Effect of Artificially Supplied Chromium on Glutamine synthetase & Glutamate Synthase Activity in Leaves of Helianthus annuus L. Varieties

Release of heavy metal pollutants in soil is major threat to environment and crops. Heavy Metal pollutant, hexavalent chromium released due to anthropogenic activities effects, growth metabolism and enzymes of nitrogen metabolism in oil seed crop Helianthus annuus, after entering its to plant system. Chromium (VI) ranging from 0, 10, 20, 50, 100 and 200 mg kg soil mixture was provided to plants of three varieties of sun flower and activity of glutamine synthetase and glutamate synthase enzymes was observed in leaves of mature plants. It was observed that even at the highest concentration of chromium, the enzyme activity was reduced by only 17.65 % and 18.22 % showing that glutamine synthetase activity was showing that glutamine synthetase activity was insensitive to chromium in all these varieties of plants. For glutamate synthase enzyme, the low chromium concentration of 10 and 20 mg kg soil was favourable but high chromium IV concentration of 50, 100 and 200 mg kg soil was adversely affecting the glutamate synthase activity in all the three verities of sunflower.