A simplified, native rhizosphere synthetic microbial community (SynCom) pairing a Pseudomonas isolate with a Rahnella isolate, assembled by a top-down design from rhizobacteria isolated from cadmium (Cd)-contaminated agricultural soil to partner with the perennial medicinal plant Artemisia argyi. The Pseudomonas-Rahnella pair shows strong Cd tolerance (~2 mM), plant growth-promotion (PGP) traits, and carbon fixation capacity, and was chosen for functional complementarity with minimal antagonism. Under Cd stress the SynCom establishes stable endophytic colonization (10-15%) rather than rhizoplane colonization, improving root biomass, Cd uptake, soil organic carbon accumulation, and essential-oil precursors, thereby coupling phytoremediation, productivity, and carbon sequestration.
Taxonomy
| Taxon | Ontology ID | Functional Roles | Abundance |
|---|---|---|---|
| Pseudomonas (rhizosphere isolate) — ontology label: Pseudomonas | NCBITaxon:286 · TaxonMech · TraitMech |
PRIMARY_PRODUCER
|
N/A |
|
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| Rahnella (rhizosphere isolate) — ontology label: Rahnella | NCBITaxon:34037 · TaxonMech · TraitMech |
PRIMARY_PRODUCER
|
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.
Cadmium tolerance of the Pseudomonas-Rahnella pair
The selected Pseudomonas-Rahnella pair was reported to tolerate approximately 2 mM cadmium. This is a trait of the tested pair, not a causal co-selection step or evidence that the partners occupy distinct niches. The reviewed abstract does not resolve the assay setting or each member's quantitative contribution.
Participating Taxa: Pseudomonas (rhizosphere isolate), Rahnella (rhizosphere isolate)
Metabolites: cadmium(2+) (CHEBI:48775 · MediaIngredientMech · CMMMech)
Biological Processes:
- response to metal ion (GO:0010038 · PathwayMech)
Evidence
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doi:10.1016/j.indcrop.2025.122518 - SUPPORT (OTHER)"The selected Pseudomonas-Rahnella pair exhibited strong Cd tolerance (~ 2 mM), Plant growth promotion (PGP) traits, and carbon fixation capacity."
Functionally complementary Pseudomonas-Rahnella pairing with minimal antagonism
The source describes top-down assembly of a functionally complementary Pseudomonas-Rahnella SynCom with minimal antagonism. This supports the reported compatibility/design rationale, not demonstrated spatial or temporal niche separation, reduced resource competition, or stable reciprocal fitness benefits. No causal direction between the two members is resolved.
Source Taxon: Pseudomonas (rhizosphere isolate)
Target Taxon: Rahnella (rhizosphere isolate)
Biological Processes:
- biological process involved in interspecies interaction between organisms (GO:0044419 · PathwayMech)
Evidence
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doi:10.1016/j.indcrop.2025.122518 - PARTIAL (OTHER)"A top-down design strategy guided the assembly of a simplified, yet functionally complementary SynCom with minimal antagonism."
Joint PGP and carbon-fixation capacity
The selected pair was reported to possess plant-growth-promoting traits and carbon-fixation capacity. These positive traits do not establish mutualism between the bacteria or quantify their contribution to plant benefit and persistent soil-carbon storage. The capacity claim is retained without turning it into a measured sequestration flux.
Participating Taxa: Pseudomonas (rhizosphere isolate), Rahnella (rhizosphere isolate)
Biological Processes:
- carbon fixation (GO:0015977 · PathwayMech)
Evidence
-
doi:10.1016/j.indcrop.2025.122518 - SUPPORT (OTHER)"The selected Pseudomonas-Rahnella pair exhibited strong Cd tolerance (~ 2 mM), Plant growth promotion (PGP) traits, and carbon fixation capacity."
Knowledge gaps & discussions (1)
KNOWLEDGE_GAP OPEN How do the reported pair-level traits contribute to the observed plant and soil outcomes?
The whole indexed publisher abstract reports positive plant and soil outcomes, but the committed cache contains only the two trait/design sentences used here. Preserve these supported traits and the prior removal of screening-order arrows. Low antagonism does not establish niche partitioning, and carbon-fixation capacity does not isolate a durable soil-carbon contribution. No new causal topology or unsupported assay provenance is introduced.
Attaches to: ecological_interactions#Cadmium tolerance of the Pseudomonas-Rahnella pair, ecological_interactions#Functionally complementary Pseudomonas-Rahnella pairing with minimal antagonism, ecological_interactions#Joint PGP and carbon-fixation capacity
2 evidence item(s)
A top-down design strategy guided the assembly of a simplified, yet functionally complementary SynCom with minimal antagonism.
Supports the reported design rationale and minimal antagonism, not proof of the ecological mechanism or its assay setting.
The selected Pseudomonas-Rahnella pair exhibited strong Cd tolerance (~ 2 mM), Plant growth promotion (PGP) traits, and carbon fixation capacity.
Supports the reported pair-level traits and capacity; the abstract does not specify the assay setting or quantify persistent carbon storage from bacterial fixation.
Cross-Mech Suite Links
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