Développement de l’appareil végétatif et maturation du raisin sur quatre sols de Pomerol en 1995

From fruit set to ripening, the grape berry mesocarp experiences a wide range of dynamic physical, physiological, and biochemical changes, such as mesocarp cell death (MCD) and hydraulic isolation. The premature occurrence of such events is a characteristic of the Niagara Rosada (NR) variety, utilised as table grapes and winemaking. In our opinion, the onset of ripening would not cause MCD, but a down-regulation of respiratory enzymes during the early loss of cell viability, while maintaining membrane integrity. For this, we investigated three distinct developmental stages (green (E-L33), veraison (E-L35), and ripe (E-L39)) of NR berries by label-free proteomics, enzymatic respiratory activity and outer mesocarp imaging. Cell wall-modifying proteins were found to accumulate differently throughout ripening, while cytoplasmic membranes continue intact.

Global warming has enhanced the frequency and severity of drought events, hence calling for a better management of water resources in the vineyard and for an improvement of breeding platforms. Somatic embryogenesis (SE) (i.e. the initiation of embryos from somatic tissues) can spontaneously generate new genetic variability, which results from genetic mutations, changes in epigenetic marks, or phenotypic alterations.
This study was tailored to test whether vines in vitro regenerated through SE (i.e. somaclones), can tolerate water deprivation better than the mother plant.

Grapevines are susceptible to freezing damage at temperatures below -5°F during the winter season. Preventing winter injury to grapevines is a major challenge in many grape-producing regions. Conventional methods such as hilling-up soil over graft unions have been developed as winter protection methods for preventing vine loss. However, these practices have drawbacks such as soil erosion, vine damage and crown gall development.

Insufficient levels of malate and lack of acidity in commercial grape cultivars (V.vinifera) hinders the quality of fruit grown in warm climates. Conversely, excessive levels of malate and sourness in wild Vitis grape, leads to unpalatable fruit and complicates the introgression of valuable disease resistant alleles through breeding. Nonetheless, albeit decades of research, knowledge regarding the molecular regulation of malate levels in grape remains limited.

SO2 is an additive widely used as antimicrobial in winemaking industry. However, this compound can negatively affect health, so the search for alternatives is currently a line of research of great interest. One of the proposed alternatives to SO2 as an antimicrobial is the use of bioprotection yeasts, which colonize the medium preventing the proliferation of undesirable microorganisms.