Status of Antioxidative System in Maize Leaves Exposed To Peg-6000Author(s): Meeta Jain*, Swati Tiwary, Rajendra Bapna, Sangeeta Jain
Antioxidative responses in Zea mays leaves subjected to different osmotic potentials induced by PEG 6000 were investigated. Drought stress significantly enhanced the Malondialdehyde (MDA) content in leaf segments obtained from light grown maize plants. The H2O2 content decreased gradually with increasing concentration of PEG 6000, while there was a marked augmentation in catalase activity involved in decomposition of H2O2 . Guaiacol peroxidase and Superoxide Dismutase (SOD) activities also increased prominently by PEG induced drought stress. Ascorbate Peroxidase (APX) and Glutathione Reductase (GR) activities enhanced in a concentration dependent manner with the increased supplementation of PEG. Further, higher total ascorbate content and lower glutathione content was detected in leaf tissue exposed to PEG. It is suggested that in order to overcome the oxidative stress generated by the supply of PEG-6000, level of antioxidant ascorbate increased along with antioxidative enzymes, SOD, catalase and Gu-POX in light grown leaf segments. Further, increased activities of APX and GR indicate operation of ascorbate - glutathione cycle at high rates under the conditions of water deficit.