Assessment of oxidative stress and genotoxicity in Allium cepa exposed to soils from rice fields

The present study evaluates the genotoxic potential of different soil samples collected from rice fields employing Allium cepa root chromosomal aberration assay using in situ and root dip modes of treatment. The study also involves assessment of oxidative stress by analyzing responses of certain antioxidative enzymes viz. catalase (CAT), ascorbate peroxidase (APX), glutathione reductase (GR), glutathione-S-transferase (GST), superoxide dismutase (SOD), guaicol peroxidase (POD) and dehydroascorbate reductase (DHAR) in A.cepa bulbs exposed to soils. Besides these, estimation of various physico-chemical parameters including metals was also carried out. All the parameters were shown to vary among different soil samples studied. Exposure of onion bulbs to soil samples resulted in induction of different types chromosomal aberrations (physiological and clastogenic). The activities of different antioxidative enzymes in A. cepa bulbs exposed to different soil samples was found to be higher for CAT, APX, GST, DHAR, SOD and lower for POD and GR than those observed for control bulbs.