TraitMech

TraitMech › PHYSIOLOGY

chemotropism

traitmech:000597 · CLASS · PROPOSED

A phenotype in which polarized growth is directionally biased in response to a spatial chemical gradient.

Trait evidence (2)

  • DOI:10.1371/journal.pbio.3002726
    Notably, many hyphae changed direction near the boundary, opting to remain in the pH 6.5 layer (Fig 3B).

    Results, Chemotropism to low pH; exact span in Europe PMC full text PMC11288418 (PMID:39078817), published 2024-07-30. The compared layers are pH 6.5 and 8. Figure 3 was visually inspected: tip trajectories support directional growth, not only greater biomass. Main Results and the primary abstract describe lower-pH preference in these comparisons; the separate summary abstract's acidic-pH avoidance wording conflicts with them. Growth inhibition at pH 3 and carbon-source growth differences confound those comparisons. The nitrogen Results separately report negative chemotropism. S1 Table (10.1371/journal.pbio.3002726.s002), inspected as PDF text and image, lists engineered backgrounds including TH122; no natural canonical strain is inferred. Other supplements and movies were not inspected.

  • DOI:10.1038/s41598-020-67597-z
    They respond to changes in their environment by directing hyphal growth towards or away from a range of chemical stimuli.

    Introduction, first paragraph; They refers to filamentous fungi. Exact span in Europe PMC full text PMC7329813 (PMID:32612109). This supports the polarity-neutral growth definition. The first Results subsection reports directional growth of Fusarium graminearum towards methionine, while rapid growth with other tested nitrogen compounds was not significantly directional. Table 1 identifies GZ-3639 as wild type, but natural provenance and an exact NCBI identity were not independently verified. Figures and supplements were not visually inspected. The paper's receptor and infection findings are not transferred into a universal chemotropism mechanism or canonical example.

Provenance

Identifier source
TraitMech local identifier
Definition source
DOI:10.1371/journal.pbio.3002726

Parent traits (1)

Children (2)

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.

Preserve direction, growth-rate and source-summary distinctions.

CURATION TODO OPEN chemotropism-growth-and-source-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.

This class covers positive and negative chemical-gradient responses of polarized growth, not whole-cell locomotion. Use phenotype rather than motile as the parent. Neither increased biomass, faster extension nor asymmetric branching alone establishes directed growth. Keep chemotaxis, contact guidance and electric-field growth distinct. The Yamamoto summary abstract conflicts with the main Results on the pH-response direction; retain the inspected Results and Figure 3 context rather than silently harmonizing them. External equivalences and lexical variants require separate authority and scope checks.

Resolve natural strain provenance and accession-level mechanism evidence.

CURATION TODO OPEN chemotropism-strain-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.

Keep laboratory-strain observations as qualified evidence. Verify natural provenance and NCBI identities before adding canonical examples; wild-type labels and no-auxotrophy controls do not establish an unengineered strain. The Aspergillus PmaA perturbation also affects growth and acid tolerance, so it does not isolate a dedicated chemical sensor. Inspect remaining figures and supplements and resolve taxon-paired protein accessions before adding a causal graph. Do not generalize stimulus-specific perturbations into a universal pathway or use a NONMECHANISTIC graph to bypass missing molecular evidence.

Curation history

  1. · MINTED_TRAITMECH_ID · codex

    Added chemotropism with two primary DOI citations and exact full-text snippets. Ignored-and-hidden novelty searches and structured OWL review found no exact record or METPO term. Reserved METPO:1055100 in v474. Distinguished polarized growth from locomotion and growth-rate changes; retained both gradient directions and documented conflicting summary wording. Inspected Aspergillus Figure 3 and S1 strain table. Deferred natural canonical examples and accession-level causal mechanisms.

  2. · CORRECT_EVIDENCE_SNIPPET · codex

    Raw JATS matching caught a dropped figure pointer in the uncommitted Yamamoto draft quote. Restored (Fig 3B) before the sentence-ending period to preserve the contiguous source span.