Abstract
Members of the MILDEW RESISTANCE LOCUS O (MLO) gene family confer susceptibility to powdery mildews in different plant species, and their existence therefore seems to be disadvantageous for the plant. We recognized that expression of the Arabidopsis MLO2 gene is induced after inoculation with the bacterial pathogen Pseudomonas syringae, promoted by salicylic acid (SA) signaling, and systemically enhanced in the foliage of plants exhibiting systemic acquired resistance (SAR). Importantly, distinct mlo2 mutant lines were unable to systemically increase resistance to bacterial infection after inoculation with P. syringae, indicating that the function of MLO2 is necessary for biologically induced SAR in Arabidopsis. Our data also suggest that the close homolog MLO6 has a supportive but less critical role in SAR. In contrast to SAR, basal resistance to bacterial infection was not affected in mlo2. Remarkably, SAR-defective mlo2 mutants were still competent in systemically increasing the levels of the SAR-activating metabolites pipecolic acid (Pip) and SA after inoculation, and to enhance SAR-related gene expression in distal plant parts. Furthermore, although MLO2 was not required for SA- or Pip-inducible defense gene expression, it was essential for the proper induction of disease resistance by both SAR signals. We conclude that MLO2 acts as a critical downstream component in the execution of SAR to bacterial infection, being required for the translation of elevated defense responses into disease resistance. Moreover, our data suggest a function for MLO2 in the activation of plant defense priming during challenge by P. syringae.
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Claims 13
Claim · model-written summary
Pseudomonas syringae inoculation induced Arabidopsis MLO2 expression.
- Taxon
- Arabidopsis
Arabidopsise0 - Treatment
- inoculation with the bacterial pathogen Pseudomonas syringaee0
- Interactor
- Pseudomonas syringae
Pseudomonas syringaee0pathogen - Gene
- Arabidopsis MLO2e0
- Outcome
- expression of the Arabidopsis MLO2 genee0
- Direction
- inducede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“expression of the Arabidopsis MLO2 gene is induced after inoculation with the bacterial pathogen Pseudomonas syringae”
Claim · model-written summary
Salicylic acid signaling promoted MLO2 induction.
- Taxon
- ArabidopsisArabidopsise0
- Gene
- Arabidopsis MLO2e0
- Compound
- salicylic acid (SA)e0
- Outcome
- expression of the Arabidopsis MLO2 genee0
- Direction
- promotede0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“expression of the Arabidopsis MLO2 gene is induced after inoculation with the bacterial pathogen Pseudomonas syringae, promoted by salicylic acid (SA) signaling”
Claim · model-written summary
MLO2 expression was systemically enhanced in foliage undergoing systemic acquired resistance.
- Taxon
- ArabidopsisArabidopsise1
- Gene
- Arabidopsis MLO2e1
- Outcome
- foliagee0
- Direction
- enhancede0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“systemically enhanced in the foliage of plants exhibiting systemic acquired resistance (SAR)”
e1“Arabidopsis MLO2 gene”
Claim · model-written summary
Distinct mlo2 mutants failed to increase systemic resistance after bacterial inoculation.
- Taxon
- ArabidopsisArabidopsise1
- Material
- mlo2 mutant linese0
- Treatment
- inoculation with P. syringaee0
- Interactor
- P. syringaePseudomonas syringaee0pathogen
- Outcome
- resistance to bacterial infectione0
- Direction
- unable to systemically increasee0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“distinct mlo2 mutant lines were unable to systemically increase resistance to bacterial infection after inoculation with P. syringae”
e1“in Arabidopsis”
Claim · model-written summary
MLO6 has a supportive but less critical role in systemic acquired resistance.
- Taxon
- ArabidopsisArabidopsise1
- Gene
- MLO6e0
- Outcome
- SARe0
- Qualifier
- supportive but less critical rolee0
Not reportedDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“the close homolog MLO6 has a supportive but less critical role in SAR”
e1“in Arabidopsis”
Claim · model-written summary
Basal resistance to bacterial infection was unaffected in mlo2 mutants.
- Taxon
- ArabidopsisArabidopsise1
- Material
- mlo2e0
- Outcome
- basal resistance to bacterial infectione0
- Direction
- not affectede0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“basal resistance to bacterial infection was not affected in mlo2”
e1“in Arabidopsis”
Claim · model-written summary
mlo2 mutants still systemically increased pipecolic acid after inoculation.
- Taxon
- ArabidopsisArabidopsise1
- Material
- mlo2 mutantse0
- Treatment
- inoculatione0
- Outcome
- levels of the SAR-activating metabolites pipecolic acid (Pip)e0
- Direction
- increasinge0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“SAR-defective mlo2 mutants were still competent in systemically increasing the levels of the SAR-activating metabolites pipecolic acid (Pip) and SA after inoculation”
e1“in Arabidopsis”
Claim · model-written summary
mlo2 mutants still systemically increased salicylic acid after inoculation.
- Taxon
- ArabidopsisArabidopsise1
- Material
- mlo2 mutantse0
- Treatment
- inoculatione0
- Outcome
- SAe0
- Direction
- increasinge0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“SAR-defective mlo2 mutants were still competent in systemically increasing the levels of the SAR-activating metabolites pipecolic acid (Pip) and SA after inoculation”
e1“in Arabidopsis”
Claim · model-written summary
mlo2 mutants enhanced systemic acquired resistance related gene expression in distal tissues.
- Taxon
- ArabidopsisArabidopsise2
- Material
- mlo2 mutantse1
- Organ / stage
- distal plant partse0
- Outcome
- SAR-related gene expressione0
- Direction
- enhancee0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“to enhance SAR-related gene expression in distal plant parts”
e1“SAR-defective mlo2 mutants”
e2“in Arabidopsis”
Claim · model-written summary
MLO2 was unnecessary for salicylic-acid-inducible defense gene expression.
- Taxon
- ArabidopsisArabidopsise1
- Gene
- MLO2e0
- Outcome
- SA- or Pip-inducible defense gene expressione0
- Direction
- not requirede0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“MLO2 was not required for SA- or Pip-inducible defense gene expression”
e1“in Arabidopsis”
Claim · model-written summary
MLO2 was necessary for proper disease resistance induction by both systemic acquired resistance signals.
- Taxon
- ArabidopsisArabidopsise2
- Gene
- MLO2e1
- Outcome
- proper induction of disease resistancee0
- Qualifier
- both SAR signalse0
Not reportedDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“it was essential for the proper induction of disease resistance by both SAR signals”
e1“MLO2 was not required”
e2“in Arabidopsis”
Claim · model-written summary
MLO2 acts downstream in systemic acquired resistance, translating defense responses into bacterial resistance.
- Taxon
- ArabidopsisArabidopsise1
- Gene
- MLO2e0
- Outcome
- disease resistancee0
- Qualifier
- translation of elevated defense responsese0
Not reportedDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“MLO2 acts as a critical downstream component in the execution of SAR to bacterial infection, being required for the translation of elevated defense responses into disease resistance”
e1“in Arabidopsis”
Claim · model-written summary
MLO2 may contribute to defense priming during P. syringae challenge.
- Taxon
- ArabidopsisArabidopsise1
- Interactor
- P. syringaePseudomonas syringaee0pathogen
- Gene
- MLO2e0
- Outcome
- plant defense priminge0
Not reportedDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“a function for MLO2 in the activation of plant defense priming during challenge by P. syringae”
e1“in Arabidopsis”
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See all 25 papers →Claims are grouped by organism, treatment and what was measured or targeted. A paper counts as positive when any of its claims in the group is positive.