A mutualistic marine diatom-bacteria association between Pseudo-nitzschia multiseries and Sulfitobacter sp. SA11, mediated by auxin and tryptophan signaling. The bacterium synthesizes the auxin indole-3-acetic acid (IAA) from diatom-secreted and endogenous tryptophan, promoting diatom cell division as part of a complex nutrient exchange that also includes diatom organosulfur compounds and bacterial ammonia.
Taxonomy
| Taxon | Ontology ID | Functional Roles | Abundance |
|---|---|---|---|
| Pseudo-nitzschia multiseries | NCBITaxon:37319 · TaxonMech · TraitMech |
PRIMARY_PRODUCER
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DOMINANT |
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| Sulfitobacter sp. SA11 | NCBITaxon:1546519 · TaxonMech · TraitMech |
SYNTROPHIC_PARTNER
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ABUNDANT |
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Ecological Interactions
The graph shows only explicitly linked interaction participants. Community members without an asserted participant link are omitted; membership alone does not imply an interaction.
Tryptophan-Supported Sulfitobacter IAA Synthesis
The primary abstract reports bacterial IAA production using both diatom-derived and endogenous precursor pools. Preserve this biochemical attribution without treating the individual synthesis process as proof of reciprocal fitness benefits.
Source Taxon: Sulfitobacter sp. SA11
Target Taxon: Pseudo-nitzschia multiseries
Metabolites: indole-3-acetic acid (CHEBI:16411 · MediaIngredientMech · CMMMech), tryptophan (CHEBI:16828 · MediaIngredientMech · CMMMech)
Biological Processes:
- indole-3-acetic acid biosynthetic process (GO:0009684 · PathwayMech)
- response to auxin (GO:0009733 · PathwayMech)
- interspecies interaction (GO:0044419 · PathwayMech)
Bacterial indole-3-acetic acid secretion was the hormone signal that promoted Pseudo-nitzschia cell division.
Evidence
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PMID:26017307 - SUPPORT (IN_VITRO)"indole-3-acetic acid, synthesized by the bacterium using both diatom-secreted and endogenous tryptophan "
Auxin-Mediated Diatom Cell Division
The source reports that bacterial IAA promotes diatom cell division. Preserve the existing positive signaling finding and its direction, without making the individual response node a claim of reciprocal partner benefit.
Source Taxon: Sulfitobacter sp. SA11
Target Taxon: Pseudo-nitzschia multiseries
Metabolites: indole-3-acetic acid (CHEBI:16411 · MediaIngredientMech · CMMMech)
Biological Processes:
- response to auxin (GO:0009733 · PathwayMech)
Evidence
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PMID:26017307 - SUPPORT (IN_VITRO)"a Sulfitobacter species promotes diatom cell division via secretion of the hormone indole-3-acetic acid "
Infochemical Nutrient Exchange
The source describes signaling within a broader nutrient exchange between the partners. PARTIAL: the accessible abstract does not independently establish complete exchange fluxes or the necessity of every component for reciprocal fitness.
Participating Taxa: Pseudo-nitzschia multiseries, Sulfitobacter sp. SA11
Metabolites: indole-3-acetic acid (CHEBI:16411 · MediaIngredientMech · CMMMech), ammonia (CHEBI:16134 · MediaIngredientMech · CMMMech), tryptophan (CHEBI:16828 · MediaIngredientMech · CMMMech)
Biological Processes:
- interspecies interaction (GO:0044419 · PathwayMech)
Evidence
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PMID:26017307 - SUPPORT (IN_VITRO)"Indole-3-acetic acid and tryptophan serve as signalling molecules that are part of a complex exchange of nutrients, including diatom-excreted organosulfur molecules and bacterial-excreted ammonia "
Knowledge gaps & discussions (1)
KNOWLEDGE_GAP OPEN Which observations belong to the exact pair and which describe the broader environment?
The consortium-resolution workflow and broad coastal-prevalence nodes were removed from the pair-specific interaction graph; the environmental observation remains in environmental_factors. The three biological signal/exchange nodes and existing causal direction are retained. The fresh primary abstract and public publisher preview were read, not the full main methods or supplements. No new growth mechanism, toxin-production guidance, cultivation optimization or experimental design was added. Non-graph citation, culture and metal metadata remain #1742.
Attaches to: ecological_interactions#Tryptophan-Supported Sulfitobacter IAA Synthesis, ecological_interactions#Auxin-Mediated Diatom Cell Division, ecological_interactions#Infochemical Nutrient Exchange
2 evidence item(s)
Indole-3-acetic acid and tryptophan serve as signalling molecules that are part of a complex exchange of nutrients, including diatom-excreted organosulfur molecules and bacterial-excreted ammonia
Supports IAA and tryptophan signaling inside a broader nutrient exchange.
widespread indole-3-acetic acid production by Sulfitobacter-related bacteria, particularly in coastal environments
Supports environmental prevalence of Sulfitobacter-related bacterial IAA production.
Environmental Factors
| Factor | Value | Unit |
|---|---|---|
| Auxin signaling | widespread | N/A |
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| Nutrient exchange | bidirectional | N/A |
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Growth Media
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