Oxidative stress caused by Basagran® herbicide is altered by salicylic acid treatments in peanut plants.

The present work was to study a protective role of salicylic acid (SA) on oxidative stress caused by Basagran^® herbicide application. Two peanut cultivars (Arachis hypogaea cv. Giza 5 and Giza 6) with different sensitivities to the herbicide were monitored for their antioxidant responses to Basagran^® and/or SA treatments. Two weeks after treatment, Basagran^® lowered leaf pigments (Chlorophyll a, Chlorophyll b and total Carotenoids) but increased hydrogen peroxide (H₂O₂) and malondialdehyde (MDA) contents indicating occurrence of lipid peroxidation and oxidative stress. Salicylic acid applied prior to low dose Basagran^® lowered H₂O₂ and MDA contents in both G5 and G6. Except for SOD which is highly stimulated, POD, CAT and APX activities showed slight changes compared to control in leaves treated with Basagran^® ± SA. The extracts tested by DPPH showed increase in total antioxidant activity by 4%-7% in SA + Basagran^® treated leaves compared to control. The increased total antioxidant activity was related to the accumulation of amounts of phenolics as a protective action stimulated by SA. Alterations of antioxidant enzymatic system, accumulation of phenolics, increasing the total antioxidant activity by SA provide an evidence of protective action of SA in Basagran^® detoxification.