Abstract
Hydrogen sulfide (H2S) is a key gasotransmitter in agriculture and has been reported to increase the growth of plants in the first two weeks and to mitigate the effects of environmental stressors. GYY-4137 is widely used in these studies because it slowly releases H2S, but there is disagreement as to whether it requires enzymes to release H2S. In this article we describe the release of H2S in water without enzymes and that it releases H2S faster in organic solvents than in water or when mixed in topsoil. Furthermore, we describe the long-term effect of dosing pea, radish, and lettuce plants with GYY-4137 for up to six weeks. The effect of GYY-4137 on plant growth for six weeks was either positive or negative depending on the loading of GYY-4137 and how it was applied to plants. The addition of GYY-4137 to lettuce plants via potting mix resulted in reduced growth and death of the plants. In contrast, application of GYY-4137 to the leaves of lettuce plants increased the harvest weight of the leaves by up to 86%. Our results demonstrate that GYY-4137 can have a positive, important effect on the growth of plants but that this effect is dependent on several factors.