Changes in oxidative damage, antioxidant enzyme activities and polyamine contents in leaves of grafted and non-grafted eggplant seedlings under stress by excess of calcium nitrate

The effect of 80 mmol L-1 stress by excess Of Calcium nitrate [Ca(NO3)(2)] on biomass production, oxidative damage, antioxidant enzymes activities and polyamine contents in leaves of grafted and non-grafted eggplant (Solarium melongena L) seedlings were studied, in which grafted plants were grafted oil a salinity tolerant rootstock (Solarium torvum Swartz). The results showed that oil the 15th day of treatment, the biomass production reduction of non-grafted seedlings was significantly higher than that of grafted seedlings. Under stress by excess of Ca(ND3)(2), Superoxide anion radical (O-2(center dot-)) producing rate, electrolyte leakage percentage, contents of hydrogen peroxide (H2O2) and nnalondialdehyde (MDA) of non-grafted seedlings were significantly higher than those of grafted seedlings, but activities Of Superoxide dismutase (SOD, EC 1.15.1.1), peroxidase (POD, EC 1.11.1.7), ascorbate peroxidase (APX, EC 1.11.1.11) and glutathione reductase (GR, EC 1.6.4.2) of grafted seedlings were significantly higher than those of non-grafted seedlings, moreover, contents of free, soluble conjugated and insoluble bound polyamines of grafted seedlings were significantly higher than those of non-grafted seedlings. and activities of diamine oxidase (DAO, EC 1.4.3.6) and polyamine oxidase (PAO, EC 1.5.3.3) of grafted seedlings were significantly lower than those of non-grafted seedlings. The possible roles of antioxidant enzymes and polyamines in protective mechanism Of grafted eggplant seedlings to stress by excess of Ca(NO3)(2) were discussed. (c) 2008 Elsevier B.V. All rights reserved.