Hydrogen sulfide as a potential translational hub for crop salinity tolerance

Hydrogen sulfide (H 2 S) is widely implicated in plants' adaptive responses to salinity, regulating processes ranging from ionic homeostasis to antioxidant defense and is often described as a central signaling hub due to its interaction with core signaling pathways, such as Ca 2+ , reactive oxygen species, nitric oxide, and phytohormones. However, most evidence remains correlative and relies heavily on pharmacological interventions. This review critically examines the mechanistic gaps, causality, and specificity of H 2 S-mediated signaling in regulating salinity adaptive responses in plants. We argue that moving from phenomenological observations to causal mechanisms requires a strategic shift towards advanced genetic tools, in vivo dynamic imaging, synthetic biology, and systems-level interrogation. Addressing these challenges is essential to harness the translational potential of H 2 S signaling for improving crop resilience in saline environments.