Abstract
Abstract We evaluated the ability of metabolic elicitors extracted from Pseudomonas fluorescens N21.4 to induce systemic resistance (ISR) in Arabidopsis thaliana against the pathogen Pseudomonas syringae DC3000. Metabolic elicitors were obtained from bacteria-free culture medium with n-hexane, ethyl acetate and n-butanol in three consecutive extractions. Each extract showed plant protection activity. The n-hexane fraction was the most effective and was used to study the signal transduction pathways involved by evaluating expression of marker genes of the salicylic acid (SA) signalling pathway (NPR1, PR1, ICS and PR2) and the jasmonic acid/ethylene (JA/ET) signalling pathway (PDF1, MYC2, LOX2 and PR3). In addition, the level of oxidative stress was tested by determining the activity of enzymes related to the ascorbate-glutathione cycle. N-hexane extracts stimulated both pathways based on overexpression of ICS, PR1, PR2, PDF1 and LOX2 genes. In addition, activity of the pathogenesis-related proteins glucanase (PR2) and chitinase (PR3), lipoxygenase and polyphenol oxidase was enhanced together with an increased capacity to remove reactive oxygen species (ROS). This was associated with less oxidative stress as indicated by a decrease in malondialdehyde (MDA), suggesting a causative link between defensive metabolism against P. syringae and ROS scavenging.
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Claims 6
Claim · model-written summary
Each bacterial extract protected Arabidopsis plants.
- Taxon
- Arabidopsis thaliana
Arabidopsis thalianae1 - Treatment
- Each extracte0
- Interactor
- Pseudomonas syringae DC3000Pseudomonas syringae pv. tomato str. DC3000e1pathogen
- Outcome
- plant protection activitye0
- Direction
- protectione0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Each extract showed plant protection activity.”
e1“Arabidopsis thaliana against the pathogen Pseudomonas syringae DC3000”
Claim · model-written summary
The n-hexane fraction provided the strongest protection.
- Taxon
- Arabidopsis thalianaArabidopsis thalianae1
- Treatment
- n-hexane fractione0
- Interactor
- Pseudomonas syringae DC3000Pseudomonas syringae pv. tomato str. DC3000e1pathogen
- Outcome
- most effectivee0
- Direction
- most effectivee0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The n-hexane fraction was the most effective”
e1“Arabidopsis thaliana against the pathogen Pseudomonas syringae DC3000”
Claim · model-written summary
N-hexane extracts increased expression of ICS, PR1, PR2, PDF1 and LOX2.
- Taxon
- Arabidopsis thalianaArabidopsis thalianae1
- Treatment
- N-hexane extractse0
- Gene
- ICS, PR1, PR2, PDF1 and LOX2e0
- Outcome
- overexpression of ICS, PR1, PR2, PDF1 and LOX2 genese0
- Direction
- overexpressione0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“N-hexane extracts stimulated both pathways based on overexpression of ICS, PR1, PR2, PDF1 and LOX2 genes.”
e1“Arabidopsis thaliana”
Claim · model-written summary
N-hexane extracts enhanced activities of four defense enzymes.
- Taxon
- Arabidopsis thalianaArabidopsis thalianae2
- Treatment
- N-hexane extractse1
- Gene
- glucanase (PR2) and chitinase (PR3), lipoxygenase and polyphenol oxidasee0
- Outcome
- activity of the pathogenesis-related proteinse0
- Direction
- enhancede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“activity of the pathogenesis-related proteins glucanase (PR2) and chitinase (PR3), lipoxygenase and polyphenol oxidase was enhanced”
e1“N-hexane extracts stimulated both pathways”
e2“Arabidopsis thaliana”
Claim · model-written summary
N-hexane extracts increased reactive oxygen species removal capacity.
- Taxon
- Arabidopsis thalianaArabidopsis thalianae2
- Treatment
- N-hexane extractse1
- Outcome
- capacity to remove reactive oxygen species (ROS)e0
- Direction
- increasede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“an increased capacity to remove reactive oxygen species (ROS)”
e1“N-hexane extracts stimulated both pathways”
e2“Arabidopsis thaliana”
Claim · model-written summary
Malondialdehyde decreased, indicating less oxidative stress.
- Taxon
- Arabidopsis thalianaArabidopsis thalianae1
- Outcome
- malondialdehyde (MDA)e0
- Direction
- decreasee0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“less oxidative stress as indicated by a decrease in malondialdehyde (MDA)”
e1“Arabidopsis thaliana”
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