Effect of Excess and Deficient Levels of Iron and Copper on Oxidative Stress and Antioxidant Enzymes Activity in Wheat

摘要

Effect of excess and deficient levels of iron and copper were studied in wheat genotypes C 306 and Hira grown in Hoagland solution in green house. Iron deficiency resulted in loss of leaf area and total biomass. Both the genotypes showed similar pattem. In case of excess iron treatments there was slight increase in leaf area in both the genotype, whereas decrease was observed in total biomass in comparison to control plants. Copper deficiency caused loss of leaf area and total biomass in both the genotjrpes. Excess copper treatment resulted in slight increase in leaf area in C 306 than control, while Hira showed slightly lower value than control. Hydrogen peroxide and TBARS contents (lipid peroxidation) increased both under iron and copper deficiency as well as excess condition at both the stages but the increase was more than double in excess iron/copper plants in both the genotypes and at both the stages. Total SOD activity decreased in copper and iron deficient plants and slightly increased in excess copper and iron plants over deficient levels, though the level of activity was less than control plants. Excess copper and iron levels have positive effect on Cu/Zn-SOD and Fe-SOD activities at 30 DAS, while at 45 DAS the activities were more thandeficient nutrient levels, but less than control plants. Mn-SOD activity decreased under excess and deficient levels of copper, however, in excess copper plants activity was slightly higher than copper deficient plants. Excess iron has more inhibitory effect on Mn-SOD activity than deficient levels in both genotypes. Iron and copper deficiency decreased APOX and CAT activities below control levels. In case of APOX activity excess copper resulted in greater response at 30 DAS, while excess iron showed more response at 45 DAS. Excess levels of copper and iron increased CAT activity over control at both stages in 2 genottes, but the response was greater in case of iron.