An 8-member, Bacillus-dominated synthetic community (SynCom) assembled from a rice-duckweed agroecosystem by targeting taxa consistently shared across soil, root and shoot niches. The SynCom concurrently promotes rice growth and suppresses sheath blight caused by Rhizoctonia solani, reducing the final disease index by 70% without detectable phytotoxicity. Leave-one-member perturbations reveal a division-of-labor architecture: individual strains specialize in auxin production, siderophore-linked iron mobilization, or lipopeptide/polyketide-based antagonism, yielding complementary yet partially redundant contributions that render community performance resilient to single-member loss. 8 members total; strain-level identifiers available in supplementary data.
Taxonomy
| Taxon | Ontology ID | Functional Roles | Abundance |
|---|---|---|---|
| Bacillus sp. (auxin producer) — ontology label: Bacillus <firmicutes> | NCBITaxon:1386 · TaxonMech · TraitMech |
CROSS_FEEDER
|
N/A |
|
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| Bacillus sp. (siderophore producer) — ontology label: Bacillus <firmicutes> | NCBITaxon:1386 · TaxonMech · TraitMech |
CROSS_FEEDER
|
N/A |
|
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| Bacillus sp. (lipopeptide antagonist) — ontology label: Bacillus <firmicutes> | NCBITaxon:1386 · TaxonMech · TraitMech |
PRIMARY_DEGRADER
|
N/A |
|
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| Bacillus sp. (polyketide antagonist) — ontology label: Bacillus <firmicutes> | NCBITaxon:1386 · TaxonMech · TraitMech |
PRIMARY_DEGRADER
|
N/A |
|
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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.
Division-of-Labor Growth Promotion
The eight-member SynCom shows complementary, partly redundant metabolic contributions in member-dropout and omics comparisons. These support a division-of-labor interpretation associated with rice growth promotion. PARTIAL: specific metabolite-to-plant effects and reciprocal fitness among the bacteria are not established by those comparisons.
Metabolites: indole-3-acetic acid (CHEBI:16411 · MediaIngredientMech · CMMMech), acetoin (CHEBI:15688 · MediaIngredientMech · CMMMech)
Biological Processes:
- plant growth (GO:0040007 · PathwayMech)
PARTIAL: the complementary growth-associated metabolic pool is proposed to contribute to the complete SynCom greenhouse growth phenotype. Dropout/omics associations do not establish genetic necessity or in-plant chemical mediation.
Evidence
-
PMID:41736136 - PARTIAL (IN_VIVO)"complementary yet partially redundant contributions mapped members, metabolite pools, plant outcomes and rendered community performance resilient to single-member loss"
Antimicrobial Biocontrol of Sheath Blight
SynCom treatment suppressed R. solani sheath blight, with about 70% reduction of the final disease index in the tested greenhouse comparison. PARTIAL: lipopeptide/polyketide-associated features and dropout phenotypes suggest contributing chemistries, but the individual compounds are not established as necessary causes of this plant outcome. Antagonism is not itself proof of resource competition.
Metabolites: surfactin (CHEBI:29681 · MediaIngredientMech · CMMMech)
Biological Processes:
- defense response to fungus (GO:0050832 · PathwayMech)
PARTIAL: the antimicrobial-associated component is proposed to contribute to the complete SynCom disease-suppression phenotype; the observed plant protection is stronger evidence than the assignment of that protection to individual compounds.
Evidence
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PMID:41736136 - SUPPORT (IN_VIVO)"SynCom concurrently promoted rice growth and suppressed sheath blight caused by Rhizoctonia solani, reducing the final disease index by 70% without detectable phytotoxicity"
Concurrent Rice Growth Promotion and Sheath Blight Suppression
The complete SynCom concurrently promoted rice growth and suppressed sheath blight under the tested greenhouse conditions. Its culture metabolome contained both growth- and antimicrobial-associated features. These observations do not establish colonization facilitation, field efficacy, or an equivalent benefit from adding duckweed itself.
Metabolites: indole-3-acetic acid (CHEBI:16411 · MediaIngredientMech · CMMMech), surfactin (CHEBI:29681 · MediaIngredientMech · CMMMech)
Biological Processes:
- plant growth (GO:0040007 · PathwayMech)
- defense response to fungus (GO:0050832 · PathwayMech)
Evidence
-
PMID:41736136 - SUPPORT (IN_VIVO)"SynCom concurrently promoted rice growth and suppressed sheath blight caused by Rhizoctonia solani, reducing the final disease index by 70% without detectable phytotoxicity"
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PMID:41736136 - SUPPORT (IN_VITRO)"the complete SynCom uniquely recovered the full suite of plant-growth metabolites (e.g., indole-3-acetic acid, acetoin/2,3-butanediol) together with antimicrobial chemistries (e.g., surfactin, bacillomycin, fengycin, difficidin) "
Knowledge gaps & discussions (1)
KNOWLEDGE_GAP OPEN Which metabolic contributions causally explain the greenhouse plant benefits?
The complete primary main text supports dropout-dependent functional contributions and positive greenhouse outcomes, but not genetic necessity or in-plant chemical confirmation. Individual strain abundances during coculture were not measured; contribution scores are not abundance data. The source also conflicts about unique versus shared auxin production and about duckweed-comparison disease effects versus unmeasured agronomic outcomes. Do not resolve these by selecting a favorable sentence. No ecological mutualism, resource competition or colonization-facilitation type is assigned merely from benefit to rice. The unqualified 2,3-butanediol feature does not establish a specific stereoisomer. Canonical input taxonomy is preserved, but its four role placeholders do not resolve eight strain identities; issue1759 tracks non-graph corrections. No field efficacy or general safety is certified.
Attaches to: ecological_interactions#Division-of-Labor Growth Promotion, ecological_interactions#Antimicrobial Biocontrol of Sheath Blight, ecological_interactions#Concurrent Rice Growth Promotion and Sheath Blight Suppression
1 evidence item(s)
this study is limited to greenhouse conditions and does not yet establish genetic necessity for the proposed metabolite-to-phenotype links.
Explicit primary limitation separates plant efficacy from the proposed chemical mechanisms.
Environmental Factors
| Factor | Value | Unit |
|---|---|---|
| Host Plant | Oryza sativa (rice) | N/A |
| Co-cultivated Plant | Lemna minor (duckweed) | N/A |
| Growth Conditions | Greenhouse | N/A |
Growth Media
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