The role of solute accumulation, osmotic adjustment and changes in cell wall elasticity in drought tolerance in Ziziphus mauritiana (Lamk)

Abstract

Ber (Ziziphus mauritiana Lamk.) is a major fruit tree crop of the north-west Indian arid zone. In a study of the physiological basis of drought tolerance in this species, two glasshouse experiments were conducted in which trees were droughted during single stresscycles. In the first experiment, during a 13 d drying cycle, pre-dawn leaf water (ψleaf) and osmotic (ψπ) potentials in droughted trees declined from −0.5 and −1.4 MPa to −1.7 and −2.2 MPa, respectively, for a decrease in relative water content (θ) of 14%. During drought stress, changes in sugar metabolism were associated with significant increases in concentrations of hexose sugars (3.8-fold), cyclitol (scylloinositol; 1.5-fold), an..