Improvement of element uptake and antioxidative defense in Brassica napus under lead stress by application of hydrogen sulfide

Abstract

Heavy metal pollution is one of the major constraints in oilseed rape (Brassica napus L.) production. In this study, protective role of hydrogen sulfide (H2S) on plant growth under lead (Pb) stress was studied in B. napus. Plants were grown hydroponically in greenhouse conditions under three levels (0, 100, and 400 μM) of Pb and three levels (0, 100 and 200 μM) of H2S donor sodium hydrosulfide. Outcomes demonstrated that Pb stress significantly reduced the plant biomass, leaf chlorophyll contents, nutrients uptake in the leaves and roots of B. napus plants. Exogenous application of H2S significantly improved the plant biomass, chlorophyll contents and concentration of macro- and micronutrients in the leaves and roots of B. napus plants under Pb-toxicity conditions. The data indicated that application of Pb alone significantly increased the reactive oxygen species (ROS) as well as malondialdehyde (MDA) in the leaves and roots of plants. Meanwhile, application of H2S decreased the production of MDA and ROS in the leaves and roots by increasing antioxidant activities under Pb stress. Moreover, this study also revealed that plants treated with H2S at different concentrations enhanced the contents of total glutathione and glutathione reduced/glutathione oxidized ratio in leaves and roots under different levels of Pb. The results depicted that H2S improved the plant biomass, uptake of nutrients in the leaves and roots of B. napus plants and enhanced the performance of antioxidant defense system due to its ameliorative potential under Pb stress conditions.