Abstract
Systemic induction of pathogenesis-related (PR) proteins in tobacco, which occurs during the hypersensitive response to tobacco mosaic virus (TMV), may be caused by a minimum 10-fold systemic increase in endogenous levels of salicylic acid (SA). This rise in SA parallels PR-1 protein induction and occurs in TMV-resistant Xanthi-nc tobacco carrying the N gene, but not in TMV-susceptible (nn) tobacco. By feeding SA to excised leaves of Xanthi-nc (NN) tobacco, we have shown that the observed increase in endogenous SA levels is sufficient for the systemic induction of PR-1 proteins. TMV infection became systemic and Xanthi-nc plants failed to accumulate PR-1 proteins at 32 degrees C. This loss of hypersensitive response at high temperature was associated with an inability to accumulate SA. However, spraying leaves with SA induced PR-1 proteins at both 24 and 32 degrees C. SA is most likely exported from the primary site of infection to the uninfected tissues. A computer model predicts that SA should move rapidly in phloem. When leaves of Xanthi-nc tobacco were excised 24 hr after TMV inoculation and exudates from the cut petioles were collected, the increase in endogenous SA in TMV-inoculated leaves paralleled SA levels in exudates. Exudation and leaf accumulation of SA were proportional to TMV concentration and were higher in light than in darkness. Different components of TMV were compared for their ability to induce SA accumulation and exudation: three different aggregation states of coat protein failed to induce SA, but unencapsidated viral RNA elicited SA accumulation in leaves and phloem. These results further support the hypothesis that SA acts as an endogenous signal that triggers local and systemic induction of PR-1 proteins and, possibly, some components of systemic acquired resistance in NN tobacco.
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 13
Claim · model-written summary
Systemic endogenous salicylic acid increased at least tenfold during the tobacco hypersensitive response to TMV.
- Taxon
- tobacco
Nicotiana tabacume2 - Interactor
- tobacco mosaic virus
Tobacco mosaic viruse1pathogen - Outcome
- endogenous levels of salicylic acide0
- Direction
- increasee0
- Value
- 10-folde0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“a minimum 10-fold systemic increase in endogenous levels of salicylic acid (SA)”
e1“hypersensitive response to tobacco mosaic virus (TMV)”
e2“in tobacco”
Claim · model-written summary
SA rise paralleled PR-1 induction in resistant Xanthi-nc tobacco but was absent in susceptible tobacco.
- Taxon
- tobaccoNicotiana tabacume0
- Material
- Xanthi-nce0
- Interactor
- TMVTobacco mosaic viruse0pathogen
- Gene
- PR-1 proteine0
- Outcome
- rise in SAe0
- Direction
- risee0
- Comparator
- TMV-susceptible (nn) tobaccoe0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“This rise in SA parallels PR-1 protein induction and occurs in TMV-resistant Xanthi-nc tobacco carrying the N gene, but not in TMV-susceptible (nn) tobacco.”
Claim · model-written summary
Feeding SA to excised Xanthi-nc tobacco leaves induced systemic PR-1 proteins.
- Taxon
- tobaccoNicotiana tabacume0
- Material
- Xanthi-nc (NN)e0
- Treatment
- feeding SAe0
- Gene
- PR-1 proteinse0
- Outcome
- systemic induction of PR-1 proteinse0
- Direction
- inductione0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“By feeding SA to excised leaves of Xanthi-nc (NN) tobacco, we have shown that the observed increase in endogenous SA levels is sufficient for the systemic induction of PR-1 proteins.”
Claim · model-written summary
TMV infection became systemic at 32°C.
- Taxon
- tobaccoNicotiana tabacume1
- Material
- Xanthi-nce0
- Interactor
- TMVTobacco mosaic viruse0pathogen
- Outcome
- TMV infection became systemice0
- Qualifier
- 32 degrees Ce0
Not reportedDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“TMV infection became systemic and Xanthi-nc plants failed to accumulate PR-1 proteins at 32 degrees C.”
e1“Xanthi-nc (NN) tobacco”
Claim · model-written summary
Xanthi-nc plants failed to accumulate PR-1 at 32°C.
- Taxon
- tobaccoNicotiana tabacume1
- Material
- Xanthi-nce0
- Gene
- PR-1 proteinse0
- Outcome
- failed to accumulate PR-1 proteinse0
- Qualifier
- 32 degrees Ce0
Not reportedDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Xanthi-nc plants failed to accumulate PR-1 proteins at 32 degrees C.”
e1“Xanthi-nc (NN) tobacco”
Claim · model-written summary
Loss of hypersensitive response at high temperature was associated with failure to accumulate SA.
- Taxon
- tobaccoNicotiana tabacume1
- Compound
- SAe0
- Outcome
- loss of hypersensitive responsee0
- Qualifier
- high temperaturee0
Not reportedDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“This loss of hypersensitive response at high temperature was associated with an inability to accumulate SA.”
e1“in tobacco”
Claim · model-written summary
SA spraying induced PR-1 proteins at both 24 and 32°C.
- Taxon
- tobaccoNicotiana tabacume1
- Treatment
- spraying leaves with SAe0
- Gene
- PR-1 proteinse0
- Outcome
- PR-1 proteinse0
- Direction
- inducede0
- Qualifier
- both 24 and 32 degrees Ce0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“spraying leaves with SA induced PR-1 proteins at both 24 and 32 degrees C.”
e1“in tobacco”
Claim · model-written summary
A computer model predicted rapid SA movement in phloem.
- Taxon
- tobaccoNicotiana tabacume1
- Outcome
- SA should move rapidly in phloeme0
Not reportedComparatorValue
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“A computer model predicts that SA should move rapidly in phloem.”
e1“in tobacco”
Claim · model-written summary
SA accumulation in TMV-inoculated leaves paralleled SA levels in petiole exudates.
- Taxon
- tobaccoNicotiana tabacume1
- Organ / stage
- leavese0
- Interactor
- TMVTobacco mosaic viruse0pathogen
- Outcome
- increase in endogenous SAe0
- Direction
- increasee0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“the increase in endogenous SA in TMV-inoculated leaves paralleled SA levels in exudates.”
e1“leaves of Xanthi-nc tobacco were excised”
Claim · model-written summary
SA exudation and leaf accumulation were proportional to TMV concentration.
- Taxon
- tobaccoNicotiana tabacume1
- Interactor
- TMVTobacco mosaic viruse0pathogen
- Outcome
- Exudation and leaf accumulation of SAe0
Not reportedDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Exudation and leaf accumulation of SA were proportional to TMV concentration”
e1“leaves of Xanthi-nc tobacco were excised”
Claim · model-written summary
SA exudation and leaf accumulation were higher in light than darkness.
- Taxon
- tobaccoNicotiana tabacume1
- Outcome
- Exudation and leaf accumulation of SAe0
- Direction
- highere0
- Qualifier
- lighte0
- Comparator
- darknesse0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Exudation and leaf accumulation of SA were proportional to TMV concentration and were higher in light than in darkness.”
e1“leaves of Xanthi-nc tobacco were excised”
Claim · model-written summary
Three aggregation states of TMV coat protein failed to induce SA.
- Taxon
- tobaccoNicotiana tabacume1
- Treatment
- three different aggregation states of coat proteine0
- Interactor
- TMVTobacco mosaic viruse2pathogen
- Outcome
- failed to induce SAe0
- Direction
- failed to inducee0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“three different aggregation states of coat protein failed to induce SA”
e1“leaves of Xanthi-nc tobacco were excised”
e2“components of TMV”
Claim · model-written summary
Unencapsidated viral RNA elicited SA accumulation in leaves and phloem.
- Taxon
- tobaccoNicotiana tabacume1
- Organ / stage
- leaves and phloeme0
- Treatment
- unencapsidated viral RNAe0
- Interactor
- TMVTobacco mosaic viruse2pathogen
- Outcome
- SA accumulatione0
- Direction
- elicitede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“unencapsidated viral RNA elicited SA accumulation in leaves and phloem”
e1“leaves of Xanthi-nc tobacco were excised”
e2“components of TMV”
The same questions in other papers
salicylic acid · molecular: expression · Nicotiana tabacum (tobacco)Positive and negative results
24 papers in the same direction as this paper · 11 in the opposite direction
- no effect
- positive
- negative
32 papers more in this group
See all 36 papers →infection · molecular: expression · Nicotiana tabacum (tobacco)Positive and negative results
16 papers in the same direction as this paper · 3 in the opposite direction
- negative
- negative
- negative
16 papers more in this group
See all 20 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.