RESPONSE OF ANTIOXIDANT SYSTEMS TO SHORT - TERM NaCl STRESS IN GRAPEVINE ROOTSTOCK - 1616 C AND VITIS VINIFERA L

The present study examined free-radical scavenging enzyme activity and the levels of lipid peroxide, ascorbic acid, nitric oxide and glutathione in 1616C rootstock and the Razaki cultivar of Vitis vinifera L. under treatment with different concentrations of salt. At day 7, in leaves of both 1616C rootstock and cv. Razaki treated with 12 mM NaCl there were significant increases in glutathione peroxidase and catalase activity, and in the levels of thiobarbituric acid reactive substance and reduced glutathione, measured on a protein basis and fresh weight basis. Superoxide dismutase activity increased under NaCl treatment at day 7 in both samples versus the controls. In the Razaki cultivar, glutathione peroxidase activity was at maximum at day 7 under 12 mM NaCl treatment. Catalase activity was very low, and increased with increasing NaCl concentration in the Razaki cultivar and 1616C rootstock at day 7. In 1616C rootstock the nitrite level was lower than the controls within 4 days.