The effect of abscisic acid (ABA) at 0 and 100 µM on some morphometrical, and phytochemical parameters and mineral nutrient changes of grapevine (Vitis vinifera L. cv. ‘Sultana’) were examined during ten weeks salinity stress (NaCl; 0, 25, 50 and 100 mM). At the end of first week of saline treatments, the vines were sprayed with ABA twice a day at a 12 h interval. Under saline condition, the plants height, leaves number, leaves area and shoots dry matter decreased significantly compared to the control non-saline stressed vines, but these parameters were improved in 100 µM ABA- treated vines under saline condition. The increase in leaf electrolyte leakage, lipid peroxidation and hydrogen peroxide production in cell biomembranes caused by salinity stress were reduced in 100 µM ABA- sprayed vines. Moreover, leaf relative water content, proline, soluble sugars, total phenolic, and flavonoids increased in these vines compared to non- ABA-treated vines under salinity condition. ABA (100 µM) had an additive effect on leaf antioxidant enzymes (catalase, guaiacol peroxidase and ascorbate peroxidase) activities of salt-stressed vines. Salt stress affects negatively the leaf elements concentrations, however ABA (100 µM) improved their accumulation. These ABA- induced morphometrical and phytochemical changes improved the ability of grapevine plants to mitigate NaCl toxicity under saline condition.
