Hydrogen sulfide (H2
S) is predominantly considered as a gaseous transmitter or signaling molecule in plants. It has been known as a crucial player during various plant cellular and physiological processes and has been gaining unprecedented attention from researchers since decades. They regulate growth and plethora of plant developmental processes such as germination, senescence, defense, and maturation in plants. Owing to its gaseous state, they are effectively diffused towards different parts of the cell to counterbalance the antioxidant pools as well as providing sulfur to cells. H2
S participates actively during abiotic stresses and enhances plant tolerance towards adverse conditions by regulation of the antioxidative defense system, oxidative stress signaling, metal transport, Na+
homeostasis, etc. They also maintain H2
S-Cys-cycle during abiotic stressed conditions followed by post-translational modifications of cysteine residues. Besides their role during abiotic stresses, crosstalk of H2
S with other biomolecules such as NO and phytohormones (abscisic acid, salicylic acid, melatonin, ethylene, etc.) have also been explored in plant signaling. These processes also mediate protein post-translational modifications of cysteine residues. We have mainly highlighted all these biological functions along with proposing novel relevant issues that are required to be addressed further in the near future. Moreover, we have also proposed the possible mechanisms of H2
S actions in mediating redox-dependent mechanisms in plant physiology.