Abstract

In this investigation, chromium (Cr) toxicity on enzymes like peroxidase, ascorbate peroxidase and acid invertase was studied in pea seedling to evaluate the relative tolerance of the different pea varieties. Effect of Cr (0, 1.0, 2.0, 3.0 mM) on different parts of the seedling that is, cotyledon, plumule and radicle were studied separately to have a comparative study of the enzyme activity in these parts of the plants and its varieties. Acid invertase activity in cotyledons of Arkel was not affected significantly by chromium but increased in Rachna and HFP-8712. Chromium decreased acid invertase activity in radicle and plumule. Chromium treatment increased peroxidase activity in all component of seedling and found to be highest in untreated cotyledons of Arkel. Ascorbate peroxidase activity in the radicle and plumule was higher in Rachna. Enzyme activity decreased significantly with the increasing chromium treatment in cotyledons of Arkel while converse was true with regard to HFP-8712. These results indicate that Rachna is more tolerant followed by HFP-8712 and Arkel.

Key words: Chromium toxicity, peroxidase, ascorbate peroxidise, acid invertase, Pisum sativum.

Abbreviation

Abbreviations: ROS, Reactive oxygen species; MTS, metallothioneins; POX, peroxidase; CAT, catalase; GPX,guaiacol peroxidise; GR, glutathione reductase; APX, ascorbate peroxidise; SOD, superoxide dismutase; Mn-SOD, Mn-superoxide dismutase.