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

Hydrogen gas (H2), a gaseous signaling molecule, is involved in plant growth and development. This review collates emerging evidence to show that H2 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 H2 and other signaling molecules are also discussed. This paper presents the current status of H2 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 H2 signaling. The action mechanism of H2 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 H2. Therefore, the scientific and practical aspects of H2 biology are proposed for the postharvest preservation of horticultural products.