identifier: traitmech:000010 label: desiccation tolerant definition: An environmental tolerance in which an organism survives extreme water loss and resumes growth after rehydration (anhydrobiosis), protecting cellular macromolecules during drying. definition_source: DOI:10.3390/microorganisms10020432 trait_category: ENVIRONMENT term_kind: CLASS mapping_status: REVIEWED parent_traits: - METPO:1000059 synonyms: - synonym_text: anhydrobiotic synonym_type: RELATED_SYNONYM source: DOI:10.3390/microorganisms10020432 evidence: - reference: DOI:10.3390/microorganisms10020432 snippet: Anhydrobiosis (gr. life without water) is predominantly described as the ability of some organisms to lose all or almost all water and enter a state of suspension where the metabolism comes to a reversible standstill notes: Bacterial anhydrobiosis review supports desiccation tolerance as reversible survival of near-complete water loss. - reference: DOI:10.3390/genes14091803 snippet: Deinococcus radiodurans, a Gram-positive extremophilic bacterium, is a remarkable example of such an organism, showcasing an impressive resistance to a wide array of stressors, including ionizing radiation, desiccation, UV radiation, and oxidizing agents notes: 'Organism example: Deinococcus radiodurans is desiccation-tolerant, sharing DNA-repair machinery with its radiation tolerance.' canonical_examples: - taxon_id: NCBITaxon:54298 taxon_label: Chroococcidiopsis note: "Extremely desiccation- and radiation-tolerant cyanobacterium from deserts and endolithic habitats." reference: PMID:34122375 causal_graphs: - graph_id: desiccation_anhydrobiosis_repair title: Desiccation tolerance via anhydrobiosis and DNA-damage repair description: Evidence-backed causal sketch linking near-complete water loss to a reversible anhydrobiotic state and post-rehydration DNA-damage repair. nodes: - node_id: desiccation_tolerant_trait label: desiccation tolerant node_type: TRAIT grounding: traitmech:000010 description: Survival of extreme water loss with growth on rehydration. - node_id: water_loss label: extreme water loss node_type: ENVIRONMENTAL_FACTOR description: Near-complete loss of cellular water during drying. - node_id: anhydrobiosis_state label: anhydrobiotic state node_type: STATE description: Reversible suspended-metabolism state during dehydration. - node_id: dsb_repair label: double-strand break repair node_type: BIOLOGICAL_PROCESS grounding: GO:0006302 description: Repair of DNA double-strand breaks accumulated during drying. - node_id: oxidative_stress label: oxidative stress / ROS node_type: BIOLOGICAL_PROCESS description: Accumulation of reactive oxygen species and oxidative damage during drying. - node_id: trehalose label: trehalose node_type: CHEMICAL description: Disaccharide osmolyte accumulated as a desiccation protectant. - node_id: plasma_membrane label: plasma membrane node_type: CELLULAR_LOCALIZATION description: Phospholipid bilayer whose head groups are stabilized during dehydration. grounding: GO:0005886 - node_id: vitrification label: vitrification / glass formation node_type: BIOLOGICAL_PROCESS description: Formation of a molecular glass that reduces motion and prevents crystallization. - node_id: sod_activity label: superoxide dismutase activity node_type: MOLECULAR_FUNCTION description: Enzymatic dismutation of superoxide as an antioxidant defense. grounding: GO:0004784 - node_id: catalase_activity label: catalase activity node_type: MOLECULAR_FUNCTION description: Enzymatic detoxification of hydrogen peroxide / ROS. grounding: GO:0004096 - node_id: chaperone_activity label: heat shock protein / chaperone activity node_type: MOLECULAR_FUNCTION description: Binding of denatured proteins to prevent aggregation and aid refolding on rehydration. - node_id: protein_aggregation label: protein aggregation node_type: BIOLOGICAL_PROCESS description: Aggregation/denaturation of proteins induced by water loss. - node_id: desiccation_idps label: desiccation-related intrinsically disordered proteins node_type: GENE_OR_PROTEIN description: IDPs (e.g. LEA/CAHS) that protect cellular components during drying. edges: - subject: water_loss predicate: causes object: anhydrobiosis_state description: Extreme dehydration triggers entry into the anhydrobiotic state. evidence: - reference: DOI:10.3390/microorganisms10020432 notes: Anhydrobiosis review describes entry into a reversible metabolism-off state upon water loss. predicate_id: biolink:causes - subject: anhydrobiosis_state predicate: enables object: desiccation_tolerant_trait description: Reversible anhydrobiosis is the basis of desiccation survival. evidence: - reference: DOI:10.3390/microorganisms10020432 notes: Anhydrobiosis enables reversible survival of near-complete water loss. predicate_id: RO:0002327 - subject: dsb_repair predicate: enables object: desiccation_tolerant_trait description: Efficient DNA double-strand-break repair restores integrity on rehydration. evidence: - reference: DOI:10.3390/genes14091803 notes: Deinococcus radiodurans shares DNA-repair machinery between radiation and desiccation tolerance. predicate_id: RO:0002327 - subject: water_loss predicate: causes object: oxidative_stress description: Drying below the protective water monolayer threshold induces oxidative stress / ROS. evidence: - reference: DOI:10.1021/acs.chemrev.2c00659 notes: 'Cross-kingdom review: desiccation tolerance organisms face oxidative stress and recover after rehydration.' predicate_id: biolink:causes - subject: trehalose predicate: stabilizes object: plasma_membrane description: Trehalose interacts with phospholipid polar head groups to stabilize membranes during dehydration. evidence: - reference: DOI:10.1007/s00203-023-03683-w notes: Trehalose interacts with phospholipid polar groups to stabilize membranes. - subject: trehalose predicate: promotes object: vitrification description: Trehalose-mediated vitrification reduces molecular motion and prevents crystallization in the dry state. evidence: - reference: DOI:10.1038/s41598-023-31586-9 notes: Trehalose-mediated vitrification reduces molecular motion and prevents crystallization. predicate_id: RO:0002213 - subject: sod_activity predicate: negatively regulates object: oxidative_stress description: Superoxide dismutase is upregulated as a conserved antioxidant defense, lowering ROS. evidence: - reference: DOI:10.1021/acs.chemrev.2c00659 notes: Desiccation-tolerant organisms upregulate superoxide dismutase as conserved oxidative-stress defense. - subject: catalase_activity predicate: negatively regulates object: oxidative_stress description: Catalase detoxifies H2O2/ROS as a conserved oxidative-stress defense during drying. evidence: - reference: DOI:10.1021/acs.chemrev.2c00659 notes: Desiccation-tolerant organisms upregulate catalases for ROS detoxification. - subject: chaperone_activity predicate: negatively regulates object: protein_aggregation description: Heat shock proteins bind denatured proteins, preventing aggregation and aiding repair on rehydration. evidence: - reference: DOI:10.1007/s00203-023-03683-w notes: Heat shock proteins bind denatured proteins, preventing aggregation and aiding repair on rehydration. - subject: desiccation_idps predicate: synergizes with object: trehalose description: Desiccation-related IDPs synergize with endogenous cosolutes such as trehalose to enhance protection during drying. evidence: - reference: DOI:10.7554/eLife.97231 notes: Desiccation-related IDPs synergize with endogenous cosolutes to enhance protection during drying. curation_history: - timestamp: '2026-05-28T00:00:00Z' curator: claude action: PROPOSED_FROM_RESEARCH changes: Proposed candidate ENVIRONMENT trait (desiccation tolerance / anhydrobiosis) from literature research to fill the water-availability coverage gap. llm_assisted: true - timestamp: '2026-06-09T14:00:00Z' curator: claude action: CURATED_CAUSAL_GRAPH changes: Added evidence-backed causal graph (anhydrobiosis / DSB repair) with GO node grounding and RO/biolink predicate groundings; promoted PROPOSED to REVIEWED. llm_assisted: true - timestamp: '2026-06-23T00:00:00Z' curator: claude action: ENRICH_CAUSAL_GRAPH changes: Added 7 evidence-backed generic edges (9 new nodes) from the deep-research report. llm_assisted: true - timestamp: '2026-06-24T17:21:09Z' curator: claude action: GROUND_CAUSAL_PREDICATES changes: Grounded 2 causal-edge predicate_id field(s) via mappings/predicate_grounding.tsv (biolink:causes×1, RO:0002213×1). llm_assisted: true - timestamp: '2026-06-24T17:21:16Z' curator: claude action: GROUND_CAUSAL_NODES changes: Grounded 1 causal-node grounding field(s) via mappings/node_grounding.tsv (GO:0005886×1). llm_assisted: true - timestamp: '2026-06-24T17:23:30Z' curator: claude action: GROUND_CAUSAL_NODES changes: Grounded 2 causal-node grounding field(s) via mappings/node_grounding.tsv (GO:0004784×1, GO:0004096×1). llm_assisted: true