Hydrogen sulfide attenuates intracellular oxidative stress via repressing glycolate oxidase activities in Arabidopsis thaliana

Abstract

Abstract Background Hydrogen sulfide (H2S) has been proposed to exert anti-oxidative effect under many environmental stresses; however, how it influences oxidative stress remains largely unclear. Results Here, we assessed the effects of H2S on oxidative stress responses such as salicylic acid (SA)-dependent cell death, which triggered by increased H2O2 availability in Arabidopsis thaliana catalase-deficient mutants cat2 displaying around 20% wild-type catalase activity. H2S generation and its producing enzyme L-cysteine desulfhydrase (LCD/DES) were found to transient increase in response to intracellular oxidative stress. Although introducing the mutation of des1, an important LCD, into the cat2 background produced little effect, H2S fumigation not only rescued the cell death phenotype of cat2 plant, but also attenuated SA accumulation and oxidation of the glutathione pool. Unexpectedly, the activities of major components of ascorbate–glutathione pathway were less affected by the presence of H2S treatment, but decreased glycolate oxidase (GOX) in combination with accumulation of glycolate implied H2S treatment impacts the cellular redox homeostasis by repressing the GOX-catalyzed reaction likely via altering the major GOX transcript levels. Conclusions Our findings reveal a link between H2S and peroxisomal H2O2 production that has implications for the understanding of the multifaceted roles of H2S in the regulation of oxidative stress responses.