TraitMech

TraitMech › PHYSIOLOGY

rheotropism

traitmech:000600 · CLASS · PROPOSED

A phenotype in which growth is directionally oriented or reoriented in response to fluid flow.

Trait evidence (3)

  • DOI:10.1016/S0006-3495(65)86719-4
    Sparsely sowed, hence independent Botrytis spores, which are fixed to the wall of a laminar flow chamber, tend to germinate downstream.

    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.

  • DOI:10.1016/S0168-1656(97)00147-8
    Hyphal tips quickly reoriented towards the upstream of the flowing medium and became aligned parallel to the flow axis as they grew larger.

    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.

  • DOI:10.1007/BF00397538
    When the spph was placed in a laminar flow of air, it grew into the wind within 2-4 min.

    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.

Provenance

Identifier source
TraitMech local identifier
Definition source
DOI:10.1016/S0006-3495(65)86719-4

Parent traits (1)

kg-microbe context

No kg-microbe node embedding matched this record in the 2026-04-25 deepwalk.

Discussions and Knowledge Gaps (2)

Open questions attached to this trait. Seeded by just knowledge-gap-scan and curated; see the corpus-wide index.

Keep flow-directed growth distinct from swimming and passive transport.

CURATION TODO OPEN rheotropism-growth-flow-and-direction-boundaries · raised by codex · 2026-10-04

Not yet attached to a section of this record — a curator sets attaches_to (e.g. causal_graphs#some_edge) so the gap shows beside the mechanism it concerns.

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.

Resolve strain provenance and discriminate mechanical from chemical cues.

CURATION TODO OPEN rheotropism-native-mechanism-and-exemplars · raised by codex · 2026-10-04

Not yet attached to a section of this record — a curator sets attaches_to (e.g. causal_graphs#some_edge) so the gap shows beside the mechanism it concerns.

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.

Curation history

  1. · MINTED_TRAITMECH_ID · codex

    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.