A. Patakas et B. Noitsakis, Mechanisms involved in diurnal changes of osmotic potential in grapevines under drought conditions, J PLANT PHY, 154(5-6), 1999, pp. 767-774
The aim of this study was the quantitative determination of the contributio
n of various possible mechanisms involved in diurnal changes of osmotic pot
ential in grapevine leaves (Vitis vinifera L., cv. Victoria) under water st
ress conditions. Results of this study revealed that dehydration accounted
for 36 % of the diurnal changes in osmotic potential in stressed plants. Th
e relative contribution of changes in non-osmotic volume was negative. Net
solute accumulation accounted for 73 % of the diurnal changes, indicating t
he occurrence of an active osmotic adjustment during the day in stressed pl
ants. There was evidence that compounds other than sugars contributed to di
urnal osmotic adjustment in stressed grapevines.