ALTERATIONS IN THE ACTIVITY OF ANTIOXIDATIVE ENZYMES ON THE LEAVES OF MAIZE

ABSTRACT

This study investigated the alterations in the activity of antioxidative enzymes on the leaves of maize (zea mays) planted in spent engine oil contaminated soil. Maize was grown on soil contaminated with 30ml, 50ml and 70ml of spent engine oil (WSF). The experiment lasted for 4 weeks. Data obtained were analysed using ANOVA and least significant difference (LSD) at p<0.05. The number of leaves, leaf area and leaf weight were determined at the start of every assay, while the percentage germination was evaluated at the end of every week. Results showed that the mean leaf and percentage germination of maize plant (zea mays) decreased with increasing level of contamination with spent engine oil (WSF). Antioxidants like superoxide dismutase (SOD), catalase, malonyldialdehyde (MDA), glutathioneperoxidase (GPx) in zea mays differed significantly (P<0.05) at 30ml levels from those planted in 50ml and 70ml levels of the spent engine oil (WSF) contaminated soils. The reductions in these growth characteristics measured were spent engine oil (WSF) concentration dependent and elevated activity of antioxidative enzymes can assist as important components of antioxidative defense mechanism against oxidative damage. The results of this study could be beneficial in the understanding of the role of defense system beside these parameters, also significant reduction in lipase activity of the plant was recorded and yellowish leaf coloration due to reduction in chlorophyll content were observed among the plants grown in the spent engine oil contaminated soils. Spent engine oil therefore had pronounced effects on the germination and growth of maize plant as revealed by this study. Therefore, maize plant should not be grown near or on soil contaminated with spent engine oil.