identifier: METPO:1000482 label: NaCl delta high definition: A NaCl delta phenotype with a growth-supporting NaCl breadth above approximately 8% (w/v), characteristic of extreme-euryhaline organisms. definition_source: DOI:10.1093/femsre/fuy009 trait_category: ENVIRONMENT term_kind: CLASS mapping_status: REVIEWED parent_traits: - METPO:1000335 synonyms: - synonym_text: Nad_>8 synonym_type: RELATED_SYNONYM source: metpo.owl evidence: - reference: DOI:10.1093/femsre/fuy009 snippet: salinity range notes: Osmoadaptation review supports very wide salinity-tolerance breadths as the extreme-euryhaline phenotype. - reference: DOI:10.1186/1746-1448-4-2 snippet: cope with the high salt concentrations notes: Saline-Systems review supports combined osmolyte / salt-in flexibility as the basis of very wide salinity tolerance. causal_graphs: - graph_id: nacl_delta_high_extreme_euryhaline title: NaCl-delta-high extreme-euryhaline breadth description: DOI-backed graph linking maximal osmoadaptive flexibility to NaCl growth breadths exceeding 8% (w/v). nodes: - node_id: nacl_delta_high_trait label: NaCl delta high node_type: TRAIT grounding: METPO:1000482 description: NaCl growth-supporting breadth exceeding ~8% w/v. - node_id: nacl_delta label: NaCl delta node_type: TRAIT grounding: METPO:1000335 description: Breadth of the growth-supporting NaCl range. - node_id: maximal_osmoadaptive_flexibility label: maximal osmoadaptive flexibility node_type: BIOLOGICAL_PROCESS description: Combined osmolyte-remodeling and salt-in capacity supporting growth across an extreme salinity span. - node_id: high_external_salinity label: high external salinity node_type: ENVIRONMENTAL_FACTOR description: Elevated extracellular NaCl/salt concentration imposing osmotic stress. - node_id: compatible_solute_accumulation label: compatible-solute accumulation node_type: BIOLOGICAL_PROCESS description: Intracellular accumulation of compatible solutes (e.g. glycine betaine, glutamate, proline) with rising salinity. - node_id: intracellular_k_accumulation label: intracellular K+ accumulation node_type: BIOLOGICAL_PROCESS description: Cytoplasmic accumulation of potassium ions as part of osmoadaptation. - node_id: salt_in_osmoadaptation label: salt-in osmoadaptation node_type: BIOLOGICAL_PROCESS description: Salt-in strategy maintaining high intracellular ion concentrations to balance external salinity. - node_id: acidic_proteome label: acidic proteome node_type: QUALITY description: Proteome-wide bias toward low isoelectric points, a hallmark of salt-in extreme halophily. - node_id: salinity_transition label: salinity transition across biomes node_type: ENVIRONMENTAL_FACTOR description: Evolutionary shift in environmental salinity across biomes. - node_id: proteome_reorganization label: proteome reorganization node_type: BIOLOGICAL_PROCESS description: Systematic shifts in amino-acid composition and isoelectric-point distributions accompanying salinity change. - node_id: hybrid_salt_osmoregulation label: hybrid salt-in/salt-out osmoregulation node_type: BIOLOGICAL_PROCESS description: Genomic capacity for both salt-in and salt-out strategies enabling response to variable salinity. - node_id: fluctuating_salinity_environment label: fluctuating salinity environment node_type: ENVIRONMENTAL_FACTOR description: Habitat with strongly varying salinity over time. - node_id: hypersaline_environment label: hypersaline environment node_type: ENVIRONMENTAL_FACTOR description: Environment containing >100-150 g/L salts. - node_id: halophilic_osmoadaptation label: halophilic osmoadaptation strategies node_type: BIOLOGICAL_PROCESS description: Suite of osmoadaptation strategies selected for in hypersaline conditions. edges: - subject: maximal_osmoadaptive_flexibility predicate: produces object: nacl_delta_high_trait description: Maximal osmoadaptive flexibility yields an extreme NaCl-delta breadth. evidence: - reference: DOI:10.1186/1746-1448-4-2 snippet: cope with the high salt concentrations notes: Supports maximal osmoadaptive flexibility as the basis of extreme euryhalinity. predicate_id: METPO:2000202 - subject: nacl_delta_high_trait predicate: is a object: nacl_delta description: NaCl delta high is a quantitative bin of the NaCl-delta phenotype. evidence: - reference: DOI:10.1093/femsre/fuy009 snippet: salinity range notes: Supports >8% breadth as a value within the NaCl-delta distribution. predicate_id: rdfs:subClassOf - subject: high_external_salinity predicate: increases object: compatible_solute_accumulation description: Rising external salinity increases intracellular compatible-solute content. evidence: - reference: DOI:10.1128/aem.00145-24 notes: Intracellular content of compatible solutes (glycine betaine, glutamate, proline) increases with rising salinity levels. predicate_id: RO:0002213 - subject: intracellular_k_accumulation predicate: supports object: salt_in_osmoadaptation description: Cytoplasmic K+ accumulation supports the salt-in osmoadaptation strategy. evidence: - reference: DOI:10.1038/s41559-024-02505-6 notes: Halophiles accumulate up to 4 M K+ in their cytoplasm as part of a salt-in strategy; concept-level edge across taxa. - subject: salt_in_osmoadaptation predicate: associated with object: acidic_proteome description: The salt-in strategy is associated with an acidic, low-pI proteome. evidence: - reference: DOI:10.1038/s41559-024-02505-6 notes: Proteome acidification is a hallmark of extreme halophily; median protein isoelectric points <=4.4. predicate_id: biolink:associated_with - subject: salinity_transition predicate: drives object: proteome_reorganization description: Salinity transitions across biomes drive proteome reorganization and pI shifts. evidence: - reference: DOI:10.1126/sciadv.adg2059 notes: Transitions accompanied by systematic changes in amino acid composition and isoelectric point distributions. - subject: hybrid_salt_osmoregulation predicate: supports survival in object: fluctuating_salinity_environment description: Hybrid salt-in/salt-out osmoregulation supports survival across fluctuating salinity. evidence: - reference: DOI:10.3389/frmbi.2023.1329925 notes: MAGs contain genes for both the cheaper salt-in and more expensive salt-out strategies. - subject: hypersaline_environment predicate: selects for object: halophilic_osmoadaptation description: Hypersaline environments select for halophilic osmoadaptation strategies. evidence: - reference: DOI:10.1038/s44185-024-00050-w notes: Hypersaline environments containing >100-150 g/L salts; halophiles grow at >100-150 g/L. predicate_id: METPO:2007401 curation_history: - timestamp: '2026-05-05T01:35:46.842691+00:00' curator: seed_from_metpo action: SEEDED_FROM_METPO changes: imported from data/raw/metpo.owl (CLASS) llm_assisted: false - timestamp: '2026-05-12T10:00:00-07:00' curator: claude action: CURATED_CAUSAL_GRAPH changes: Added DOI-backed definition and causal graph linking maximal osmoadaptive flexibility to the extreme-euryhaline NaCl-delta bin. llm_assisted: true - timestamp: '2026-05-20T03:35:30Z' curator: claude action: GROUND_CAUSAL_PREDICATES changes: Grounded 2 causal-edge predicate_id field(s) via mappings/predicate_grounding.tsv (METPO:2000202×1, rdfs:subClassOf×1). llm_assisted: true - timestamp: '2026-06-23T00:00:00Z' curator: claude action: ENRICH_CAUSAL_GRAPH changes: Added 6 evidence-backed generic edges (11 new nodes) from the deep-research report. llm_assisted: true - timestamp: '2026-06-24T17:21:10Z' curator: claude action: GROUND_CAUSAL_PREDICATES changes: Grounded 3 causal-edge predicate_id field(s) via mappings/predicate_grounding.tsv (RO:0002213×1, biolink:associated_with×1, METPO:2007401×1). llm_assisted: true