Abstract
Reactive oxygen intermediates (ROI) play a critical role in the defense of plants against invading pathogens. Produced during the "oxidative burst," they are thought to activate programmed cell death (PCD) and induce antimicrobial defenses such as pathogenesis-related proteins. It was shown recently that during the interaction of plants with pathogens, the expression of ROI-detoxifying enzymes such as ascorbate peroxidase (APX) and catalase (CAT) is suppressed. It was suggested that this suppression, occurring upon pathogen recognition and coinciding with an enhanced rate of ROI production, plays a key role in elevating cellular ROI levels, thereby potentiating the induction of PCD and other defenses. To examine the relationship between the suppression of antioxidative mechanisms and the induction of PCD and other defenses during pathogen attack, we studied the interaction between transgenic antisense tobacco plants with reduced APX or CAT and a bacterial pathogen that triggers the hypersensitive response. Transgenic plants with reduced capability to detoxify ROI (i.e., antisense APX or CAT) were found to be hyperresponsive to pathogen attack. They activated PCD in response to low amounts of pathogens that did not trigger the activation of PCD in control plants. Our findings support the hypothesis that suppression of ROI-scavenging enzymes during the hypersensitive response plays an important role in enhancing pathogen-induced PCD.
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Claims 3
Claim · model-written summary
Tobacco plants with reduced APX or CAT were hyperresponsive to pathogen attack.
- Taxon
- tobacco
Nicotiana tabacumt0 - Material
- Transgenic plantse0
- Gene
- APX or CATe0
- Outcome
- hyperresponsive to pathogen attacke0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Transgenic plants with reduced capability to detoxify ROI (i.e., antisense APX or CAT) were found to be hyperresponsive to pathogen attack”
t0“tobacco plants”
Claim · model-written summary
Low pathogen doses activated programmed cell death in reduced-antioxidant tobacco but not controls.
- Taxon
- tobaccoNicotiana tabacume1
- Treatment
- low amounts of pathogense0
- Interactor
- a bacterial pathogene1pathogen
- Gene
- APX or CATe1
- Outcome
- PCDe0
- Comparator
- control plantse0
Not reportedDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“They activated PCD in response to low amounts of pathogens that did not trigger the activation of PCD in control plants”
e1“transgenic antisense tobacco plants with reduced APX or CAT and a bacterial pathogen that triggers the hypersensitive response”
Claim · model-written summary
The findings support a role for suppression of ROI-scavenging enzymes in enhanced pathogen-induced cell death.
- Taxon
- tobaccoNicotiana tabacumt0
- Gene
- ROI-scavenging enzymese0
- Outcome
- pathogen-induced PCDe0
- Qualifier
- during the hypersensitive responsee0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“suppression of ROI-scavenging enzymes during the hypersensitive response plays an important role in enhancing pathogen-induced PCD”
t0“tobacco”