Hydrogen Sulfide Modulates Salinity Stress in Common Bean Plants by Maintaining Osmolytes and Regulating Nitric Oxide Levels and Antioxidant Enzyme Expression

Abstract

The purpose of the present study is to investigate the role of hydrogen sulfide (H2S), in improving resistance to common bean salt stress. Method shows that common bean seeds were soaked in water and in two concentrations of sodium hydrosulfide (50 and 100 µM) for 8 h. After 25 days from sowing, the pots were irrigated with water and with two concentrations of NaCl (75 and 150 mM) until the end of the experiment. Results revealed that H2S relieved salt stress by decreasing growth inhibition and photosynthetic characteristics, and increasing osmolyte contents (proline and glycine betaine). Furthermore, H2S reduced oxidative damage by lowering lipid peroxidation, electrolyte leakage, and reactive oxygen species production such as hydrogen peroxide, hydroxyl radicals, and superoxide anion by increasing non-enzymatic antioxidants such as ascorbic acid and glutathione, as well as enzymatic antioxidants such as superoxide dismutase (SOD), catalase (CAT), peroxidase (POX), ascorbate peroxidase (APX), glutathione reductase (GR), and nitrate reductase (NR). Meanwhile, salt stress and H2S application increased the endogenous level of H2S, which was accompanied by an increase in nitric oxide concentration. H2S, in particular, maintained sodium (Na+) and potassium (K+) homeostasis in the presence of excess NaCl. In general, H2S effectively reduced oxidative stress in common bean plants by increasing relative expression levels of copper-zinc superoxide dismutase (Cu-ZnSOD), CAT, and glutathione S-transferase (GST). Applying H2S to common bean plants could protect them from salinity stress by maintaining the Na+/K+ balance, boosting endogenous H2S and nitric oxide levels, and preventing oxidative damage by increasing antioxidant activity.

Alleviation of Cadmium and Nickel Toxicity and Phyto-Stimulation of Tomato Plant L. by Endophytic Micrococcus luteus and Enterobacter cloacae

“…Many research findings have shown that overexpression of various antioxidant enzymes can enhance stress resistance. SOD is an important antioxidant enzyme that protects mitochondria, chloroplasts, peroxisomes, cell walls, endoplasmic reticulum, plasma membranes, and apoplast from abiotic and biotic stress because it is the first and most effective line of defense against ROS in such locations [ 96 ]. SOD activity has risen in response to Cd stress in chickpeas [ 97 ].…”

“…SOD activity has risen in response to Cd stress in chickpeas [ 97 ]. In the Haber–Weiss process, SOD is a critical antioxidant enzyme that scavenges O 2 , OH, and H 2 O 2 [ 96 ]. Thus, the tomato plant has been protected against free radical-induced membrane dysfunction by rising the action of the enzymes CAT, APX, GR, SOD, POX, and LOX.…”

“…Plant interactions with Micrococcus luteus and Enterobacter cloacae have additionally increased the production of redox components, such as reduced glutathione; they function as electron donors in enzyme-catalyzed antioxidant processes. Glutathione reductase (GR) is an important component of the ROS scavenging pathway, which contains the ascorbate-glutathione cycle [ 96 ]. The enzymatic defense antioxidant system is one mechanism that plays a critical function in preventing and stabilizing oxidative damage.…”

“…Photosynthesis, energy conservation, and carbon metabolism all need phosphate as a structural and signaling molecule [ 109 ]. As the cell’s principal osmoticum, potassium regulates cell expansion, plasma membrane potential and transport, pH value, and a variety of other catalytic activities [ 96 ]. Potassium, nitrogen, and phosphorus deficiencies cause reduced plant development, turgor loss, greater vulnerability to HM stress and infections, as well as necrosis and chlorosis [ 110 , 111 ].…”

Arbuscular Mycorrhizal Symbiosis: A Strategy for Mitigating the Impacts of Climate Change on Tropical Legume Crops

“…Salinity also causes an ionic stress attributed to sodium (Na + ) and chloride (Cl − ) ion build-up in the plant cytosol, which is toxic to the plants [ 103 ]. At the same time, other mineral ions such as K, Ca, P, and Mg are lower in legume plant cells [ 69 , 70 , 77 , 78 ], which can result in reduced photosynthetic pigments [ 70 , 75 ].…”