Hydrogen Sulfide Inhibits Cadmium-Induced Cell Death of Cucumber Seedling Root Tips by Protecting Mitochondrial Physiological Function

Hydrogen sulfide (H2S) can alleviate Cd-induced cell death, but the molecular mechanisms are not clear. To shed light on these mechanisms, cell death induced by 200 μM cadmium chloride in cucumber seedlings root tips was used as a model system. Here, we report that the negative effect of Cd stress in mitochondrial physiological functions include changes in cytochrome c/a, mitochondrial membrane permeability transition pores, and adenosine triphosphatase (ATPase). Moreover, Cd stress led to the release of mitochondrial Ca2+ into the cytosol. Exogenous application of sodium hydrosulfide (NaHS, a donor of H2S) inhibited cell death and maintains mitochondrial function by reducing mitochondrial hydrogen peroxide accumulation, increasing ATPase activity and down-regulating CsVDAC and CsANT expression. In summary, H2S suppressed Cd-induced cell death by improving mitochondrial physiological properties.