Abstract
BACKGROUND: Systemic Acquired Resistance (SAR) is an induced resistance response to pathogens, characterized by the translocation of a long-distance signal from induced leaves to distant tissues to prime them for increased resistance to future infection. DEFECTIVE in INDUCED RESISTANCE 1 (DIR1) has been hypothesized to chaperone a small signaling molecule to distant tissues during SAR in Arabidopsis. RESULTS: DIR1 promoter:DIR1-GUS/dir1-1 lines were constructed to examine DIR1 expression. DIR1 is expressed in seedlings, flowers and ubiquitously in untreated or mock-inoculated mature leaf cells, including phloem sieve elements and companion cells. Inoculation of leaves with SAR-inducing avirulent or virulent Pseudomonas syringae pv tomato (Pst) resulted in Type III Secretion System-dependent suppression of DIR1 expression in leaf cells. Transient expression of fluorescent fusion proteins in tobacco and intercellular washing fluid experiments indicated that DIR1's ER signal sequence targets it for secretion to the cell wall. However, DIR1 expressed without a signal sequence rescued the dir1-1 SAR defect, suggesting that a cytosolic pool of DIR1 is important for the SAR response. CONCLUSIONS: Although expression of DIR1 decreases during SAR induction, the protein localizes to all living cell types of the vasculature, including companion cells and sieve elements, and therefore DIR1 is well situated to participate in long-distance signaling during SAR.
Abstract from the paper’s OpenAlex record; open copy licensed cc-by. 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 8
Claim · model-written summary
DIR1 is expressed in seedlings, flowers and mature leaf cells of untreated or mock-inoculated plants.
- Taxon
- Arabidopsis
Arabidopsise0 - Organ / stage
- mature leaf cellse1
- Treatment
- untreated or mock-inoculatede1
- Gene
- DIR1e1
- Outcome
- expressede1
- Qualifier
- including phloem sieve elements and companion cellse1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“DEFECTIVE in INDUCED RESISTANCE 1 (DIR1) has been hypothesized to chaperone a small signaling molecule to distant tissues during SAR in Arabidopsis”
e1“DIR1 is expressed in seedlings, flowers and ubiquitously in untreated or mock-inoculated mature leaf cells, including phloem sieve elements and companion cells”
Claim · model-written summary
Inoculation of leaves with avirulent or virulent Pseudomonas syringae pv tomato suppressed DIR1 expression in leaf cells in a Type III Secretion System-dependent manner.
- Taxon
- ArabidopsisArabidopsise0
- Organ / stage
- leaf cellse2
- Treatment
- Inoculation of leaves with SAR-inducing avirulent or virulente2
- Interactor
- Pseudomonas syringae pv tomato
Pseudomonas syringaee2pathogen - Gene
- DIR1e2
- Outcome
- DIR1 expressione2
- Direction
- suppressione2
- Qualifier
- Type III Secretion System-dependente2
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“DEFECTIVE in INDUCED RESISTANCE 1 (DIR1) has been hypothesized to chaperone a small signaling molecule to distant tissues during SAR in Arabidopsis”
e2“Inoculation of leaves with SAR-inducing avirulent or virulent Pseudomonas syringae pv tomato (Pst) resulted in Type III Secretion System-dependent suppression of DIR1 expression in leaf cells”
Claim · model-written summary
DIR1 is secreted to the cell wall because its ER signal sequence targets it there.
- Taxon
- ArabidopsisArabidopsise0
- Gene
- DIR1e3
- Outcome
- secretion to the cell walle3
- Qualifier
- ER signal sequencee3
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“DEFECTIVE in INDUCED RESISTANCE 1 (DIR1) has been hypothesized to chaperone a small signaling molecule to distant tissues during SAR in Arabidopsis”
e3“Transient expression of fluorescent fusion proteins in tobacco and intercellular washing fluid experiments indicated that DIR1's ER signal sequence targets it for secretion to the cell wall”
Claim · model-written summary
DIR1 expressed without a signal sequence rescued the SAR defect of dir1-1 plants.
- Taxon
- ArabidopsisArabidopsise0
- Material
- dir1-1e4
- Treatment
- DIR1 expressed without a signal sequencee4
- Gene
- DIR1e4
- Outcome
- SAR defecte4
- Direction
- rescuede4
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“DEFECTIVE in INDUCED RESISTANCE 1 (DIR1) has been hypothesized to chaperone a small signaling molecule to distant tissues during SAR in Arabidopsis”
e4“However, DIR1 expressed without a signal sequence rescued the dir1-1 SAR defect, suggesting that a cytosolic pool of DIR1 is important for the SAR response”
Claim · model-written summary
A cytosolic pool of DIR1 may be important for the SAR response.
- Taxon
- ArabidopsisArabidopsise0
- Gene
- DIR1e4
- Outcome
- SAR responsee4
- Qualifier
- a cytosolic pool of DIR1 is importante4
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“DEFECTIVE in INDUCED RESISTANCE 1 (DIR1) has been hypothesized to chaperone a small signaling molecule to distant tissues during SAR in Arabidopsis”
e4“However, DIR1 expressed without a signal sequence rescued the dir1-1 SAR defect, suggesting that a cytosolic pool of DIR1 is important for the SAR response”
Claim · model-written summary
Expression of DIR1 decreases during SAR induction.
- Taxon
- ArabidopsisArabidopsise0
- Treatment
- SAR inductione5
- Gene
- DIR1e5
- Outcome
- expression of DIR1e5
- Direction
- decreasese5
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“DEFECTIVE in INDUCED RESISTANCE 1 (DIR1) has been hypothesized to chaperone a small signaling molecule to distant tissues during SAR in Arabidopsis”
e5“Although expression of DIR1 decreases during SAR induction, the protein localizes to all living cell types of the vasculature, including companion cells and sieve elements”
Claim · model-written summary
The DIR1 protein localizes to all living cell types of the vasculature, including companion cells and sieve elements.
- Taxon
- ArabidopsisArabidopsise0
- Organ / stage
- all living cell types of the vasculaturee5
- Gene
- DIR1e5
- Outcome
- localizese5
- Qualifier
- including companion cells and sieve elementse5
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“DEFECTIVE in INDUCED RESISTANCE 1 (DIR1) has been hypothesized to chaperone a small signaling molecule to distant tissues during SAR in Arabidopsis”
e5“Although expression of DIR1 decreases during SAR induction, the protein localizes to all living cell types of the vasculature, including companion cells and sieve elements”
Claim · model-written summary
DIR1 is well situated to participate in long-distance signalling during SAR.
- Taxon
- ArabidopsisArabidopsise0
- Gene
- DIR1e6
- Outcome
- long-distance signaling during SARe6
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“DEFECTIVE in INDUCED RESISTANCE 1 (DIR1) has been hypothesized to chaperone a small signaling molecule to distant tissues during SAR in Arabidopsis”
e6“DIR1 is well situated to participate in long-distance signaling during SAR”
The same questions in other papers
inoculation · Pseudomonas syringae · ArabidopsisPositive and negative results
1 paper in the same direction as this paper · 2 in the opposite direction
- positive
- positive
- no effect
resistance inducer · disease · ArabidopsisPositive and negative results
5 papers in the same direction as this paper · 2 in the opposite direction
- negative
- negative
- positive
4 papers more in this group
See all 8 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.