Abstract
Attack of plants by necrotizing pathogens leads to acquired resistance to the same or other pathogens in tissues adjacent to or remotely located from the site of initial attack. We have used Arabidopsis thaliana inoculated with the incompatible pathogen Pseudomonas syringae pv syringae on the lower leaves to test the induction of systemic reactions. When plants were challenged with Pseudomonas syringae pv syringae in the upper leaves, bacterial titers remained stable in those preinfected on the lower leaves. However, there was a distinct decrease in symptoms that correlated with a local and systemic increase in salicylic acid (SA) and in chitinase activity. Peroxidase activity only increased at the site of infection. No changes in catalase activity were observed, either at the local or at the systemic level. No inhibition of catalase could be detected in tissue in which the endogenous levels of SA were elevated either naturally (after infection) or artificially (after feeding SA to the roots). The activity of catalase in homogenates of A. thaliana leaves could not be inhibited in vitro by SA. SA accumulation was induced by H2O2 in leaves, suggesting a link between H2O2 from the oxidative burst commonly observed during the hypersensitive reaction and the induction of a putative signaling molecule leading to system acquired resistance.
Abstract from the paper’s OpenAlex record, shown for indexing and research. Copyright remains with the authors or the publisher. Read at the source ↗
The text the model read, with the source record’s inline markup (italics, sub- and superscripts) rendered and its character entities decoded; quote offsets refer to the raw text.
Claims 10
Claim · model-written summary
After lower leaf preinfection, upper leaf challenge left bacterial titers stable.
- Taxon
- Arabidopsis thaliana
Arabidopsis thalianat0 - Treatment
- preinfected on the lower leavese0
- Interactor
- Pseudomonas syringae pv syringae
Pseudomonas syringaee0pathogen - Outcome
- bacterial titerse0
- Direction
- remained stablee0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“When plants were challenged with Pseudomonas syringae pv syringae in the upper leaves, bacterial titers remained stable in those preinfected on the lower leaves.”
t0“Arabidopsis thaliana”
Claim · model-written summary
Preinfected plants showed decreased symptoms after upper leaf challenge.
- Taxon
- Arabidopsis thalianaArabidopsis thalianat0
- Treatment
- preinfected on the lower leavese1
- Outcome
- symptomse0
- Direction
- decreasee0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“there was a distinct decrease in symptoms”
t0“Arabidopsis thaliana”
e1“preinfected on the lower leaves”
Claim · model-written summary
Symptom decrease correlated with local and systemic SA increase.
- Taxon
- Arabidopsis thalianaArabidopsis thalianat0
- Compound
- salicylic acid (SA)e0
- Outcome
- decrease in symptomse0
- Direction
- decreasee0
Not reportedOrgan / stage
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“a distinct decrease in symptoms that correlated with a local and systemic increase in salicylic acid (SA)”
t0“Arabidopsis thaliana”
Claim · model-written summary
Symptom decrease correlated with increased local and systemic chitinase activity.
- Taxon
- Arabidopsis thalianaArabidopsis thalianat0
- Gene
- chitinasee0
- Outcome
- chitinase activitye0
- Direction
- increasee0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“a distinct decrease in symptoms that correlated with a local and systemic increase in salicylic acid (SA) and in chitinase activity.”
t0“Arabidopsis thaliana”
Claim · model-written summary
Peroxidase activity rose only at the infection site.
- Taxon
- Arabidopsis thalianaArabidopsis thalianat0
- Organ / stage
- site of infectione0
- Gene
- Peroxidasee0
- Outcome
- Peroxidase activitye0
- Direction
- increasede0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Peroxidase activity only increased at the site of infection.”
t0“Arabidopsis thaliana”
Claim · model-written summary
Catalase activity showed no local or systemic change.
- Taxon
- Arabidopsis thalianaArabidopsis thalianat0
- Gene
- catalasee0
- Outcome
- catalase activitye0
- Direction
- No changese0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“No changes in catalase activity were observed, either at the local or at the systemic level.”
t0“Arabidopsis thaliana”
Claim · model-written summary
Elevated endogenous SA after infection did not inhibit catalase.
- Taxon
- Arabidopsis thalianaArabidopsis thalianat0
- Gene
- catalasee0
- Compound
- SAe0
- Outcome
- inhibition of catalasee0
- Direction
- No inhibitione0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“No inhibition of catalase could be detected in tissue in which the endogenous levels of SA were elevated either naturally (after infection)”
t0“Arabidopsis thaliana”
Claim · model-written summary
Root-fed SA did not inhibit catalase in tissue.
- Taxon
- Arabidopsis thalianaArabidopsis thalianat0
- Treatment
- feeding SA to the rootse0
- Gene
- catalasee0
- Outcome
- inhibition of catalasee0
- Direction
- No inhibitione0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“No inhibition of catalase could be detected in tissue in which the endogenous levels of SA were elevated either naturally (after infection) or artificially (after feeding SA to the roots).”
t0“Arabidopsis thaliana”
Claim · model-written summary
SA did not inhibit catalase activity in leaf homogenates in vitro.
- Taxon
- A. thalianaArabidopsis thalianae0
- Organ / stage
- leavese0
- Treatment
- SAe0
- Gene
- catalasee0
- Outcome
- activity of catalasee0
- Direction
- could not be inhibitede0
- Setting
- in vitroe0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The activity of catalase in homogenates of A. thaliana leaves could not be inhibited in vitro by SA.”
Claim · model-written summary
H2O2 induced SA accumulation in leaves.
- Taxon
- Arabidopsis thalianaArabidopsis thalianat0
- Organ / stage
- leavese0
- Treatment
- H2O2e0
- Outcome
- SA accumulatione0
- Direction
- inducede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“SA accumulation was induced by H2O2 in leaves”
t0“Arabidopsis thaliana”
The same questions in other papers
salicylic acid · physiology: antioxidant enzymes · Arabidopsis thaliana (thale cress)Positive and negative results
3 in the opposite direction
- positive
- positive
- positive
infection · physiology: antioxidant enzymes · Arabidopsis thaliana (thale cress)Positive and negative results
2 in the opposite direction
- positive
- positive
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.