galvanotropism

traitmech:000595 · CLASS · PROPOSED

A phenotype in which growth is directionally oriented or reoriented in response to an electric field.

Trait evidence (3)

DOI:10.1128/jb.176.3.702-713.1994
Field-treated (but not control) Enterobacter cloacae and Escherichia coli cells curved rapidly toward the anode.

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.
DOI:10.1099/00221287-136-2-311
germ tubes grew unidirectionally towards the cathode for extended periods and did not deviate to a perpendicular orientation.

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.
DOI:10.1016/j.cub.2006.12.043
extending hyphae grew toward the cathode and reoriented their direction of growth when the field polarity was reversed

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.

Provenance

Identifier source: TraitMech local identifier
Definition source: DOI:10.1128/jb.176.3.702-713.1994

Parent traits (1)

phenotype METPO:1000059

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 directional growth separate from movement and passive field effects.

CURATION TODO OPEN galvanotropism-growth-and-field-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.

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.

Resolve natural-strain evidence and distinguish emergence from maintenance.

CURATION TODO OPEN galvanotropism-stage-and-mechanism-grounding · 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 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.

Curation history

2026-10-04T11:09:43Z · MINTED_TRAITMECH_ID · codex
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.