Abstract
The rhizosphere microbiome plays an important role in carbon- and nitrogen-cycling in soil and in the stress response of plants. It also affects the function of the ammonium transporter (AmtB) that senses nitrogen levels inside and outside the cells of the associative nitrogen-fixing bacterium GXGL-4A. However, the potential mechanism of the interaction between the AmtB deletion mutant of GXGL-4A (∆amtB) and microorganisms in the rhizosphere of plants under low-nitrogen stress is still unclear. As revealed by transcriptome analyses, mutation of the amtB gene in GXGL-4A resulted in a significant up-regulation of many functional genes associated with nitrogen fixation and transportation at transcription level. The application of ∆amtB changed the nitrogen level in the rhizosphere of cucumber seedlings and reshaped the microbial community structure in the rhizosphere, enriching the relative abundance of Actinobacteriota and Gemmatimonadota. Based on bacterial functional prediction analyses, the metabolic capacities of rhizobacteria were improved after inoculation of cucumber seedlings with the original strain GXGL-4A or the ∆amtB mutant, resulting in the enhancement of amino acids, lipids, and carbohydrates in the cucumber rhizosphere, which promoted the growth of cucumber plants under a low-nitrogen stress condition. The results contribute to understanding the biological function of gene amtB, revealing the regulatory role of the strain GXGL-4A on cucumber rhizosphere nitrogen metabolism and laying a theoretical foundation for the development of efficient nitrogen-fixing bacterial agents for sustainable agricultural production.
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Claims 12
Claim · model-written summary
Deleting amtB in GXGL-4A upregulated genes for nitrogen fixation and transport.
- Taxon
- Cucumber
Cucumis sativust0 - Interactor
- GXGL-4Ae0symbiont
- Gene
- amtB genee0
- Outcome
- functional genes associated with nitrogen fixation and transportatione0
- Direction
- up-regulatione0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“mutation of the amtB gene in GXGL-4A resulted in a significant up-regulation of many functional genes associated with nitrogen fixation and transportation at transcription level”
t0“Cucumber Plant”
Claim · model-written summary
Applying the GXGL-4A amtB mutant changed nitrogen levels in cucumber seedling rhizospheres.
- Taxon
- cucumberCucumis sativuse0
- Organ / stage
- seedlingse0
- Treatment
- application of ∆amtBe0
- Interactor
- GXGL-4At0symbiont
- Outcome
- nitrogen level in the rhizospheree0
Not reportedComparatorDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The application of ∆amtB changed the nitrogen level in the rhizosphere of cucumber seedlings”
t0“Bacterium GXGL-4A”
Claim · model-written summary
Applying the GXGL-4A amtB mutant reshaped cucumber rhizosphere microbial structure.
- Taxon
- cucumberCucumis sativuse0
- Treatment
- application of ∆amtBe0
- Interactor
- GXGL-4At0symbiont
- Outcome
- microbial community structure in the rhizospheree0
Not reportedComparatorDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The application of ∆amtB changed the nitrogen level in the rhizosphere of cucumber seedlings and reshaped the microbial community structure in the rhizosphere”
t0“Bacterium GXGL-4A”
Claim · model-written summary
Applying the amtB mutant enriched Actinobacteriota in cucumber rhizospheres.
- Taxon
- cucumberCucumis sativuse1
- Treatment
- application of ∆amtBe1
- Interactor
- ActinobacteriotaActinomycetotae0symbiont
- Second interactor
- GXGL-4At0symbiont
- Outcome
- relative abundance of Actinobacteriotae0
- Direction
- enrichinge0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“enriching the relative abundance of Actinobacteriota and Gemmatimonadota”
e1“The application of ∆amtB changed the nitrogen level in the rhizosphere of cucumber seedlings”
t0“Bacterium GXGL-4A”
Claim · model-written summary
Applying the amtB mutant enriched Gemmatimonadota in cucumber rhizospheres.
- Taxon
- cucumberCucumis sativuse1
- Treatment
- application of ∆amtBe1
- Interactor
- GemmatimonadotaGemmatimonadotae0symbiont
- Second interactor
- GXGL-4At0symbiont
- Outcome
- relative abundance of Actinobacteriota and Gemmatimonadotae0
- Direction
- enrichinge0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“enriching the relative abundance of Actinobacteriota and Gemmatimonadota”
e1“The application of ∆amtB changed the nitrogen level in the rhizosphere of cucumber seedlings”
t0“Bacterium GXGL-4A”
Claim · model-written summary
Inoculation with original GXGL-4A improved predicted metabolic capacities of cucumber rhizobacteria.
- Taxon
- cucumberCucumis sativuse0
- Treatment
- inoculation of cucumber seedlings with the original strain GXGL-4Ae0
- Interactor
- GXGL-4Ae0symbiont
- Outcome
- metabolic capacities of rhizobacteriae0
- Direction
- improvede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“the metabolic capacities of rhizobacteria were improved after inoculation of cucumber seedlings with the original strain GXGL-4A or the ∆amtB mutant”
Claim · model-written summary
Inoculation with the GXGL-4A amtB mutant improved predicted metabolic capacities of cucumber rhizobacteria.
- Taxon
- cucumberCucumis sativuse0
- Treatment
- inoculation of cucumber seedlings with the original strain GXGL-4A or the ∆amtB mutante0
- Interactor
- GXGL-4At0symbiont
- Outcome
- metabolic capacities of rhizobacteriae0
- Direction
- improvede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“the metabolic capacities of rhizobacteria were improved after inoculation of cucumber seedlings with the original strain GXGL-4A or the ∆amtB mutant”
t0“Bacterium GXGL-4A”
Claim · model-written summary
Inoculation increased amino acids in the cucumber rhizosphere.
- Taxon
- cucumberCucumis sativuse0
- Treatment
- inoculation of cucumber seedlings with the original strain GXGL-4A or the ∆amtB mutante1
- Interactor
- GXGL-4Ae1symbiont
- Outcome
- amino acidse0
- Direction
- enhancemente0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“resulting in the enhancement of amino acids, lipids, and carbohydrates in the cucumber rhizosphere”
e1“inoculation of cucumber seedlings with the original strain GXGL-4A or the ∆amtB mutant”
Claim · model-written summary
Inoculation increased lipids in the cucumber rhizosphere.
- Taxon
- cucumberCucumis sativuse0
- Treatment
- inoculation of cucumber seedlings with the original strain GXGL-4A or the ∆amtB mutante1
- Interactor
- GXGL-4Ae1symbiont
- Outcome
- lipidse0
- Direction
- enhancemente0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“resulting in the enhancement of amino acids, lipids, and carbohydrates in the cucumber rhizosphere”
e1“inoculation of cucumber seedlings with the original strain GXGL-4A or the ∆amtB mutant”
Claim · model-written summary
Inoculation increased carbohydrates in the cucumber rhizosphere.
- Taxon
- cucumberCucumis sativuse0
- Treatment
- inoculation of cucumber seedlings with the original strain GXGL-4A or the ∆amtB mutante1
- Interactor
- GXGL-4Ae1symbiont
- Outcome
- carbohydratese0
- Direction
- enhancemente0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“resulting in the enhancement of amino acids, lipids, and carbohydrates in the cucumber rhizosphere”
e1“inoculation of cucumber seedlings with the original strain GXGL-4A or the ∆amtB mutant”
Claim · model-written summary
Inoculation with GXGL-4A promoted cucumber growth under low nitrogen.
- Taxon
- cucumberCucumis sativuse0
- Treatment
- inoculation of cucumber seedlings with the original strain GXGL-4Ae1
- Interactor
- GXGL-4Ae1symbiont
- Outcome
- growth of cucumber plantse0
- Direction
- promotede0
- Qualifier
- low-nitrogen stress conditione0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“promoted the growth of cucumber plants under a low-nitrogen stress condition”
e1“inoculation of cucumber seedlings with the original strain GXGL-4A or the ∆amtB mutant”
Claim · model-written summary
Inoculation with the GXGL-4A amtB mutant promoted cucumber growth under low nitrogen.
- Taxon
- cucumberCucumis sativuse0
- Treatment
- inoculation of cucumber seedlings with the original strain GXGL-4A or the ∆amtB mutante1
- Interactor
- GXGL-4At0symbiont
- Outcome
- growth of cucumber plantse0
- Direction
- promotede0
- Qualifier
- low-nitrogen stress conditione0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“promoted the growth of cucumber plants under a low-nitrogen stress condition”
e1“inoculation of cucumber seedlings with the original strain GXGL-4A or the ∆amtB mutant”
t0“Bacterium GXGL-4A”
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