Hydrogen sulfide, a signaling molecule in plant stress responses

Abstract

Gaseous molecules, such as hydrogen sulfide (H₂S) and nitric oxide (NO), are crucial players in cellular and (patho)physiological processes in biological systems. The biological functions of these gaseous molecules, which were first discovered and identified as gasotransmitters in animals, have received unprecedented attention from plant scientists in recent decades. Researchers have arrived at the consensus that H₂S is synthesized endogenously and serves as a signaling molecule throughout the plant life cycle. However, the mechanisms of H₂S action in redox biology is still largely unexplored. This review highlights what we currently know about the characteristics and biosynthesis of H₂S in plants. Additionally, we summarize the role of H₂S in plant resistance to abiotic stress. Moreover, we propose and discuss possible redox-dependent mechanisms by which H₂S regulates plant physiology.