Grapevine drought stress physiology: towards an integrative definition of drought tolerance.

: Water availability is arguably the most important environmental factor limiting crop growth and productivity. Erratic precipitation patterns and increased temperatures resulting from climate change will likely make drought events more frequent in many regions, increasing the demand on freshwater resources and creating major challenges for agriculture. Addressing these challenges through increased irrigation is not always a sustainable solution so there is a growing need to identify and/or breed drought tolerance crop varieties in order to maintain sustainability in the context of climate change. Grapes, a major fruit crop of economic importance, have emerged as a model perennial fruit crop for the study of drought tolerance. This review synthesizes the most recent results on grapevine drought responses, the impact of water deficit on fruit yield and composition, and the identification of drought tolerant varieties. Given the existing gaps in our knowledge of the mechanisms underlying grapevine drought responses this review aims to answer the following question: How can we move towards a more integrative definition of grapevine drought tolerance?