engleski

Hydrogen sulfide : Environmental factor or signalling molecule?

Hydrogen sulfide (H2S) has traditionally been thought of as a phytotoxin, having deleterious effects on the plant growth and survival. It is now recognised that plants have enzymes which generate H2S, cysteine desulfhydrase, and remove it, O-acetylserine lyase. Therefore it has been suggested that H2S is considered as a signalling molecule, alongside small reactive compounds such as hydrogen peroxide (H2O2) and nitric oxide (NO). Exposure of plants to low of H2S, for example from H2S donors, is revealing that many physiological effects are seen. H2S seems to have effects on stomatal apertures. Intracellular effects include increases in glutathione levels, alterations of enzyme activities and influences on NO and H2O2 metabolism. Work in animals has shown that H2S may have direct effects on thiol modifications of cysteine groups, work that will no doubt inform future studies in plants. It appears therefore, that instead of thinking of H2S as a phytotoxin it needs to be considered as a signalling molecule that interacts with reactive oxygen species and NO metabolism, as well as having direct effects on the activity of proteins. The future may see H2S being used to modulate plant physiology in the field or to protect crops from post-harvest spoilage.

GYY4137 ; hydrogen peroxide ; hydrogen sulfide ; NaSH ; nitric oxide ; signalling molecule

nije evidentirano