identifier: traitmech:000083
label: spore germination
definition: The physiological process by which a dormant spore exits dormancy and
  resumes vegetative growth in response to germinant signals, including release of
  dipicolinic acid and rehydration of the spore core.
definition_source: DOI:10.1016/j.mib.2003.10.001
trait_category: PHYSIOLOGY
term_kind: CLASS
mapping_status: REVIEWED
parent_traits:
- METPO:1000059
synonyms:
- synonym_text: germination
  synonym_type: RELATED_SYNONYM
  source: DOI:10.1016/j.mib.2003.10.001
evidence:
- reference: DOI:10.1016/j.mib.2003.10.001
  notes: Setlow reviews spore germination, in which nutrient germinants trigger dipicolinic-acid
    release and core rehydration to resume growth.
- reference: DOI:10.1038/nrmicro2504
  notes: Lennon & Jones frame germination as resuscitation from the dormant seed-bank
    state.
canonical_examples:
- taxon_id: NCBITaxon:1423
  taxon_label: Bacillus subtilis
  note: "Model for endospore germination (germinant receptors, cortex hydrolysis; strain 168)."
  reference: PMID:39772627
causal_graphs:
- graph_id: spore_germination_germinant_trigger
  title: Germinant-triggered spore germination
  description: Evidence-backed causal sketch linking germinant signals to exit from
    spore dormancy and resumption of growth.
  nodes:
  - node_id: spore_germination_trait
    label: spore germination
    node_type: TRAIT
    grounding: traitmech:000083
    description: Capacity of a dormant spore to resume growth.
  - node_id: germinant
    label: germinant
    node_type: CHEMICAL
    description: Nutrient signal that triggers germination.
  - node_id: spore_germination_process
    label: spore germination
    node_type: BIOLOGICAL_PROCESS
    grounding: GO:0009847
    description: Dipicolinic-acid release and core rehydration.
  - node_id: cadpa_release
    label: CaDPA release from spore core
    node_type: BIOLOGICAL_PROCESS
    description: SpoVA-mediated efflux of calcium dipicolinate (CaDPA) from the dormant
      spore core during germination.
  - node_id: cortex_hydrolysis
    label: cortex peptidoglycan hydrolysis
    node_type: BIOLOGICAL_PROCESS
    description: Degradation of the spore cortex peptidoglycan by germination-specific
      lytic enzymes.
  - node_id: core_rehydration_outgrowth
    label: core rehydration and outgrowth
    node_type: BIOLOGICAL_PROCESS
    description: Full expansion and rehydration of the spore core enabling resumption
      of metabolism and initiation of outgrowth.
  edges:
  - subject: germinant
    predicate: causes
    object: spore_germination_process
    description: Germinant binding triggers the germination process.
    evidence:
    - reference: DOI:10.1016/j.mib.2003.10.001
      notes: Setlow reviews germinant-triggered spore germination.
    predicate_id: biolink:causes
  - subject: spore_germination_process
    predicate: enables
    object: spore_germination_trait
    description: The germination process realizes the spore-germination trait.
    evidence:
    - reference: DOI:10.1038/nrmicro2504
      notes: Lennon & Jones frame germination as resuscitation from dormancy.
    predicate_id: RO:0002327
  - subject: spore_germination_process
    predicate: causes
    object: cadpa_release
    description: The germination process drives SpoVA-mediated release of calcium
      dipicolinate from the spore core.
    evidence:
    - reference: DOI:10.1126/science.adg9829
      notes: Ion release during germination drives expulsion of dipicolinic acid (CaDPA)
        through the SpoVA transport complex.
    predicate_id: biolink:causes
  - subject: cadpa_release
    predicate: activates
    object: cortex_hydrolysis
    description: Released CaDPA acts as a signal activating germination-specific cortex-lytic
      enzymes to begin cortex degradation.
    evidence:
    - reference: DOI:10.1128/mbio.02220-23
      notes: Ca-DPA release acts as a signal for a germination-specific cortex-lytic
        enzyme to begin cortex degradation.
    predicate_id: RO:0002213
  - subject: cortex_hydrolysis
    predicate: causes
    object: core_rehydration_outgrowth
    description: Once the cortex is hydrolyzed, the core can fully expand and rehydrate,
      enabling outgrowth.
    evidence:
    - reference: DOI:10.1128/mbio.02220-23
      notes: Once the cortex is hydrolyzed, the core can fully expand and rehydrate,
        allowing full metabolic capabilities and initiation of outgrowth; broadly
        supported across endospore formers.
    predicate_id: biolink:causes
  - subject: core_rehydration_outgrowth
    predicate: enables
    object: spore_germination_trait
    description: Core rehydration and outgrowth complete realization of the spore-germination
      trait.
    evidence:
    - reference: DOI:10.1128/mbio.02220-23
      notes: Core rehydration following cortex hydrolysis allows full metabolic capabilities
        and initiation of outgrowth, completing germination.
    predicate_id: RO:0002327
curation_history:
- timestamp: '2026-06-04T00:00:00Z'
  curator: claude
  action: PROPOSED_FROM_RESEARCH
  changes: Proposed candidate PHYSIOLOGY trait (spore germination), the physiological
    exit from spore dormancy; complements the morphological sporulation/spore-forming
    traits.
  llm_assisted: true
- timestamp: '2026-06-08T13:00:00Z'
  curator: claude
  action: CURATED_CAUSAL_GRAPH
  changes: Added evidence-backed causal graph (germinant-triggered germination) with
    GO node grounding and biolink/RO predicate groundings; promoted PROPOSED to REVIEWED.
  llm_assisted: true
- timestamp: '2026-06-23T00:00:00Z'
  curator: claude
  action: ENRICH_CAUSAL_GRAPH
  changes: Added 4 evidence-backed generic edges (3 new nodes) from the deep-research
    report, extending the downstream germination cascade (CaDPA release -> cortex
    hydrolysis -> core rehydration/outgrowth -> trait).
  llm_assisted: true
- timestamp: '2026-06-24T17:21:15Z'
  curator: claude
  action: GROUND_CAUSAL_PREDICATES
  changes: Grounded 4 causal-edge predicate_id field(s) via mappings/predicate_grounding.tsv
    (biolink:causes×2, RO:0002213×1, RO:0002327×1).
  llm_assisted: true