identifier: traitmech:000676
label: cyanobacterial multiseriate trichome formation
definition: A morphological phenotype in which a cyanobacterium develops a trichome
  containing more than one adjacent row of cells through cell division in multiple
  planes.
definition_source: DOI:10.1002/2211-5463.13016
trait_category: MORPHOLOGY
term_kind: CLASS
mapping_status: PROPOSED
parent_traits:
- METPO:1000059
evidence:
- reference: DOI:10.1002/2211-5463.13016
  snippet: cells divide at a right angle to the longitudinal filament axis and in
    planes parallel or oblique to the primary trichomes.
  notes: Springstein et al. (2020), Introduction; primary full-text XML https://www.ebi.ac.uk/europepmc/webservices/rest/PMC7714070/fullTextXML
    and actual Figure 2E inspected. The text links multiplanar division to multiseriate
    Chlorogloeopsis fritschii PCC 6912 trichomes, contrasting them with lateral Fischerella
    branches. Figure 2E shows a mature multiseriate stage, distinct from the linear
    hormogonium in 2D. Methods describe stock cultures at 37 degrees C in BG11 or
    BG11(0), with an 18:6 light-dark cycle; Van-FL microscopy follows a one-hour stain.
    This morphology evidence is not the separate FtsZ-overexpression phenotype.
- reference: DOI:10.1186/s12862-017-1053-5
  snippet: When grown in BG11, C. fritschii developed multi-seriate filaments.
  notes: Koch et al. (2017), Additional file 1, Figure S6A caption, PDF page 8; actual
    S6 and S1 images and supplementary text pages 1-2 inspected at https://media.springernature.com/original/springer-static/esm/art%3A10.1186%2Fs12862-017-1053-5/MediaObjects/12862_2017_1053_MOESM1_ESM.pdf.
    S6B instead shows aseriate clusters with 100 mM NaCl; loose clusters are not automatically
    multiseriate trichomes. Main Results and S1 report salt-associated multiseriate
    main filaments in Fischerella, showing that branching and multiseriality can coexist
    and that salt responses are taxon-specific. Transcript correlations do not establish
    a universal mechanism.
- reference: DOI:10.3126/on.v14i1.16445
  snippet: The present algal taxon exhibited vertical and horizontal divisions of
    cells and has a tendency to form filamentous structure.
  notes: Halder (2016), Results and discussion, article page 95, https://www.nepjol.info/index.php/ON/article/view/16445/13360.
    Methods, description and actual Figure 1A-D on page 96 inspected. The description
    records cell rows and Conclusions describe progression from uniseriate to multiseriate
    filaments. This is light-microscopy-based identification of field material, not
    sequence-confirmed identity, a controlled time-lapse lineage experiment, or proof
    of the paper's suggested fertilizer benefit.
canonical_examples:
- taxon_id: NCBITaxon:1124
  taxon_label: Chlorogloeopsis fritschii
  reference: DOI:10.3126/on.v14i1.16445
  note: Restricted to the multiseriate stage described for field collection NH-1260,
    sampled on 18 March 2013 in a rice field at Balagarh, Hooghly, West Bengal, India.
    Provenance and herbarium deposition are reported in Methods/Results at https://www.nepjol.info/index.php/ON/article/view/16445/13360.
    The source identifies the material morphologically; it is not assigned a PCC strain
    identity. Live NCBI efetch https://eutils.ncbi.nlm.nih.gov/entrez/eutils/efetch.fcgi?db=taxonomy&id=1124
    confirms the current species name and rank species, not an NH-1260 accession or
    independent phenotype evidence. Not every cell, stage or condition is multiseriate.
discussions:
- discussion_id: multiseriate-trichome-scope
  prompt: Review the closer multicellular morphology parent and terminology.
  kind: CURATION_TODO
  status: OPEN
  rationale: Use phenotype METPO:1000059 below quality METPO:1000188. The definition
    concerns adjacent cell rows in a trichome, including two rows, not multiple independent
    uniseriate trichomes merely bundled in a common sheath. It is not a synonym of
    branched shaped METPO:1000687, generic filament shaped morphology, hormogonium
    formation traitmech:000651, or cyanobacterial false branching traitmech:000675.
    Cell-shape parents do not unambiguously capture this multicellular organization;
    obsolete cell-arrangement terms redirect to flagellar arrangement and are unsuitable.
    Springstein's parenthetical description speaks of multiple trichomes in a row,
    whereas its division context and the other inspected sources support adjacent
    cell rows. Keep that wording distinction explicit. The qualified label does not
    cover every multiseriate algal or plant structure. No exact synonyms, xrefs, SSSOM
    mappings, mandatory branching or organism-level disjointness are asserted.
  posed_by: codex
  posed_date: '2026-10-08'
- discussion_id: multiseriate-trichome-mechanism
  prompt: Resolve native division-plane control without conflating experimental states.
  kind: KNOWLEDGE_GAP
  status: OPEN
  rationale: The cited studies distinguish natural developmental states, environment-associated
    changes and engineered protein overexpression. Do not transfer an engineered phenotype
    to a natural canonical example or infer a gene mechanism from transcript correlations.
    Neither salt exposure, a fixed row number, a persistent filament length nor a
    fitness benefit defines the whole class. No causal graph is proposed pending a
    protein-resolved native mechanism with verified accessions; mechanism is deferred,
    not claimed absent.
  posed_by: codex
  posed_date: '2026-10-08'
curation_history:
- timestamp: '2026-10-08T07:45:42Z'
  curator: codex
  action: MINTED_TRAITMECH_ID
  changes: Added cyanobacterial multiseriate trichome formation with three DOI sources,
    source-checked snippets and a qualified field example. Ignored-and-hidden main/worktree/open-PR
    checks support 000676 and v552 block 1062900-1062999. Kept branching, loose clusters,
    bundled trichomes and engineered morphotypes distinct. Existing records unchanged;
    timestamp is observed UTC.
  llm_assisted: true