# The GA and ABA signaling is required for hydrogen-mediated seed germination in wax gourd.
> 水素富化水によるトウガン種子発芽促進におけるGAおよびABAシグナル伝達の役割


## Abstract

This study examined how hydrogen-rich water (HRW) influences seed germination in wax gourd (Benincasa hispida) using pharmacological, physiological, and transcriptomic approaches. Application of 50% HRW significantly enhanced germination rates and reduced average germination time. HRW elevated gibberellin (GA) levels by upregulating biosynthesis-related genes (BhiGA3ox, BhiGA2ox, BhiKAO), while leaving abscisic acid (ABA) content and its biosynthesis/catabolism genes unaffected; however, expression of the ABA receptor gene BhiPYL was reduced. Blocking GA synthesis with paclobutrazol suppressed HRW-mediated germination, whereas the ABA biosynthesis inhibitor sodium tungstate restored it when ABA was exogenously applied. RNA-seq data indicated that genes involved in GA, ABA, and ethylene signal transduction collectively participate in HRW-regulated germination, suggesting that HRW modulates the GA–ABA balance through ethylene signaling to promote germination.

### Mechanism

HRW upregulates GA biosynthesis genes to increase GA levels and suppresses ABA receptor gene BhiPYL expression, thereby shifting the GA–ABA balance via ethylene signaling to promote seed germination in wax gourd.

## Bibliographic

- **Authors**: Chang J, Chen X, Jiao J, Li J, Song Z, Zhang BB
- **Journal**: BMC Plant Biol
- **Year**: 2024 (2024-06-13)
- **PMID**: [38872107](https://pubmed.ncbi.nlm.nih.gov/38872107/)
- **DOI**: [10.1186/s12870-024-05193-3](https://doi.org/10.1186/s12870-024-05193-3)
- **PMC**: [PMC11177465](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11177465/)
- **Study type**: other
- **Delivery route**: hydrogen-rich water
- **Effect reported**: positive
- **H2 concentration**: 50%

## 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 38872107. https://h2-papers.org/en/papers/38872107
> **Source**: PubMed PMID [38872107](https://pubmed.ncbi.nlm.nih.gov/38872107/)