Somatic embryogenesis and polyploidy in grapevine: morphological shoot and leaf traits variations

Yeast cell walls (CWs) may adsorb wine components with a significant impact on wine quality. When dealing with red wines, this adsorption is mainly related to physicochemical interactions between wine polyphenols and cell wall mannoproteins. However, mannoproteins are a heterogeneous family of complex peptidoglycans including long and highly branched N-linked oligosaccharides and short linear O-linked oligosaccharides, resulting in a huge structural diversity.

Grapevine (Vitis spp.) is greatly influenced by climatic conditions and its economic value is therefore directly linked to environmental factors. Among these factors, temperature plays a critical role in vine phenology and fruit composition. In such conditions, elucidating the mechanisms employed by the vine to cope with heat waves becomes urgent. For the past few years, our research team has been producing molecular and metabolic data to highlight the molecular players involved in the response of the vine and the fruit to high temperatures [1]. Some of these temperature-sensitive genes are currently undergoing characterization using transgenesis approaches coupled or not with genome editing, taking advantage of the Microvine genotype [2].

The dealcoholized wine sector is experiencing strong market growth, driven by increasing consumer demand.

Bacterial malolactic fermentation (MLF) has a considerable impact on wine quality. The yeast strain used for primary fermentation can consistently stimulate (MLF+ phenotype) or inhibit (MLF- phenotype) malolactic bacteria and the MLF process as a function of numerous winemaking practices, but the molecular evidence behind still remains a mystery. In this study, such evidence was elucidated by the direct comparison of extracellular metabolic profiles of MLF+ and MLF- yeast phenotypes. Untargeted metabolomics combining ultrahigh-resolution FT-ICR-MS analysis, powerful machine learning methods and a comprehensive wine metabolite database, discovered around 800 putative biomarkers and 2500 unknown masses involved in phenotypic distinction.

Sono stati presi in considerazione alcuni dati agrometeorologici dell’Oltrepò Pavese (temperature e piovosità degli ultimi 80 anni) e gli studi delle curve di maturazione condotti in zona sul Pinot nero da spumante negli anni (1988-1991, 1999-2000, 2006-2008), si nota che l’aumento progressivo negli anni delle temperature attive (indice di Winkler) ha determinato un anticipo dell’invaiatura, definita dal parametro “punto di incrocio” (intersezione delle funzioni di zuccheri ed acidità nel tempo), con conseguente anticipo della data di vendemmia di circa 12-15 gg.