Effects of Exogenous Salicylic Acid on the Antioxidative System in Bean Seedling Treated with Manganese
Issam Saidi *
Department of Biology, Laboratory of Plant Physiology and Biotechnology, Faculty of Sciences of Tunis, Campus Universitaire, 1060 Tunis, Tunisia
Nasreddine Yousfi
Department of Biology, Laboratory of Plant Extrêmophiles, Biotechnology Center of Borj Cédria, BP 901, 2050 Hammam-Lif, Tunisia
Wahbi Djebali
Department of Biology, Laboratory of Plant Physiology and Biotechnology, Faculty of Sciences of Tunis, Campus Universitaire, 1060 Tunis, Tunisia
Yacine Chtourou
Department of Biology, Laboratory of Toxicology and Environmental Microbiology, Faculty of Sciences of Sfax, Tunisia
*Author to whom correspondence should be addressed.
Abstract
In the present study we investigated the role of salicylic acid (SA) in regulating Mn-induced oxidative stress in bean (Phaseolus vulgaris) leaves. Exposure of plants to 100 µM Mn inhibited biomass production and intensively increased Mn accumulation in leaves. Concomitantly, Mn significantly enhanced protein carbonyl, H2O2 content and lipid peroxidation as indicated by malondialdehyde (MDA) accumulation. SA (10, 50 and 100 µM) pretreatment alleviated the negative effect of Mn on plan growth and led to decrease in oxidative stress induced by Mn stress. Furthermore, SA enhanced the activities of catalase (CAT, EC 1.11.1.6), ascorbate peroxidase (APX, EC 1.11.1.11), but lowered that of superoxide dismutase (SOD, EC 1.15.1.1) and guaiacol peroxidase (POD, EC 1.11.1.7). The data suggest that the beneficial effect of SA could be related to avoidance of oxidative damage upon exposure to Mn thus reducing the negative consequences of oxidative stress caused by Mn toxicity.
Keywords: Manganese, salicylic acid, oxidative stress, antioxidants, Phaseolus vulgaris