Preliminary study of the influence of ripening on the polysaccharide content of different red grape varieties

Drought is one of the main challenges for viticulture in the context of global change. The choice of rootstock could be leveraged for vineyard adaptation to drought as we can improve plant performance without modifying the scion variety. However, most of the existing rootstocks, selected over a century ago, have a narrow genetic background which could compromise their adaptive potential.

In winemaking grapes, it is known that most aroma compounds are present as non-volatile precursors, such as glycosidic precursors. In fact, there is strong evidence supporting the connection between the content of aroma precursors and the aromatic quality of wine [1]. Acid hydrolysis is preferred to reveal the aroma potential of winemaking grapes, as it predicts more accurately the chemical rearrangements occurring during fermentation in acidic environments [2]. In this study, a method involving a fast fermentation followed by acid hydrolysis at 75ºC was used to evaluate the accumulation of aroma compounds over time in fractions obtained from six different varieties of winemaking grapes.

Atmospheric CO2 levels have been rising continuously since the industrial revolution, affecting crop physiology, yield and quality of harvest products, and grapevine is no exception [1]. Most of previously reported studies used potted plants in controlled environments, and explored grapevine response to relatively high CO2 levels, 700 ppm or more. The vineyardFACE, established in Geisenheim in 2012, uses a free air carbon dioxide enrichment (FACE) system to simulate a moderate (ambient +20%) increase in atmospheric CO2 in a vineyard planted with cvs. Cabernet-Sauvignon and Riesling grafted on rootstock 161-49 Couderc and SO4, respectively.

By dissecting the root system architecture (RSA) into its underpinning components (e.g. root emission, axial growth, radial growth, branching, root direction or tropism) and identifying the relationships between them, functional-structural 3D root models are promising tools for analyzing the diversity and complexity of root system phenotypes with Genotype × Environment interactions. The model parameters are assumed to be synthetic traits, less influenced by the environment, and consequently with less polygenic architectures than the integrative RSA traits they drive. Root models can serve as a basis for in silico development of root system ideotypes by highlighting the developmental processes and parameters that most likely influence RSA fitness.

Grapevine leaves are known to contain different polyphenols such as flavonols, catechins and stilbenes, which are known to act as main contributors for plant defense against pathogens (1). While the composition for some major cultivars has been studied, there is lack of systematic comparison about the content of these compounds in the wide ecodiversity of Vitis vinifera cv. Recent advances in Mass Spectrometry-based Metabolomics allow a wider and more sensitive description of these polyphenols, as instance of those present in leaves (2). Such information could help to better explain leaf traits regarding the development of the leaf or to the plant tolerance to a pathogen. Moreover, these compounds offer appealing applications for human health due to their antioxidant activities.