TraitMech

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phototropism

traitmech:000598 · CLASS · PROPOSED

A phenotype in which growth is directionally oriented or reoriented toward or away from a light source in response to illumination.

Trait evidence (3)

  • DOI:10.1073/pnas.0600633103
    it exhibits phototropism by bending toward near-UV and blue wavelengths and away from far-UV wavelengths

    Abstract, exact-matched at Europe PMC (PMID:16537433; PMC1450208); it refers to Phycomyces blakesleeanus sporangiophore growth. The institutional full-text PDF and Figure 1A were inspected: the wild-type control bends toward white light, unlike the reduced response of madA mutants. The abstract's far-UV response is not measured in that panel. Methods identify NRRL1555 as the wild-type background and distinguish chemically mutagenized derivatives and isogenic A56. Genetic cosegregation supports madA involvement, not a complete growth-polarity pathway.

  • DOI:10.1073/pnas.0900879106
    Phototropism, growth toward light, shares many features in fungi and plants but the molecular mechanisms remain to be fully elucidated.

    Abstract, exact-matched at Europe PMC (PMID:19380729; PMC2678449). This passage describes the positive case; the Idnurm source establishes the broader directional scope. The institutional full-text PDF and Figures 2B and 4 were inspected. Phototropic responses cosegregate with madB alleles; MADA-MADB interaction assays use yeast and E. coli, not the native fungus. The Discussion leaves rapid bending mechanisms unresolved. Transcription measurements are not themselves directional-growth readouts. The supplementary strain table and figures were not accessible and were not inspected.

  • DOI:10.1128/EC.00203-13
    These strains are wild isolates, except for A56.

    Materials and Methods, Strains and growth conditions; exact contiguous raw PMC HTML text (PMID:24243797; PMC3910969). The preceding sentence includes NRRL1555 in the named strains; the following sentence distinguishes backcrossed A56. This supports natural-isolate provenance for the NRRL1555 exemplar, not an independent phototropism experiment.

Provenance

Identifier source
TraitMech local identifier
Definition source
DOI:10.1073/pnas.0600633103

Parent traits (1)

kg-microbe context

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

Canonical examples (1)

Organisms cited as exemplars of this trait. Taxon ids are NCBITaxon and link out to the NCBI record.

  • Phycomyces blakesleeanus NRRL 1555(-) NCBITaxon:763407 DOI:10.1073/pnas.0600633103 Wild-type sporangiophore growth toward white light in Figure 1A, with NRRL1555 background identified in Methods; not the madA mutants or backcrossed A56. Independent natural-isolate provenance: DOI:10.1128/EC.00203-13, Materials and Methods (https://pmc.ncbi.nlm.nih.gov/articles/PMC3910969/). Strain-level identity and exact name resolved at NCBI Taxonomy on 2026-10-04. No invariant wavelength or response direction is asserted.

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 growth, locomotion and response-direction distinctions.

CURATION TODO OPEN phototropism-growth-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 growth toward or away from light without requiring both responses in one organism or condition. It is not phototaxis (active locomotion), photokinesis (locomotion-speed change), phototrophy (energy acquisition), or light-dependent growth rate or development alone. Use phenotype rather than motile as the parent. A blue-light receptor homolog alone does not establish this phenotype. Resolve phenotype-level external equivalences separately before adding synonyms or xrefs.

Separate heterologous interaction assays from native growth control.

CURATION TODO OPEN phototropism-native-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.

Retain genetic and heterologous evidence at its measured scope. Neither a yeast interaction assay nor copurification in E. coli proves the native light-dependent interaction or the full route from photoreception to asymmetric growth. Inspect the unavailable Sanz supplement and newer primary work, and resolve eligible taxon-paired protein accessions before adding a mechanistic graph. Do not transfer plant phototropin signaling to fungi or use NONMECHANISTIC to bypass protein-grounding requirements.

Curation history

  1. · MINTED_TRAITMECH_ID · codex

    Added phototropism with two primary phenotype studies, a primary strain-provenance citation and exact snippets. Ignored-and-hidden novelty searches and structured OWL review found no exact record or METPO term. Reserved METPO:1055200 in v475. Retained both growth directions and distinguished locomotion and energy acquisition. Inspected primary figures; added NCBI-resolved natural NRRL1555 exemplar and deferred native protein-level mechanisms and unavailable supplements.