Effects of methyl jasmonate on the enzymatic antioxidant defense system in maize seedlings subjected to paraquat

Abstract

In the present study the effects of different concentrations of methyl jasmonate on the enzymatic activity of antioxidant defense system in roots and shoots of a maize cultivar (SC 704) seedlings were investigated in two parts. In the first part, the plants were pretreated with 0, 5, 10, 20, 50 and 100 μM methyl jasmonate 24 hours before PQ application as an inducer of oxidative stress agent. In the second part, the 0, 5, 10, 20, 50 and 100 μM concentrations of methyl jasmonate were used after PQ imposed oxidative stress. Subsequently, the intensity of enzymatic activities in roots and shoots were separately measured. The data showed that induction of oxidative stress by PQ with respect to increased malondialdehyde levels has been completely executed. Reducing the levels of lipid peroxidation to the control level was accomplished by increasing the activities of glutathion reductase, guaiacol peroxidase and ascorbate peroxidase through changes in concentration and time of application of methyl jasmonate in roots and shoots. In this relation, the 50 and 100 μM concentrations of methyl jasmonate could decrease the lipid peroxidation with highest efficiency and meaningfully in roots and shoots as compared with controls. © 2006 Asian Network for Scientific Information.