TraitMech

TraitMech › MORPHOLOGY

fungal adhesive-knob trap formation

traitmech:000679 · CLASS · PROPOSED

A morphological phenotype in which a fungus forms unicellular knobs at hyphal apices that serve as adhesive nematode traps.

Trait evidence (2)

  • DOI:10.1128/AEM.01390-13
    The trap of M. haptotylum consists of a unicellular structure called a knob that develops at the apex of a hypha.

    Andersson et al. (2013), scientific Abstract; primary publisher HTML https://journals.asm.org/doi/10.1128/AEM.01390-13. Introduction, Culture Methods, relevant Results/Discussion and Conclusion, and actual Figure 1 were inspected. CBS 200.50 formed knobs in aerated liquid culture. Figure 1 shows residual attached knobs and isolated knobs after filtration, not a capture time course. Detachment is a culture observation, not a defining requirement. Proteomic and transcript changes do not establish causal functions of individual proteins; WSC adhesion roles remain hypotheses. Supplements were not used to assert protein mechanisms.

  • DOI:10.1016/j.femsle.2005.02.027
    The adhesive knobs were produced frequently on nutritional agar plates even in the absence of challenging nematodes.

    Liu, Liu and Zhuang (2005), scientific Abstract, directly retrieved from the primary publisher https://academic.oup.com/femsle/article/245/1/99/483775 (minimal-article redirect). Abstract-only access: full Methods and figures were not retrieved. Orbilia querci material came from rotten Quercus wood in Huai-rou County, Beijing, and pure culture from ascospores. The authors report nematode capture with adhesive stalked knobs. Formation without added prey under these conditions excludes an obligatory prey-induction definition; neither medium nor stalk length is universal. The reported Dactylellina querci anamorph name is source terminology, not an independently verified current taxonomic equivalence.

Provenance

Identifier source
TraitMech local identifier
Definition source
DOI:10.1128/AEM.01390-13

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.

  • Dactylellina haptotyla CBS 200.50 NCBITaxon:1284197 DOI:10.1128/AEM.01390-13 Source-named Monacrosporium haptotylum CBS 200.50. Live NCBI https://eutils.ncbi.nlm.nih.gov/entrez/eutils/efetch.fcgi?db=taxonomy&id=1284197 resolves rank strain, the exact label Dactylellina haptotyla CBS 200.50 and the historical name. Zhou et al. (2018), DOI:10.1080/23802359.2018.1507650, body paragraph 2, directly read primary XML at https://www.ebi.ac.uk/europepmc/webservices/rest/PMC7801010/fullTextXML, reports collection from a decaying leaf in a pond at Chelsea Physic Garden, London, by M.P. Peach in 1948. That genome study is strain-provenance support, not an independent knob-formation experiment. The unperturbed natural-origin strain example is qualified by the 2013 culture conditions, not every isolate or field biocontrol efficacy.

Discussions and Knowledge Gaps (2)

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

Resolve a closer fungal trap-morphology parent.

CURATION TODO RESOLVED adhesive-knob-scope-and-parent · raised by codex · 2026-10-08

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.

Phenotype METPO:1000059 is a broad parent. Existing mycelial growth traitmech:000074 explicitly concerns bacteria; hyphal anastomosis traitmech:000605 concerns fusion. Distinguish unicellular adhesive knobs from multicellular adhesive nets, adhesive columns, nonconstricting rings and mechanically constricting rings. Auxiliary cells and appressoria have different biological roles; a generic rounded hyphal tip or nematophagous genus is not sufficient. Detachment, a particular stalk length and nematode induction are not defining requirements. Formation alone does not demonstrate adhesion or successful capture in every condition. No exact synonyms, xrefs, SSSOM equivalences or organism-level disjointness are asserted; closer hierarchy remains open.

Resolution: Added fungal nematode-trap formation traitmech:000718 as the direct broader phenotype. The existing child definition entails specialized hyphal trap differentiation. This resolves only the parent gap; the historical scope contrasts, unasserted mappings, examples and separate mechanism questions remain applicable. Formation does not guarantee immediate capture. The column cell-count question is separately OPEN. Preserve the historical phenotype axiom and add METPO:1063200 SubClassOf METPO:1067100 on upstream adoption.

Separate knob morphogenesis from adhesion and infection mechanisms.

KNOWLEDGE GAP OPEN adhesive-knob-mechanism · raised by codex · 2026-10-08

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.

Sequence features and expression correlations alone do not establish a necessary or sufficient gene effect. A protein-resolved causal graph requires perturbation and complementation evidence, relevant remaining figures and supplements, and taxon-paired accessions. Formation, adhesion, capture, penetration and digestion remain separate endpoints. No universal lectin, WSC-domain protein or signaling-gene requirement is asserted; mechanism is deferred, not claimed absent. Taxonomic membership alone does not establish this phenotype.

Curation history

  1. · MINTED_TRAITMECH_ID · codex

    Added fungal adhesive-knob trap formation with two independent primary DOI sources, contiguous snippets and a natural-origin strain example. Ignored-and-hidden main/worktree/open-PR checks support 000679 and v555 block 1063200-1063299. Distinguished abstract-only access and provenance-only support; separated morphology from sequence-derived mechanism hypotheses. Existing records unchanged. Timestamp is observed UTC.

  2. · REFINE_FUNGAL_TRAP_PARENT · codex

    Refined traitmech:000679 below fungal nematode-trap formation traitmech:000718 and resolved its temporary parent discussion by definition-based inference. Preserved child identity, definition, evidence, examples, mechanism gaps and earlier history.

Recorded curation sessions

  • · codex
    • CREATE — Add evidence-backed fungal adhesive-knob trap formation

      Created traitmech:000679 with primary DOI:10.1128/AEM.01390-13 and DOI:10.1016/j.femsle.2005.02.027, contiguous scientific-abstract snippets, and NCBITaxon:1284197 Dactylellina haptotyla CBS 200.50. ASM HTML and actual Figure 1 read; 2005 evidence is abstract-only. DOI:10.1080/23802359.2018.1507650 primary XML supports natural strain provenance, not a third phenotype replication. Kept morphology, detachment, prey induction and sequence-derived mechanism claims separate; closer parent and molecular mechanism remain open. Ignored-and-hidden whole-root and complete open-PR snapshot checks support local ID, cohort v555 and whole METPO block 1063200-1063299. Guarded writer dry-run and 20 focused tests passed; both snippets VERIFIED by the maintained live resolver. Broader validation results will be recorded in the PR. Existing trait YAMLs and protected spore_germination remain unchanged.

    Read this curation session
  • · codex
    • EDIT — Refine fungal trap morphology parent

      Refined the direct parent to traitmech:000718 and resolved only the parent-gap discussion by definition-based inference; preserved child identity, definition, evidence, examples, other mechanism gaps and previous history.

    Read this curation session