Hydrogen gas: a potential novel tool to enhance abiotic stress tolerance in plant

• Hydrogen gas (H2) is a unique gaseous molecular messenger influencing plant physiological processes. • H2 enhances stress tolerance via multiple ways like strengthening antioxidant defense. • Discusses H2 interactions with other signaling molecules for stress tolerance. • Focuses on potential mechanisms of H2 action under adversity stress. Hydrogen gas (H 2 ) is a unique gaseous molecular messenger, and it influences several physiological processes in plants. In the review, we cover current developments in the study of the role of H 2 in plant response to abiotic stresses. Overall, H 2 can enhance environmental stress tolerance by strengthening antioxidant defense mechanisms, increasing photosynthetic capacity, re-establishing ion homeostasis, preserving nutritional homeostasis, and regulating flavonoid pathways. In addition, we discuss the interactions of H 2 with other signaling molecules in enhancing plant abiotic stress tolerance. Furthermore, this review is focused on discussing the potential mechanisms of H 2 action in plants under adversity stress. Nevertheless, there is little evidence regarding the molecular mechanisms mediated by H 2 under abiotic stress. More studies are required to advance our understanding of the potential applications of H 2 in response to abiotic stresses in plants.