{
  "abstract": "Debneyol biosynthesis in Nicotiana is regulated by the microRNA 1919 (miR1919)–miR1919-targeted cell death factor 1 (MCD1) module, but the mechanisms linking enzyme association to defence-metabolite output remain incompletely resolved. Although MCD1-dependent protein association and catalytic effects have been demonstrated, direct preferential transfer of 5-epi-aristolochene (5-EA) has not. This critical narrative review addresses this evidential gap by distinguishing biochemical pathway reconstruction, protein-interaction assays, enzyme kinetics, transcript responses, metabolite profiles and infection phenotypes, and compares their inferential scope with independent plant metabolic systems. Farnesyl diphosphate is converted via 5-EA and its epoxide to debneyol. In yeast microsomes, MCD1 increased the reported maximum reaction velocity of 5-EA epoxidase (EAE) from 18.07 to 30.24 nM s−1, whereas a separate coupled-enzyme assay produced approximately threefold more epoxide. Plant experiments also revealed altered debneyol-to-capsidiol ratios, transcript abundance and infection responses. The novel contribution of this review is a structured appraisal of what each experimental approach establishes and where competing explanations remain unresolved. Direct substrate channelling, transcription-independent branch selection and specific allosteric mechanisms remain unresolved; controlled intermediate-tracing, quantitative interaction and enzyme-abundance studies are needed to discriminate among them.",
  "abstract_shown": true,
  "affiliations": [
    "Department of Biochemistry and Microbiology, Faculty of Biology and Biotechnology, Warsaw University of Life Sciences—SGGW, Nowoursynowska 159, 02-776 Warsaw, Poland"
  ],
  "article_type": null,
  "arxiv": null,
  "author_total": 1,
  "authors": [
    {
      "affs": [
        0
      ],
      "name": "Mateusz Labudda",
      "orcid": "0000-0001-8014-1644"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/bsd82xr6hpgbk.bib",
  "cited_by": 0,
  "doi": "10.3390/ijms27219951",
  "fulltext_url": null,
  "id": "bsd82xr6hpgbk",
  "issns": [
    "1422-0067"
  ],
  "landing_url": "https://www.mdpi.com/1422-0067/27/21/9951",
  "language": null,
  "licence": "CC-BY-4.0",
  "licence_label": "CC BY 4.0",
  "licence_source": "article",
  "licence_url": "https://creativecommons.org/licenses/by/4.0/",
  "metadata_licence": null,
  "native_subjects": [],
  "openalex": null,
  "pdf_url": null,
  "pmcid": null,
  "pmid": null,
  "published": "2026-11-06",
  "publisher": "MDPI AG",
  "ris": "https://research.draconitic.com/paper/bsd82xr6hpgbk.ris",
  "sources": [
    {
      "first_seen": "2026-11-07T00:21:12Z",
      "native_id": "10.3390/ijms27219951",
      "source": "crossref",
      "url": "https://www.mdpi.com/1422-0067/27/21/9951"
    }
  ],
  "subjects": [
    {
      "field": "biochemistry",
      "origin": "issn:1422-0067",
      "subfield": "general"
    }
  ],
  "title": "miR1919–MCD1 Regulation of Debneyol Biosynthesis in Nicotiana: Enzyme Organisation, Catalytic Evidence and the Limits of Substrate Channelling",
  "title_text": "miR1919–MCD1 Regulation of Debneyol Biosynthesis in Nicotiana: Enzyme Organisation, Catalytic Evidence and the Limits of Substrate Channelling",
  "type": "peer-reviewed",
  "updated_at": "2026-11-08T00:22:24Z",
  "url": "https://research.draconitic.com/paper/bsd82xr6hpgbk",
  "venue": "International Journal of Molecular Sciences",
  "versions": []
}