# Molecular hydrogen is involved in phytohormone signaling and stress responses in plants.
> 植物における分子状水素の植物ホルモンシグナル伝達およびストレス応答への関与


## Abstract

This study examined the biological roles of molecular hydrogen (H2) in higher plants, focusing on phytohormone signaling and stress responses. In mung bean seeds exposed to phytohormones, hydrogen water (HW) application elevated antioxidant enzyme activity and altered the transcription of corresponding genes. In rice seedlings treated with HW, upregulation of phytohormone receptor genes and key signaling pathway components was detected. Endogenous H2 production, hydrogenase activity, and putative hydrogenase gene expression were all induced by abscisic acid, ethylene, jasmonic acid, salt stress, and drought stress in a mutually consistent manner. These findings indicate that H2 may contribute to stress tolerance in rice by modulating hormone-mediated signaling outputs, suggesting a broader biological role for H2 beyond its known antioxidant functions.

### Mechanism

H2 appears to upregulate phytohormone receptor genes and enhance antioxidant enzyme activity in plant tissues, with endogenous H2 production induced by stress-related hormones and abiotic stressors, suggesting H2 participates in hormone-mediated stress signaling cascades.

## Bibliographic

- **Authors**: Zeng J, Zhang MH, Sun X
- **Journal**: PLoS One
- **Year**: 2013
- **PMID**: [23951075](https://pubmed.ncbi.nlm.nih.gov/23951075/)
- **DOI**: [10.1371/journal.pone.0071038](https://doi.org/10.1371/journal.pone.0071038)
- **PMC**: [PMC3741361](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3741361/)
- **Study type**: other
- **Delivery route**: hydrogen-rich water
- **Effect reported**: positive

## Delivery context

Hydrogen-rich water is a low-risk delivery route, but the achievable systemic hydrogen dose is bounded. For clinical applications, inhalation is the most efficient route; inhalation, however, carries explosion risk, and concentration matters (empirical LFL of 10% applies to inhalation environments; high-concentration devices are documented in the Consumer Affairs Agency accident database and are not recommended).

## Safety notes

Hydrogen-rich water is a low-risk delivery route, but the achievable systemic hydrogen dose is bounded. For clinical applications, inhalation is the most efficient route; inhalation, however, carries explosion risk, and concentration matters (empirical LFL of 10% applies to inhalation environments; high-concentration devices are documented in the Consumer Affairs Agency accident database and are not recommended).

See also:
- [Inhalation concentration and LFL / UFL](https://h2-papers.org/en/safety-notes/inhalation-concentration)
- [Consumer Affairs Agency accident cases](https://h2-papers.org/en/safety-notes/accident-cases)
- [Inhalation safety threshold lineage](https://h2-papers.org/en/safety-notes/lineage)

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> **Cite as**: H2 Papers — PMID 23951075. https://h2-papers.org/en/papers/23951075
> **Source**: PubMed PMID [23951075](https://pubmed.ncbi.nlm.nih.gov/23951075/)