent years, the number of publications interconnecting classes have increased dramatically. The present review relates the last decade's findings on the relationship between phenolics and polysaccharides from grapes, throughout the entire winemaking process up to evaluating the impact of their relationship on the red wine sensory perception. The combination and interconnection of the most recent research studies, from single interactions in model wines to the investigation of the formation of complex macromolecules, brings the perfect story line to relate the relationship between phenolics and polysaccharides from the vineyard to the glass. Grape pectin is highly reactive toward grape and grape derived phenolics. Differences between grape cultivars or changes during grape ripeness will affect the extractability of these compounds into the wines. Therefore, the nature of the grape components will be crucial to understand the subsequent reactions occurring between phenolics and polysaccharide of the corresponding wines. It has been demonstrated that they can form very complex macromolecules which affect wine color, stability and sensory properties.

Recent advances in the knowledge of wine oligosaccharides

Oligosaccharides are carbohydrates with a low polymerization degree containing between three and fifteen monosaccharide residues covalently linked through glycosidic bonds. Oligosaccharides are related to plant defense responses and possess beneficial attributes for human health. Research has focused in wine oligosaccharides only in the last decade. In this paper, a summary of these works is provided. They include: (i) wine oligosaccharides origins, (ii) techniques for isolating oligosaccharide fraction and determining their content, composition and structure, (iii) their dependence on the grape origin and cultivar and winemaking process, and (iv) the connection between oligosaccharides and wine sensorial attributes. Further research is required regarding the impact of agricultural aspects and winemaking techniques on wine oligosaccharides. The knowledge concerning their influence on sensorial and physicochemical properties of wines and on human health should also be improved. The implementation of laboratory methods will provide better understanding of these compounds and their performance within wine's matrix.

Effects of fertigation by elicitors enriched in amino acids from vegetal and animal origins on Syrah plant gas exchange and grape quality

Nutrition management of vines is a key factor that regulates production and determines grape quality. Currently, one of the main objectives of fertilization is to apply eco-friendly and balanced nutrition. In this case, fertigation is the most efficient strategy. The objective of this work was to assess the effect of innovative fertilizers on Syrah grapevines. The tested products contained an elicitor, macro- and microelements and amino acids from animal and vegetal origins. Fertilizers were applied by fertigation under field conditions in 2016, 2017 and 2018. The influence of the treatments on the grapevine gas exchange, element assimilation and oenological composition of must was evaluated. Additionally, the amino acid contents and volatile composition were determined. The results suggest that application of fertigation does not directly influence the water status of Syrah vines under the conditions of the study but can improve the gas exchange balance and N assimilation. Moreover, the leaf assimilation of Zn, Ca and, to a lesser extent, B were improved at the bloom stage, and the assimilation of Mn was improved at veraison. Small changes were observed in the basic parameters of musts, and an increase in yeast assimilable nitrogen was detected in treated vines. The aromatic profile of grape musts was enhanced in treated vines, and the elicitors enriched in vegetal amino acids could be a sustainable alternative for improving certain vegetative and grape quality parameters of Syrah.