The antioxidant effect of the exogenous polyamine Diethylentriamine (DETA) on the oxidative changes in young maize plants treated with different As concentrations was studied. The plants were grown in a climatic box in a Hogland-Arnon nutrient solution. Arsenic was applied as Na3As04 in concentrations 0, 2 and 5 mg dm-3 (pH 5.5).
The polyamine DETA (concentration 10-4 М) was added to the nutrient environment of some of the plants 24 hours prior to the As treatment. Five days later the lipid peroxidation level, the peroxidase activity, the growth and leaf gasexchange, and the protein and plastid pigments content were studied. The physiological analyses proved that DETA had positive effect on the As-treated maize plants by increasing the leaf gas-exchange, the plastid pigments content and soluble protein. The exogenous polyamine DETA, applied 24 hours prior to the As treatment, decreased considerably the lipid peroxidation level and the peroxidase itself in maize plants. DETA had protective effect on the As-induced oxidative stress, but in order to clarify its role as an antioxidant, more detailed and profound studies should be made.
