Abstract
Brassinosteroids (BRs) play a vital role in plant growth, stress tolerance and productivity. Here, the involvement of BRs in the regulation of CO(2) assimilation and cellular redox homeostasis was studied. The effects of BRs on CO(2) assimilation were studied in cucumber (Cucumis sativus) through the analysis of the accumulation of H(2)O(2) and glutathione and photosynthesis-related enzyme activities using histochemical and cytochemical detection or a spectrophotometric assay, and Rubisco activase (RCA) using western blot analysis and immunogold labeling. Exogenous BR increased apoplastic H(2)O(2) accumulation, the ratio of reduced to oxidized glutathione (GSH:GSSG) and CO(2) assimilation, whereas a BR biosynthetic inhibitor had the opposite effects. BR-induced CO(2) assimilation was decreased by a H(2)O(2) scavenger or inhibition of H(2)O(2) generation, GSH biosynthesis and the NADPH-generating pentose phosphate pathway. BR-, H(2)O(2) - or GSH-induced CO(2) assimilation was associated with increased activity of enzymes in the Benson-Calvin cycle. Immunogold labeling and western blotting showed that BR increased the content of RCA and this effect was blocked by inhibitors of redox homeostasis. These results strongly suggest that BR-induced photosynthesis involves an H(2)O(2) -mediated increase in the GSH:GSSG ratio, which may positively regulate the synthesis and activation of redox-sensitive enzymes in carbon fixation.
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Claims 8
Claim · model-written summary
Exogenous brassinosteroid increased apoplastic H2O2, the GSH:GSSG ratio and CO2 assimilation in cucumber.
- Taxon
- Cucumis sativus
Cucumis sativust0 - Treatment
- Exogenous BRe1
- Outcome
- CO(2) assimilatione1
- Direction
- increasede1
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Cucumis sativus”
e1“Exogenous BR increased apoplastic H(2)O(2) accumulation, the ratio of reduced to oxidized glutathione (GSH:GSSG) and CO(2) assimilation”
Claim · model-written summary
A brassinosteroid biosynthetic inhibitor decreased CO2 assimilation in cucumber.
- Taxon
- Cucumis sativusCucumis sativust0
- Treatment
- BR biosynthetic inhibitore2
- Outcome
- CO(2) assimilatione1
- Direction
- decreaseinferrede2
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Cucumis sativus”
e1“Exogenous BR increased apoplastic H(2)O(2) accumulation, the ratio of reduced to oxidized glutathione (GSH:GSSG) and CO(2) assimilation”
e2“whereas a BR biosynthetic inhibitor had the opposite effects”
Claim · model-written summary
H2O2 scavenger decreased BR-induced CO2 assimilation in cucumber.
- Taxon
- Cucumis sativusCucumis sativust0
- Treatment
- H(2)O(2) scavengere3
- Outcome
- CO(2) assimilatione3
- Direction
- decreasede3
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Cucumis sativus”
e3“BR-induced CO(2) assimilation was decreased by a H(2)O(2) scavenger or inhibition of H(2)O(2) generation, GSH biosynthesis and the NADPH-generating pentose phosphate pathway”
Claim · model-written summary
Inhibiting GSH biosynthesis decreased BR-induced CO2 assimilation in cucumber.
- Taxon
- Cucumis sativusCucumis sativust0
- Treatment
- GSH biosynthesise3
- Outcome
- CO(2) assimilatione3
- Direction
- decreasede3
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Cucumis sativus”
e3“BR-induced CO(2) assimilation was decreased by a H(2)O(2) scavenger or inhibition of H(2)O(2) generation, GSH biosynthesis and the NADPH-generating pentose phosphate pathway”
Claim · model-written summary
Inhibiting the NADPH-generating pentose phosphate pathway decreased BR-induced CO2 assimilation in cucumber.
- Taxon
- Cucumis sativusCucumis sativust0
- Treatment
- NADPH-generating pentose phosphate pathwaye3
- Outcome
- CO(2) assimilatione3
- Direction
- decreasede3
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Cucumis sativus”
e3“BR-induced CO(2) assimilation was decreased by a H(2)O(2) scavenger or inhibition of H(2)O(2) generation, GSH biosynthesis and the NADPH-generating pentose phosphate pathway”
Claim · model-written summary
BR-, H2O2- or GSH-induced CO2 assimilation was associated with increased activity of Benson-Calvin cycle enzymes.
- Taxon
- Cucumis sativusCucumis sativust0
- Compound
- GSHe4
- Outcome
- activity of enzymes in the Benson-Calvin cyclee4
- Direction
- increasede4
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Cucumis sativus”
e4“BR-, H(2)O(2) - or GSH-induced CO(2) assimilation was associated with increased activity of enzymes in the Benson-Calvin cycle”
Claim · model-written summary
BR increased Rubisco activase content in cucumber, and this effect was blocked by redox homeostasis inhibitors.
- Taxon
- Cucumis sativusCucumis sativust0
- Treatment
- BRe5
- Gene
- RCAe5
- Outcome
- content of RCAe5
- Direction
- increasede5
- Qualifier
- blocked by inhibitors of redox homeostasise5
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Cucumis sativus”
e5“Immunogold labeling and western blotting showed that BR increased the content of RCA and this effect was blocked by inhibitors of redox homeostasis”
Claim · model-written summary
BR-induced photosynthesis may involve an H2O2-mediated increase in the GSH:GSSG ratio.
- Taxon
- Cucumis sativusCucumis sativust0
- Outcome
- BR-induced photosynthesise6
- Qualifier
- H(2)O(2) -mediated increase in the GSH:GSSG ratioe6
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Cucumis sativus”
e6“These results strongly suggest that BR-induced photosynthesis involves an H(2)O(2) -mediated increase in the GSH:GSSG ratio”
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1 paper more in this group
See all 5 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.