Plant hydraulics: recent advances and some perspectives in the grapevine

Abstract

Over the last few decades, the study of the grapevine water status has been the focus of much attention. Numerous indicators, direct and indirect, of plant water status have been put forward and tested. Among such indicators, the following can be mentioned:  water potential, stomatal conductance, sapflow, canopy or leaf temperatures and the isotopic signatures in leaves and fruits.  In addition, major advances have been made in the development of water balance models or integrated indexes which encompass soil-related, climatic and physiological parameters interacting with the grapevine water status.  Recently, new techniques and measuring methods have enabled the study of phenomena linked to the failure of hydraulic conductivity in the grapevine’s vascular system (xylem embolism formation), which mostly affect the stomatal control of gas exchange (transpiration and C-assimilation), the growth and the yield during water stress.  An improved knowledge of the structure and hydraulic functioning of the grapevine’s vascular system proves to be necessary for a better understanding of the physiological mechanisms of adaptation during water stress.