# Transcriptome and Metabonomics Combined Analysis Revealed the Defense Mechanism Involved in Hydrogen-Rich Water-Regulated Cold Stress Response of.
> 水素水処理による低温ストレス応答の防御機構：トランスクリプトームとメタボノミクスの統合解析


## Abstract

Cold stress tolerance is a limiting factor in certain plant cultivation industries. This study employed combined metabolome and transcriptome profiling to investigate how 75% hydrogen-rich water (HRW) modulates plant defense responses under cold stress conditions. HRW application reduced stomatal density, enhanced photosynthetic efficiency, and improved resistance-related physiological parameters including Pn, Cond, MDA, and SOD. A total of 7,883 differentially expressed genes (DEGs) and 439 differentially expressed metabolites (DEMs) were identified, with DEGs predominantly associated with phenylpropanoid, isoflavonoid, monoterpenoid, and flavonoid biosynthesis pathways. Weighted gene co-expression network analysis (WGCNA) revealed a gene module strongly correlated with total antioxidant capacity and transpiration rate. Cold stress upregulated PAL, CHS, COMT, CCR, and AtBG1, leading to accumulation of coniferyl alcohol and eriodictyol; HRW treatment attenuated these elevations. The findings identify candidate genes for flavonoid biosynthesis relevant to improving cold tolerance via molecular breeding.

### Mechanism

Cold stress upregulates PAL, CHS, COMT, CCR, and AtBG1 expression, causing accumulation of coniferyl alcohol and eriodictyol. HRW at 75% concentration modulates phenylpropanoid and flavonoid biosynthesis pathways, attenuating these metabolite elevations and improving antioxidant capacity and photosynthetic function.

## Bibliographic

- **Authors**: Liu Y, Pan J, Ni S, Xing B, Cheng K, Peng X
- **Journal**: Front Plant Sci
- **Year**: 2022
- **PMID**: [35812920](https://pubmed.ncbi.nlm.nih.gov/35812920/)
- **DOI**: [10.3389/fpls.2022.889726](https://doi.org/10.3389/fpls.2022.889726)
- **PMC**: [PMC9260428](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9260428/)
- **Study type**: other
- **Delivery route**: hydrogen-rich water
- **Effect reported**: positive
- **H2 concentration**: 75%

## 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 35812920. https://h2-papers.org/en/papers/35812920
> **Source**: PubMed PMID [35812920](https://pubmed.ncbi.nlm.nih.gov/35812920/)