Could foliar applications of methyl jasmonate and methyl jasmonate + urea improve must grape aroma composition?

Epiphytic bacterial consortia drive growth regulation in potato under methyl jasmonate elicitation: A leaf surface multi-omics perspective

Methyl jasmonate (MeJA), a lipid-derived signaling molecule widely reported as a plant growth regulator, was revealed in this study to coordinate oxidative stress adaptation and delay senescence in potato through metabolite-microbe interactions, ultimately improving yield. MeJA triggered leaf oxidative stress while integrating rapid enzymatic scavenging, sustained osmoprotectant accumulation, and membrane stabilization, effectively delaying senescence initiation. Metabolic reprogramming under MeJA suppressed endogenous jasmonic acid synthesis while promoting saturated fatty acid biosynthesis, altering leaf surface lipid composition. These lipid changes, combined with MeJA-induced alkaloids, drove functional restructuring of phyllosphere epiphytic bacteria through fatty acid-mediated niche specialization, enhancing bacterial metabolism and enriching stress-resistant Proteobacteria. Notably, the enrichment of saturated fatty acids correlated with microbial taxa exhibiting specialized lipid metabolism. Field trials demonstrated that 200 μmol/L MeJA optimized redox homeostasis and photosynthetic longevity in early-maturing cultivar 'Favorita', translating delayed senescence into significant yield increases. This study proposes a "metabolite-guided microbial niche construction" model, where host lipid metabolism and secondary metabolites jointly shape stress-adapted microbial communities, providing new strategies for precision agrochemical design targeting phyllosphere microbiome engineering.

Effects of foliar application of methyl jasmonate and/or urea, conventional or via nanoparticles, on grape volatile composition

BACKGROUND

Viticulture has adapted foliar applications of biostimulants as a tool to improve crop quality. Recently, nanotechnology has been incorporated as a strategy to reduce the loss of biostimulants and treat nutrient deficiencies. Therefore, the present study aimed to investigate the effect of foliar applications of amorphous calcium phosphate nanoparticles (ACP) doped with methyl jasmonate (ACP-MeJA) and urea (ACP-Ur), individually or together (ACP-MeJA+Ur), on the content of volatile compounds in 'Tempranillo' grapes, compared to the conventional application of MeJA and Ur, individually or in combination (MeJA+Ur).

RESULTS

The results showed that nanoparticle treatments reduced the total C6 compounds and some carbonyl compounds in the grape musts. This is of novel interest because their presence at high levels is undesirable to quality. In addition, some aroma-positive compounds such as nerol, neral, geranyl acetone, β-cyclocitral, β-ionone, 2-phenylethanal and 2-phenylethanol increased, despite applying MeJA and Ur at a lower dose.

CONCLUSION

Consequently, although few differences in grape volatile composition were detected, nanotechnology could be an option for improving the aromatic quality of grapes, at the same time as reducing the required doses of biostimulants and generating more sustainable agricultural practices. © 2024 The Author(s). Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Metabolite profiling reveals the influence of grapevine genetic distance on the chemical signature of juices

BACKGROUND

Yield, disease tolerance, and climate adaptation are important traits in grapevine genetic breeding programs. Selection for these characteristics causes unpredictable changes in primary and specialized metabolism, affecting the physicochemical properties and chemical composition of the berries and their processed products, juice, and wine. In this study, we investigated the influence of the genetic distance between grapevine genotypes on the chemical signatures of the juices, by integrating comprehensive metabolic profiling to genetic analyses.

RESULTS

The studied grapevine cultivars exhibited low genetic diversity. Breeding for agronomic traits promoted higher contents of soluble sugars, total phenolics, and anthocyanins in the juices. Untargeted juice metabolomics identified a total of 147 metabolites, consisting of 30 volatiles, 21 phenolics, and 96 ultra-high-performance liquid chromatography-mass spectrometry (UHPLC-MS) features. Juices from grapes of the most recent cultivars exhibited increased levels of trans-resveratrol, catechin, and luteolin. The blend of volatiles from juices of later cultivars was also more complex, consisting of 29 distinct metabolites in 'BRS Magna'. Grapes from 'BRS Carmem', an intermediate cultivar, gave the most divergent UHPLC-MS juice profile.

CONCLUSION

Contents of soluble solids, total phenolics, and anthocyanins in grape juices were increased by controlled crosses and hybrid selection. Integrative analyses demonstrated that the juices' metabolic profiles accurately represent the cultivars' genetic distances. Juices from 'BRS Violeta' and 'BRS Magna' show relevant positive association with health-related phenolics and a distinct set of odor volatiles, although these characteristics were specifically sought by breeding. © 2023 Society of Chemical Industry.