As a gaseous molecule, hydrogen sulfide (H2S) has been recently found to be involved in plant responses to multiple abiotic stress. In this study, salt (150 and 300 mM NaCl), osmotic (15% and 30% PEG6000) and cold (4 °C) stress treatments induced accumulation of endogenous H2S level, indicating that H2S might play a role in bermudagrass responses to salt, osmotic and cold stresses. Exogenous application of H2S donor (sodium hydrosulfide, NaHS) conferred improved salt, osmotic and freezing stress tolerances in bermudagrass, which were evidenced by decreased electrolyte leakage and increased survival rate under stress conditions. Additionally, NaHS treatment alleviated the reactive oxygen species (ROS) burst and cell damage induced by abiotic stress, via modulating metabolisms of several antioxidant enzymes [catalase (CAT), peroxidase (POD) and GR (glutathione reductase)] and non-enzymatic glutathione antioxidant pool and redox state. Moreover, exogenous NaHS treatment led to accumulation of osmolytes (proline, sucrose and soluble total sugars) in stressed bermudagrass plants. Taken together, all these data indicated the protective roles of H2S in bermudagrass responses to salt, osmotic and freezing stresses, via activation of the antioxidant response and osmolyte accumulation. These findings might be applicable to grass and crop engineering to improve abiotic stress tolerance.
Keywords: ABA; Abiotic stress; Antioxidant; Bermudagrass; CAT; DW; EL; FW; GR; GSH; GSSG; H(2); H(2)O(2); H(2)S; Hydrogen sulfide; MDA; NO; NaHS; Osmolyte; POD; ROS; Reactive oxygen species; SOD; abscisic acid; catalase; dry weight; electrolyte leakage; fresh weight; glutathione reductase; hydrogen gas; hydrogen peroxide; hydrogen sulfide; malondialdehyde; nitric oxide; oxidized glutathione; peroxidase; reactive oxygen species; reduced glutathione; sodium hydrosulfide; superoxide dismutase; superoxide radical.
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