Abstract
Abstract Phytoplasmas are phloem‐inhabiting, cell wall‐less bacteria that cause numerous plant diseases worldwide. Plants infected by phytoplasmas often exhibit various symptoms indicative of hormonal imbalance. In this study, we investigated the effects of potato purple top ( PPT ) phytoplasma infection on gibberellin homeostasis in tomato plants. We found that PPT phytoplasma infection caused a significant reduction in endogenous levels of gibberellic acid ( GA 3 ). The decrease in GA 3 content in diseased plants was correlated with down regulation of genes responsible for biosynthesis of bioactive GAs ( GA20ox1 and GA3ox1 ) and genes involved in formation of GA precursors [geranyl diphosphate synthase ( GPS ) and copalyldiphosphate synthase ( CPS )]. Exogenous application of GA 3 at 200 µmol L −1 was able to restore the GA content in infected plants to levels comparable to those in healthy controls, and to attenuate the characteristic ‘big bud’ symptoms induced by the phytoplasma. The interesting observation that PPT phytoplasma‐infected plants had prolonged low expression of key GA biosynthesis genes GA20ox1 and GA3ox1 under GA deficiency conditions led us to hypothesise that there was a diminished sensitivity of the GA metabolism feedback regulation, especially GA biosynthesis negative feedback regulation, in those affected plants, and such diminished sensitization in early stages of infection may represent a central element of the phytoplasma‐induced disruption of GA homeostasis and pathogenesis.
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Claims 6
Claim · model-written summary
PPT infection reduced endogenous GA3 significantly.
- Taxon
- tomato plants
Solanum lycopersicumt0 - Treatment
- PPT phytoplasma infectione0
- Interactor
- PPT phytoplasmae0pathogen
- Outcome
- endogenous levels of gibberellic acid ( GA 3 )e0
- Direction
- reductione0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“PPT phytoplasma infection caused a significant reduction in endogenous levels of gibberellic acid ( GA 3 )”
t0“tomato plants”
Claim · model-written summary
GA3 decrease correlated with downregulation of GA20ox1 and GA3ox1.
- Taxon
- tomato plantsSolanum lycopersicumt0
- Interactor
- PPT phytoplasmae1pathogen
- Gene
- GA20ox1 and GA3ox1e0
- Outcome
- GA 3 contente0
- Direction
- decreasee0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The decrease in GA 3 content in diseased plants was correlated with down regulation of genes responsible for biosynthesis of bioactive GAs ( GA20ox1 and GA3ox1 )”
e1“PPT phytoplasma infection”
t0“tomato plants”
Claim · model-written summary
GA3 decrease correlated with downregulation of GPS and CPS.
- Taxon
- tomato plantsSolanum lycopersicumt0
- Gene
- geranyl diphosphate synthase ( GPS ) and copalyldiphosphate synthase ( CPS )e0
- Outcome
- decrease in GA 3 contente1
- Direction
- decreasee1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“genes involved in formation of GA precursors [geranyl diphosphate synthase ( GPS ) and copalyldiphosphate synthase ( CPS )]”
e1“The decrease in GA 3 content in diseased plants”
t0“tomato plants”
Claim · model-written summary
Exogenous GA3 restored GA content in infected plants.
- Taxon
- tomato plantsSolanum lycopersicumt0
- Treatment
- Exogenous application of GA 3 at 200 µmol L −1e0
- Interactor
- PPT phytoplasmae1pathogen
- Outcome
- GA contente0
- Direction
- restoree0
- Comparator
- healthy controlse0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Exogenous application of GA 3 at 200 µmol L −1 was able to restore the GA content in infected plants to levels comparable to those in healthy controls”
e1“PPT phytoplasma infection”
t0“tomato plants”
Claim · model-written summary
Exogenous GA3 attenuated big bud symptoms.
- Taxon
- tomato plantsSolanum lycopersicumt0
- Treatment
- Exogenous application of GA 3 at 200 µmol L −1e1
- Interactor
- phytoplasma
Candidatus Phytoplasmae0pathogen - Outcome
- ‘big bud’ symptomse0
- Direction
- attenuatee0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“attenuate the characteristic ‘big bud’ symptoms induced by the phytoplasma”
e1“Exogenous application of GA 3 at 200 µmol L −1”
t0“tomato plants”
Claim · model-written summary
The authors hypothesize diminished GA feedback sensitivity in infected plants.
- Taxon
- tomato plantsSolanum lycopersicumt0
- Interactor
- PPT phytoplasmae1pathogen
- Outcome
- diminished sensitivity of the GA metabolism feedback regulatione0
- Qualifier
- GA biosynthesis negative feedback regulatione0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“there was a diminished sensitivity of the GA metabolism feedback regulation, especially GA biosynthesis negative feedback regulation, in those affected plants”
e1“PPT phytoplasma‐infected plants”
t0“tomato plants”
The same questions in other papers
Gibberellic acid · physiology: hormones · Solanum lycopersicum (tomato)Positive and negative results
2 in the opposite direction
- no effect
- negative
Gibberellic acid · Candidatus Phytoplasma · Solanum lycopersicum (tomato)Results agree
1 paper in the same direction as this paper
- positive
infection · physiology: hormones · Solanum lycopersicum (tomato)Positive and negative results
2 papers in the same direction as this paper · 5 in the opposite direction
- positive
- positive
- 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.