Biochemical and physiological response to oxidative stress in cultivated sugarcane and wild genera

Sugarcane related genera and species exhibit tolerance to a number of abiotic stresses. In the present study, oxidative stress response was compared between Saccharum sp and their related genera using physiological and biochemical parameters. A pot culture experiment was conducted using five clones of Erianthus arundinaceus and two commercial varieties of Saccharum hybrids. The oxidative stress was induced by external application of hydrogen peroxide (H2O2) at different concentrations (control, 300, 500, 1000 ppm) on 65 days—old plants for three consecutive days in a glass house. Adaptive response in sugarcane/wild genera was estimated in terms of chlorophyll fluorescence, chlorophyll stability index, proline, soluble protein, and reactive oxygen species scavenging enzyme activities like super oxide dismutase and peroxidase. Analysis of variance was performed and significance of each group was verified with three-way analysis of variance (chlorophyll fluorescence, peroxidase, superoxide dismutase, lipid peroxidation, protein and proline content) and two way analysis of variance (chlorophyll stability index,) followed by Tukey HSD (P < 0.05). Significant interaction between clones, H2O2 treatment and time interval was observed. Two clones of Erianthus sp (IJ76-389 and IK76-91) exhibited relatively higher tolerance for oxidative stress at 500 and 1000 ppm of H2O2 with 48 h of treatment. In Erianthus sp, the percentage increase in enzyme activity was significant; the clone IS76-139 showed maximum peroxidase (60.9% increase) and super oxide dismutase activity (189.3% increase). Cell membrane damage due to lipid peroxidation has increased with increase in concentration of H2O2. Drought tolerant sugarcane variety Co 99004 showed 50.5% reduction in lipid peroxidation when compared to the variety Co 86032. Based on physiological and biochemical response, the effective concentration to induce the oxidative stress was found to be 500 ppm at 48 h after treatment. © 2018, Indian Society for Plant Physiology.