The Effect of Silicon on the Activity and Isozymes Pattern of Antioxidative Enzymes of Young Maize Roots under Zinc Stress

The aim of this work was to study the effect of silicon (Si) on the activities of some antioxidative enzymes of young maize plants treated by zinc (Zn). Zinc is an essential element for higher plants but its higher concentrations are toxic for plants. Silicon is not considered as a plants essential element but research has suggested that Si can mitigate the negative effect of various plant stresses. Two maize (Zea mays L.) hybrids, Almansa and Novania, differing in their tolerance to Zn toxicity, were grown in hydroponics and the effect of exogenous Si on the activities of superoxide dismutase (SOD), peroxidase (POX) and ascorbate peroxidase (APX) in the roots of Zn treated plants was studied. The enzymes activities were recorded by spectrophotometry and their isozymes pattern was determined by native PAGE. Silicon mitigated the activity of antioxidative enzymes (SOD, APX and POX) increased by Zn stress in hybrid Almansa but the same effect was not fully observed in hybrid Novania. Our results point out that a positive effect of Si on antioxidative response of Zn treated maize plants is probably hybrid-specific.