The Effect of Sodium Hydrosulfite Pretreatment on the Reduction of the Stress Caused by Copper Toxicity in Soybean (Glycine max L.)

Although copper is an essential element for cell-based processes, in high concentrations, it is toxic for plants. Hydrogen sulfide is one of the most important signaling molecules that is involved in many processes of plant stress resistance. In order to investigate the effect of Sodium hydrosulfide pretreatment on mitigating copper damages in soybean, a factorial experiment in a completely randomized design with three replications was conducted in the research laboratory of Kerman University of Shahid Bahonar in 2015. The experiment included two factors: the use of Sodium hydrosulfide (i.e., the presence or absence of sodium hydrosulfide) and different concentrations of CuSO4 (i.e., 0, 100, & 200 μM). The results showed that an increase in copper concentration in the nutrient solution reduced the fresh weight and Chlorophyll content and increased MDA, proline, and hydrogen peroxide in soybean plants. The pretreatment of plants with Sodium hydrosulfide caused an increase in the fresh weight, the amount of Chlorophyll, soluble sugar, and the reduced glutathione and a decrease in the amount of MDA, hydrogen peroxide, and proline in soybean. Probably, hydrogen sulfide protects the plant against the oxidative damage caused by the toxicity of copper by connecting to other signaling molecules such as nitric oxide.