Glutathione Induced Antioxidant Protection Against Salinity Stress in Chickpea (Cicer arietinum L.) Plant

Abstract

A POT experiment was conducted to evaluate the possible role of foliar treatment of glutathione in enhancing the antioxidant defense system of chickpea plant. Different concentrations (0, 50, 100 and 150 mg/L) of glutathione were used; namely GHS0, GHS1, GHS2 & GHS3, respectively under different levels of seawater salinity (0.23, 3.13 and 6.25 dS/m namely S0, S1 & S2, respectively). Seawater levels, S1& S2 caused obvious increases in proline, free amino acids and total soluble sugar contents. Moreover, foliar application of glutathione caused more significant increases in the above mentioned osmoprotectant contents of chickpea plants, as compared with those of corresponding controls. In addition, irrigation of chickpea plant with different levels of diluted seawater significantly increased hydrogen peroxide and lipid peroxidation, as compared with the tap water irrigated plants. Meanwhile, treating chickpea plants with different concentrations of glutathione resulted in significant decreases in hydrogen peroxide contents and lipid peroxidation levels in the control and salinity stressed plants. The applied concentrations of glutathione also resulted in marked increases of the antioxidant enzymes ascorbate peroxidase, glutathione reductase, peroxidase and superoxide dismutase. Maximum increases in the activities of antioxidant enzymes were observed on treating plants with glutathione at 100 mg/L either under normal irrigation or salinity stressed conditions. It could be concluded that foliar spray of glutathione was effective in improving chickpea performance by reducing hydrogen peroxide free radical and by enhancing compatible osmolytes, membrane stability and antioxidant enzyme activities.