Hydrogen gas: A new fresh keeping agent of perishable horticultural products.

Hydrogen gas (H), a gaseous signaling molecule, is involved in plant growth and development. This review collates emerging evidence to show that H regulates the postharvest senescence of horticultural products through critical biochemical processes, including the improvement of antioxidant systems, the activation of cell wall metabolism, the promotion of energy metabolism, the inhibition of ethylene biosynthesis and the regulation of bacterial communities. Additionally, the interactions between H and other signaling molecules are also discussed. This paper presents the current status of H research in terms of its biological effects and safety in postharvest products by combining the research results on the molecular mechanisms of biological effects and H signaling. The action mechanism of H for postharvest preservation is also proposed, and it reflects the complexity and diversity of the pathways involved. Furthermore, a growing body of evidence has found a large number of downstream pathways or targets for the medical effects of H. Therefore, the scientific and practical aspects of H biology are proposed for the postharvest preservation of horticultural products.