identifier: traitmech:000595
label: galvanotropism
definition: A phenotype in which growth is directionally oriented or reoriented in
  response to an electric field.
definition_source: DOI:10.1128/jb.176.3.702-713.1994
trait_category: PHYSIOLOGY
term_kind: CLASS
mapping_status: PROPOSED
parent_traits:
- METPO:1000059
evidence:
- reference: DOI:10.1128/jb.176.3.702-713.1994
  snippet: Field-treated (but not control) Enterobacter cloacae and Escherichia coli
    cells curved rapidly toward the anode.
  notes: Abstract, exact-matched at Europe PMC (PMID:8300526; PMCID:PMC205108); full
    text not inspected. Curvature depended on field strength and pH and reversed with
    field polarity. The authors report controls excluding passive bending and field-induced
    gradients of tropic substances in their assay. Bacillus subtilis required a higher
    field threshold. Spatial wall-growth measurements support growth asymmetry, not
    a resolved universal electrical sensor. The historical actin-absence premise is
    not adopted as current biology.
- reference: DOI:10.1099/00221287-136-2-311
  snippet: germ tubes grew unidirectionally towards the cathode for extended periods
    and did not deviate to a perpendicular orientation.
  notes: Abstract, exact-matched at Europe PMC (PMID:2182770); full text not inspected.
    Candida albicans cells were attached to polylysine-coated slides. Budding and
    germ-tube emergence sites, as well as subsequent growth, were biased toward the
    cathode. Higher fields delayed emergence and reduced extension rate; those effects
    are not themselves directional growth. Cathodal growth here does not imply one
    electrode preference for all microbial galvanotropism.
- reference: DOI:10.1016/j.cub.2006.12.043
  snippet: extending hyphae grew toward the cathode and reoriented their direction
    of growth when the field polarity was reversed
  notes: Full-text Results, Calcium Ions and CaCch1p Mediate Cathodal Germ-Tube Emergence
    (PMID:17275302; PMCID:PMC1885950), https://pmc.ncbi.nlm.nih.gov/articles/PMC1885950/.
    Exact contiguous JATS paragraph span, not an abstract quote. Main Figs. 1 and
    2 and supplemental Table S1 were inspected. The quoted response occurred even
    in low-calcium medium. Calcium depletion, channel blockers and CCH1 deletion primarily
    reduced cathodal emergence; after six hours, tip orientation could recover. Calcineurin
    perturbations affected cathodal emergence, not thigmotropism. Localized channel
    activation is a proposed model, not direct proof of a universal sensor. The supplement
    identifies CAI4/CIp10 as the isogenic control (NGY152) and lists engineered derivatives.
    These are qualified experimental backgrounds, not verified natural canonical exemplars.
discussions:
- discussion_id: galvanotropism-growth-and-field-boundaries
  prompt: Keep directional growth separate from movement and passive field effects.
  kind: CURATION_TODO
  status: OPEN
  rationale: Growth orientation is not whole-cell locomotion; the parent is phenotype,
    not motile. The existing galvanotaxis record (traitmech:000581) denotes active
    migration, and thigmotropism (traitmech:000594) denotes contact-directed polarized
    growth. Passive displacement, bending, alignment or changes in growth rate alone
    are insufficient. Do not conflate galvanotropism with electron uptake or current
    production. The bacterial anodal and fungal cathodal observations do not support
    an invariant electrode preference. A QuickGO galvanotropism search returned no
    hits on 2026-10-04; broader electric-field responses are not exact xrefs. Other
    external equivalences and electrotropism as a lexical variant require separate
    authority and scope checks.
  posed_by: codex
  posed_date: '2026-10-04'
- discussion_id: galvanotropism-stage-and-mechanism-grounding
  prompt: Resolve natural-strain evidence and distinguish emergence from maintenance.
  kind: CURATION_TODO
  status: OPEN
  rationale: The full fungal study distinguishes establishment of cathodal growth
    from maintenance of tip orientation. Do not turn its aggregate abstract claim
    into a requirement for calcium influx at every stage. Its supplemental Table S1
    and methods identify an engineered CAI4/CIp10 control and mutant or complemented
    derivatives; a wild-type label alone does not establish natural provenance. Inspect
    the older studies' full methods and resolve natural strains with NCBI identities
    before adding canonical examples. Resolve taxon-paired protein accessions and
    stage-specific causal claims before adding a mechanism graph. Do not transfer
    fungal channel dependence to bacteria or adopt the 1994 paper's historical actin-absence
    premise. A NONMECHANISTIC graph must not bypass missing protein grounding.
  posed_by: codex
  posed_date: '2026-10-04'
curation_history:
- timestamp: '2026-10-04T11:09:43Z'
  curator: codex
  action: MINTED_TRAITMECH_ID
  changes: Added galvanotropism with three primary DOI citations, two abstract snippets
    and one full-text snippet. Ignored-and-hidden novelty searches and structured
    OWL review found no exact record or METPO term. Reserved METPO:1054900 in v472.
    Distinguished directional growth from galvanotaxis and thigmotropism without requiring
    one electrode preference. Inspected Brand full text, Figs. 1 and 2 and supplement;
    kept emergence distinct from later orientation and deferred natural canonical
    examples and accession-level mechanism grounding.
  llm_assisted: true