A novel hydrogen sulfide donor causes stomatal opening and reduces nitric oxide accumulation

Effects of hydrogen sulfide (H2S) on plant physiology have been previously studied, but such studies have relied on the use of NaSH as a method for supplying H2S to tissues. Now new compounds which give a less severe H2S shock and a more prolonged exposure to H2S have been developed. Here the effects of one such compound, GYY4137, has been investigated to determine its effects on stomatal closure in Arabidopsis thaliana. It was found that both NaSH and GYY4137 caused stomatal opening in the light and prevented stomatal closure in the dark. Nitric oxide (NO) has been well established as a mediator of stomatal movements and here it was found that both NaSH and GYY4137 reduced the accumulation of NO in guard cells, perhaps suggesting a mode of action for H2S in this system. GYY4137, and future related compounds, will be important tools to unravel the effects of plant exposure to H2S and to determine how H2S may fit into plant cell signalling pathways.

Research highlights
► The slow releasing hydrogen sulfide donor GYY4137 causes stomatal opening and reduces nitric oxide accumulation.
► First use of a slow releasing hydrogen sulfide compound in plants, GYY4137, originally designed for use in animals, hence not used in plants before.
► Hydrogen sulphide generated from NaSH or GYY4137 causes stomatal opening in Arabidopsis, under several conditions.
► Hydrogen sulphide generated from NaSH or GYY4137 appears to disrupt nitric oxide accumulation in plants, and as nitric oxide is an immensely important regulator of many facets of plants physiology this is significant.
► Work was a collaboration between a group who have expertise in hydrogen sulphide biology (Whiteman and Wood), a team with expertise in plant stress (Teklic and Lisjak) and a team with many years experience of nitric oxide research (Hancock, Wilson et al.).