Abstract
The role of the redox-active tripeptide glutathione in plant defence against pathogens has been studied extensively; however, the impact of changes in cellular glutathione redox potential on signalling processes during defence reactions has remained elusive. This study explored the impact of elevated glutathione content on the cytosolic redox potential and on early defence signalling at the level of mitogen-activated protein kinases (MAPKs), as well as on subsequent defence reactions, including changes in salicylic acid (SA) content, pathogenesis-related gene expression, callose depositions, and the hypersensitive response. Wild-type (WT) Nicotiana tabacum L. and transgenic high-glutathione lines (HGL) were transformed with the cytosol-targeted sensor GRX1-roGFP2 to monitor the cytosolic redox state. Surprisingly, HGLs displayed an oxidative shift in their cytosolic redox potential and an activation of the tobacco MAPKs wound-induced protein kinase (WIPK) and SA-induced protein kinase (SIPK). This activation occurred in the absence of any change in free SA content, but was accompanied by constitutively increased expression of several defence genes. Similarly, rapid activation of MAPKs could be induced in WT tobacco by exposure to either reduced or oxidized glutathione. When HGL plants were challenged with adapted or non-adapted Pseudomonas syringae pathovars, the cytosolic redox shift was further amplified and the defence response was markedly increased, showing a priming effect for SA and callose; however, the initial and transient hyperactivation of MAPK signalling was attenuated in HGLs. The results suggest that, in tobacco, MAPK and SA signalling may operate independently, both possibly being modulated by the glutathione redox potential. Possible mechanisms for redox-mediated MAPK activation are discussed.
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 9
Claim · model-written summary
High glutathione lines showed an oxidative cytosolic redox shift.
- Taxon
- tobacco
Nicotiana tabacumt0 - Material
- HGLse0
- Outcome
- cytosolic redox potentiale0
- Direction
- oxidative shifte0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“HGLs displayed an oxidative shift in their cytosolic redox potential and an activation of the tobacco MAPKs wound-induced protein kinase (WIPK) and SA-induced protein kinase (SIPK).”
t0“tobacco”
Claim · model-written summary
High glutathione lines activated WIPK and SIPK.
- Taxon
- tobaccoNicotiana tabacume0
- Material
- HGLse0
- Gene
- wound-induced protein kinase (WIPK) and SA-induced protein kinase (SIPK)e0
- Outcome
- activatione0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“HGLs displayed an oxidative shift in their cytosolic redox potential and an activation of the tobacco MAPKs wound-induced protein kinase (WIPK) and SA-induced protein kinase (SIPK).”
Claim · model-written summary
The MAPK activation occurred without a change in free SA content.
- Taxon
- tobaccoNicotiana tabacumt0
- Outcome
- free SA contente0
- Direction
- absence of any changee0
Not reportedMaterial
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“This activation occurred in the absence of any change in free SA content, but was accompanied by constitutively increased expression of several defence genes.”
t0“tobacco”
Claim · model-written summary
High glutathione lines had constitutively increased defence gene expression.
- Taxon
- tobaccoNicotiana tabacumt0
- Outcome
- expression of several defence genese0
- Direction
- increasede0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“This activation occurred in the absence of any change in free SA content, but was accompanied by constitutively increased expression of several defence genes.”
t0“tobacco”
Claim · model-written summary
Reduced glutathione induced rapid MAPK activation in wild type tobacco.
- Taxon
- tobaccoNicotiana tabacume0
- Material
- WT tobaccoe0
- Treatment
- reducede0
- Outcome
- activation of MAPKse0
- Direction
- activatione0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“rapid activation of MAPKs could be induced in WT tobacco by exposure to either reduced or oxidized glutathione.”
Claim · model-written summary
Oxidized glutathione induced rapid MAPK activation in wild type tobacco.
- Taxon
- tobaccoNicotiana tabacume0
- Material
- WT tobaccoe0
- Treatment
- oxidized glutathionee0
- Outcome
- activation of MAPKse0
- Direction
- activatione0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“rapid activation of MAPKs could be induced in WT tobacco by exposure to either reduced or oxidized glutathione.”
Claim · model-written summary
Pseudomonas challenge further amplified the cytosolic redox shift in high glutathione lines.
- Taxon
- tobaccoNicotiana tabacumt0
- Treatment
- challenged with adapted or non-adapted Pseudomonas syringae pathovarse0
- Interactor
- Pseudomonas syringae
Pseudomonas syringaee0pathogen - Outcome
- cytosolic redox shifte0
- Direction
- further amplifiede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“When HGL plants were challenged with adapted or non-adapted Pseudomonas syringae pathovars, the cytosolic redox shift was further amplified and the defence response was markedly increased, showing a priming effect for SA and callose; however, the initial and transient hyperactivation of MAPK signalling was attenuated in HGLs.”
t0“tobacco”
Claim · model-written summary
Pseudomonas challenge increased defence response and priming for SA and callose in high glutathione lines.
- Taxon
- tobaccoNicotiana tabacumt0
- Treatment
- challenged with adapted or non-adapted Pseudomonas syringae pathovarse0
- Interactor
- Pseudomonas syringaePseudomonas syringaee0pathogen
- Outcome
- defence responsee0
- Direction
- markedly increasede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“When HGL plants were challenged with adapted or non-adapted Pseudomonas syringae pathovars, the cytosolic redox shift was further amplified and the defence response was markedly increased, showing a priming effect for SA and callose; however, the initial and transient hyperactivation of MAPK signalling was attenuated in HGLs.”
t0“tobacco”
Claim · model-written summary
Initial transient MAPK hyperactivation was attenuated in challenged high glutathione lines.
- Taxon
- tobaccoNicotiana tabacumt0
- Material
- HGLse0
- Outcome
- hyperactivation of MAPK signallinge0
- Direction
- attenuatede0
Not reportedTreatmentComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“the initial and transient hyperactivation of MAPK signalling was attenuated in HGLs.”
t0“tobacco”
The same questions in other papers
Pseudomonas syringae · disease · Nicotiana tabacum (tobacco)Results agree
1 paper in the same direction as this paper
- positive
infection · disease · Nicotiana tabacum (tobacco)Positive and negative results
3 papers in the same direction as this paper · 10 in the opposite direction · 1 reporting no difference from an alternative
- negative
- negative
- negative
11 papers more in this group
See all 15 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.