# The Involvement of Glucose in Hydrogen Gas-Medicated Adventitious Rooting in Cucumber.
> キュウリの不定根形成における水素ガスとグルコースの関与


## Abstract

This study examined the relationship between hydrogen-rich water (HRW) and glucose (Glc) in adventitious root development in cucumber. Exogenous Glc promoted adventitious rooting in a dose-dependent manner, with peak activity at 0.10 mM. The promotive effect of HRW on adventitious rooting was abolished by glucosamine (GlcN), a specific Glc inhibitor, indicating that Glc signaling is required downstream of H2. HRW elevated levels of glucose, sucrose, starch, and total sugars, as well as phosphorylated intermediates including glucose-6-phosphate, fructose-6-phosphate, and glucose-1-phosphate. Activities of sucrose-metabolizing enzymes (sucrose synthase, sucrose phosphate synthase) and glucose-metabolizing enzymes (hexokinase, pyruvate kinase, ADP-pyrophosphorylase) were all enhanced by HRW. Expression of multiple sucrose and glucose metabolism-related genes was similarly upregulated by HRW and suppressed by GlcN. These findings indicate that H2 promotes adventitious root formation through stimulation of glucose metabolic pathways.

### Mechanism

H2 upregulates sucrose and glucose metabolic enzymes (SS, SPS, HK, PK, AGPase) and their corresponding genes, elevating phosphorylated sugar intermediates and promoting glucose flux that drives adventitious root initiation in cucumber.

## Bibliographic

- **Authors**: Zhao Z, Li CY, Liu H, Yang J, Huang PC, Liao W
- **Journal**: Plants (Basel)
- **Year**: 2021 (2021-09-17)
- **PMID**: [34579469](https://pubmed.ncbi.nlm.nih.gov/34579469/)
- **DOI**: [10.3390/plants10091937](https://doi.org/10.3390/plants10091937)
- **PMC**: [PMC8469787](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8469787/)
- **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 34579469. https://h2-papers.org/en/papers/34579469
> **Source**: PubMed PMID [34579469](https://pubmed.ncbi.nlm.nih.gov/34579469/)