The Effects of Molecular Hydrogen on Plant Physiology and Metabolism: An Overview

Abstract

Gaseous hydrogen (H2) has emerged as a molecule that has a significant influence on the growth and development of plants, particularly if they are under stress. Often research has shown the ameliorating effects of H2 during drought, in the presence of heavy metals or salt, or during UV light irradiation. Postharvest, H2 has been shown to increase the quality of fruits and vegetables during storage, and slows the senescence of flowers. In molecular terms, H2 has been shown to scavenge hydroxyl radicals and remove peroxynitrite, but not react with other reactive signalling molecules such as nitric oxide. However, not all the molecular actions of H2 have yet been unravelled. This is not a totally comprehensive review of the topic, but hopefully gives an overview of the influence of H2 on some of the molecular events in cells and how this can influence plant physiology. There is no doubt that H2 has significant effects in plants, and there is potential scope for its wide adoption throughout the agricultural sector.

Study details

Article type

Review

Disease / injury model

Plant stress models (drought, salinity, heavy metals, UV, postharvest senescence)

Dose comparison

The review notes that effects of H2 are often observed after short-term treatments, with measurements taken hours or days later, suggesting both short- and long-term effects. However, specific dose-response relationships are not systematically analyzed in this review.

Dose-dependent effect

Yes

Outcome

Positive

Findings

Molecular hydrogen (H2) has significant positive effects on plant physiology and metabolism, especially under stress conditions such as drought, salinity, heavy metals, and UV irradiation. H2 enhances antioxidant capacity, improves stress tolerance, delays senescence, and increases postharvest quality in fruits and flowers. The mechanisms involve scavenging of hydroxyl radicals, modulation of gene expression, and interaction with redox signaling pathways.