identifier: traitmech:000712
label: memory of acquired stress resistance
definition: A physiological phenotype in which a microbial cell or lineage retains
  elevated resistance to a later stress challenge after a previous inducing stress
  has been removed, through persistence of a non-genetic state.
definition_source: DOI:10.1534/genetics.112.143016
trait_category: PHYSIOLOGY
term_kind: CLASS
mapping_status: PROPOSED
parent_traits:
- METPO:1000059
evidence:
- reference: DOI:10.1534/genetics.112.143016
  snippet: resistance persisted for four to five generations after cells were removed
    from the prior salt treatment
  notes: Guan et al. 2012, PMID:22851651, PMC3454879; scientific abstract, directly
    matched in publisher HTML and source-qualified MED. The resistance endpoint is
    H2O2 survival, not faster transcriptional reactivation. Relevant Methods, Results
    and actual Figure 1 and S1/S2 were inspected. BY4741-background cells received
    0.7 M NaCl for 60 minutes, then grew in fresh stress-free YPD. Figure 1 describes
    three-to-four doublings over 360 minutes; four-to-five generations is the abstract
    statement. Methods specifies 11 peroxide doses plus control, whereas Figure 1A
    captions ten plotted doses. The normalized survival score is not a fraction of
    memory-bearing cells. S1 growth-arrest interventions and S2 engineered UCC8613
    daughter marking are separate contexts. No natural canonical exemplar is asserted.
    The publisher's formula rendering differs from MED H(2)O(2); the selected span
    matches both without changing either source. Raw data were not independently reanalyzed.
- reference: DOI:10.1371/journal.pbio.2003853
  snippet: the cells inheriting this ancestral PA displayed a significantly increased
    heat resistance compared to their isogenic, PA-free siblings.
  notes: Govers et al. 2018, PMID:30153247, PMC6112618; scientific abstract, not Author
    Summary, matched in primary XML and source-qualified MED. Relevant Results and
    Methods, actual Figure 4 and S6 were inspected. Engineered MG1655 IbpA-msfGFP
    reporters received 47 C for 15 minutes, recovered with growth, then faced 51 C
    for 7 minutes. Figure 4D compares aggregate-bearing and aggregate-free descendants;
    Figure 4C detects no improved population-average survival after pretreatment.
    Survival requires growth and division within eight hours. S6 detects no age-bin
    survival difference in this assay, not universal age independence. Reporter-induced
    clustering was separately tested in actual Figure 1, previously inspected for
    traitmech:000711; a monomeric label alone is not proof against artifacts. Synthetic
    induction experiments and their duration are not transferred to these heat-induced
    lineages. Raw data and all other memory-related figure images were not independently
    assessed.
discussions:
- discussion_id: stress-resistance-memory-scope-and-hierarchy
  prompt: Preserve persistence after stress removal and the resistance endpoint.
  kind: CURATION_TODO
  status: OPEN
  rationale: Compare matched genetic backgrounds and challenge conditions after removal
    of the inducing stress. Persistent resistance is not merely faster transcriptional
    reactivation or faster reacquisition after a second induction. A marker, aggregate,
    gene, ongoing stress response or single survival measurement alone does not establish
    this history-dependent phenotype. Cell-level or lineage-restricted protection
    need not improve population-average survival. No fixed duration, number of divisions,
    stressor identity or molecular mechanism is required. Genetic adaptation, carbon-source
    memory, cue-triggered anticipation, diversifying bet hedging, persister formation
    and unequal aggregate inheritance are not equivalent, though particular observations
    can overlap. Unqualified cellular memory, stress priming and cross-protection
    are not asserted as exact synonyms. Stress response (traitmech:000078) concerns
    sensing and mounting protection; its research report includes cross-protection
    as an output but does not establish persistence after removal. METPO:1000059 phenotype
    is the conservative parent pending hierarchy review; existing records are unchanged.
  posed_by: codex
  posed_date: '2026-10-12'
- discussion_id: stress-resistance-memory-evidence-limits
  prompt: Resolve natural strain provenance and assay-specific mechanisms before extending
    this draft.
  kind: KNOWLEDGE_GAP
  status: OPEN
  rationale: Neither a uniform species-wide phenotype nor a shared molecular mechanism
    is established. Laboratory backgrounds and engineered reporters remain qualified
    evidence, not natural canonical taxa. No causal graph, exact synonym or external
    equivalence is asserted. MED/Crossref and visible publisher notice checks on 2026-10-12
    exposed no linked correction or retraction for the retained sources; this bounded
    check does not prove notice absence. Guan's Crossref has-review relation is not
    a correction or independent experiment. The publisher HTML was directly retrieved
    through its public redirect after other endpoints failed. Source access limits
    and section-specific assay descriptions are retained rather than silently harmonized.
  posed_by: codex
  posed_date: '2026-10-12'
- discussion_id: stress-resistance-memory-metpo-identity
  prompt: Retain historical stress-response neighbors without reactivating their identifiers.
  kind: CURATION_TODO
  status: OPEN
  rationale: Pinned and current released METPO contain METPO:1000293 obsolete stress
    response and METPO:1000222 obsolete oxidative stress response, marked deprecated
    below ObsoleteClass with an OMO:0001000 reason annotation and no replacement or
    consider annotation in the inspected releases. These broader lexical neighbors
    do not define persistence after stress removal. Their historical rationale remains
    unresolved; neither is reactivated or used as an exact xref. Ignored/hidden available-file
    searches, retained historical trees, normalized trait semantics, pending PRs and
    ontology RDF found no exact memory class in the inspected scope. The pinned ontology
    is unchanged; this is not discovery exhaustion or a sequence-feature trait.
  posed_by: codex
  posed_date: '2026-10-12'
curation_history:
- timestamp: '2026-10-12T21:02:06Z'
  curator: codex
  action: MINTED_TRAITMECH_ID
  changes: Added memory of acquired stress resistance with two primary DOI references
    and directly checked snippets. Retained post-removal, resistance-endpoint, cell-versus-population
    and source-context limits. Reserved 000712, v588 and 1066500-1066599 after ignored/hidden,
    historical-tree, independent-copy and pending-PR checks. Examples and mechanism
    graph deferred; existing records unchanged. Timestamp is the observed UTC curation
    decision.
  llm_assisted: true