# Hydrogen-rich water irrigation enhances fruit quality in 'Flame Seedless' grapes by regulating chlorophyll fluorescence parameters and antioxidant activities.
> 水素水灌漑による'フレームシードレス'ブドウの果実品質向上：葉緑素蛍光パラメータと抗酸化活性への影響


## Abstract

This study examined the effects of hydrogen-rich water (HRW) irrigation at 1.0 mg/L on greenhouse-grown 'Flame Seedless' grapevines, focusing on photosynthetic pigments, chlorophyll fluorescence (ChlF) parameters, antioxidant enzyme activities, and fruit quality. HRW application elevated chlorophyll a, chlorophyll b, and carotenoid contents, while improving PSII maximum quantum efficiency (Fv/Fm) and photochemical quantum yield (ΦPSII); non-photochemical quenching (NPQ) declined, indicating enhanced photosynthetic efficiency. Activities of superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT) increased, suppressing reactive oxygen species (ROS) accumulation and maintaining ROS homeostasis in leaves. Secondary metabolites including total phenolics, flavonoids, and anthocyanins accumulated at higher levels, improving the color index of red grapes (CIRG). Fruit quality parameters also improved: total soluble solids, soluble sugars, and pH increased, while firmness and titratable acidity decreased. Berry weight and overall yield were greater than in control plants, suggesting HRW irrigation as a sustainable approach for enhancing grapevine productivity.

### Mechanism

HRW irrigation upregulates antioxidant enzymes (SOD, POD, CAT), reducing ROS accumulation and preserving PSII quantum efficiency, thereby enhancing photosynthetic performance and promoting secondary metabolite biosynthesis that contributes to improved fruit quality.

## Bibliographic

- **Authors**: Ali HSM, Zhang H, Yao D, Kun L, Zhao F, Feng J, et al.
- **Journal**: Front Plant Sci
- **Year**: 2025
- **PMID**: [41230230](https://pubmed.ncbi.nlm.nih.gov/41230230/)
- **DOI**: [10.3389/fpls.2025.1693075](https://doi.org/10.3389/fpls.2025.1693075)
- **PMC**: [PMC12602219](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12602219/)
- **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 41230230. https://h2-papers.org/en/papers/41230230
> **Source**: PubMed PMID [41230230](https://pubmed.ncbi.nlm.nih.gov/41230230/)