Berry water content during development and at harvest is a crucial parameter of the vintage
quality by directly impacting the concentration of sugars and flavour compounds. In the last decade, there
has been considerable progress in understanding how berry water relations are involved in the ripening
process as a result of exploring and integrating developmental changes in berry hydraulic conductivity,
mineral nutrient loading, phloem unloading, xylem development, functionality of xylem vessels, cell
vitality, cell water relations, gene expression and the molecular biology of aquaporins (water channels). In
this chapter, we review the most recent advances in our understanding of the berry water influx and efflux
during development and their consequences on cell turgor and apoplast solute concentrations, taking
account of the changes in cell vitality observed late in ripening in some varieties. The role of aquaporins in
the regulation of berry water relations is also presented, with a particular emphasis on the varietal
differences observed in aquaporin functioning. Finally, the impact of water status of the parent vine on berry
ripening is discussed. From this review, it appears that the varietal differences observed at different
regulatory levels of berry water status represent a great opportunity to gain a better understanding of the
ripening process.
Keywords: Abcisic acid, Aquaporins, Cell turgor, Major intrinsic proteins, Transpiration, Turgor pressure,
Vine water status, Water deficit, Water relations, Xylem hydraulic resistance, Xylem vessels.
