Hydrogen sulfide as a potential translational hub for crop salinity tolerance.

Hydrogen sulfide (H2S) 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 Ca2+, 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 H2S-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 H2S signaling for improving crop resilience in saline environments.