identifier: traitmech:000600
label: rheotropism
definition: A phenotype in which growth is directionally oriented or reoriented in
  response to fluid flow.
definition_source: DOI:10.1016/S0006-3495(65)86719-4
trait_category: PHYSIOLOGY
term_kind: CLASS
mapping_status: PROPOSED
parent_traits:
- METPO:1000059
evidence:
- reference: DOI:10.1016/S0006-3495(65)86719-4
  snippet: Sparsely sowed, hence independent Botrytis spores, which are fixed to the
    wall of a laminar flow chamber, tend to germinate downstream.
  notes: Abstract, exact-matched at Europe PMC (PMID:19431336). The author-hosted
    full text was inspected at https://mterasaki.us/cellbio/lfjaffe/reprints/65bj2.pdf.
    Methods identify Botrytis cinerea without a strain accession. Figures 3 and 4
    (pages 322 and 324) measure downstream outgrowth orientation, not simply germination
    rate. Tables VI and VII (page 329) test viscosity and rotation confounds; these
    figures and tables were visually checked. The proposed self-emitted diffusible
    stimulator is an indirect mechanistic inference, not an identified molecule or
    receptor. Initial outgrowth localization is not evidence of later tip reorientation.
- reference: DOI:10.1016/S0168-1656(97)00147-8
  snippet: Hyphal tips quickly reoriented towards the upstream of the flowing medium
    and became aligned parallel to the flow axis as they grew larger.
  notes: Abstract, exact-matched at Europe PMC (PMID:9470224). Attached Aspergillus
    niger hyphae were tested in flowing liquid medium. Other tested fungi showed upstream
    hyphal and branch growth without polarized germ-tube emergence. The inlet/outlet
    pH and oxygen measurements do not exclude every local chemical gradient or identify
    a flow receptor. Strain identity, full text and figures were not verified; claims
    are abstract-limited.
- reference: DOI:10.1007/BF00397538
  snippet: When the spph was placed in a laminar flow of air, it grew into the wind
    within 2-4 min.
  notes: Abstract, exact-matched at Europe PMC (PMID:24258181). The sporangiophore
    (spph) of Phycomyces blakesleeanus exhibits upstream growth in air, establishing
    that this usage of rheotropism is not limited to liquid currents. Added ethylene
    did not remove the response; that result does not identify its mediator or establish
    a universal ethylene-independent mechanism. The barrier-avoidance assay is distinct
    from the wind assay. Strain identity, full text and figures were not verified;
    claims are abstract-limited.
discussions:
- discussion_id: rheotropism-growth-flow-and-direction-boundaries
  prompt: Keep flow-directed growth distinct from swimming and passive transport.
  kind: CURATION_TODO
  status: OPEN
  rationale: The class includes upstream or downstream growth in liquid or gas without
    requiring both directions or media in one organism. Rheotaxis concerns self-propelled
    movement, not growth orientation. Passive bending, advection, alignment and growth-rate
    changes alone are insufficient. Initiation of polarized growth and subsequent
    tip reorientation are different readouts. Resolve external phenotype equivalences
    and the scope of wind-response labels before adding xrefs or synonyms; do not
    split a lexical variant into another trait.
  posed_by: codex
  posed_date: '2026-10-04'
- discussion_id: rheotropism-native-mechanism-and-exemplars
  prompt: Resolve strain provenance and discriminate mechanical from chemical cues.
  kind: CURATION_TODO
  status: OPEN
  rationale: Flow can redistribute chemical signals as well as impose mechanical forces.
    Do not require a direct mechanoreceptor or transfer a mechanism across species,
    growth stages or fluid media. Inspect the remaining full texts and establish natural
    strain provenance and NCBI identity before adding canonical examples. Resolve
    native causal evidence and taxon-paired protein accessions before a mechanistic
    graph; do not use NONMECHANISTIC to bypass grounding requirements.
  posed_by: codex
  posed_date: '2026-10-04'
curation_history:
- timestamp: '2026-10-04T16:43:59Z'
  curator: codex
  action: MINTED_TRAITMECH_ID
  changes: Added polarity-neutral rheotropism with three primary fungal citations
    and exact abstract snippets. Ignored-and-hidden novelty searches and structured
    OWL review found no exact term. Reserved METPO:1055400 in v477. Inspected the
    1965 full text and orientation figures and controls; retained abstract-only access
    limits for the other studies. Deferred unresolved canonical strains and molecular
    mechanisms, and distinguished growth from rheotaxis.
  llm_assisted: true