Pre-treatment of hydrogen peroxide on photosynthetic machinery and antioxidant system in maize cultivars exposed to excess copper

In this investigation, H?O? pre-treatment were investigated on copper tolerance in maize (Zea mays L.) leaves.For this purpose, antioxidant enzyme activities (ascorbate peroxidase, catalase, guaiacol peroxidase, glutathion reductase, superoxide dismutase), malondialdehyde (MDA) content, endogenous H?O? levels were determined spectrophotometrically, the changes happened in the photosynthetic apparatus were analyzed fluorometrically; in two maize (Zea mays L.) cultivars Akpınar (sensitive) and Pegaso (tolerant).After all observations, it has been found that the copper stress has reduced the growth of the plants, increased levels of MDA, endogenous H?O? content, and antioxidant enzymes activities while it damaged to the chlorophyll fluorescence parameters. It has been reported that pre-treatment of H?O? has reduced the endogenous H?O2 content, and levels of MDA, increased antioxidant enzymes activities and ameliorated chlorophyll fluorescence parameters.As a consequence of these results, we can say that pre-treatment of H?O2 may decrease the negative effects of the copper stress by activation of antioxidant system enzymes, and defense the photosynthetic apparatuses in maize plants.