Abstract
Previous studies have shown that cytokinins and auxins can induce the opening of stomata. However, the mechanism of stomatal opening caused by cytokinins and auxins remains unclear. The purpose of this paper is to investigate the relationship between hydrogen peroxide (H2O2) levels in guard cells and stomatal opening induced by cytokinins and auxins in Vicia faba. By means of stomatal bioassay and laser-scanning confocal microscopy, we provide evidence that cytokinins and auxins reduced the levels of H2O2 in guard cells and induced stomatal opening in darkness. Additionally, cytokinins not only reduced exogenous H2O2 levels in guard cells caused by exposure to light, but also abolished H2O2 that had been generated during a dark period, and promoted stomatal opening, as did ascorbic acid (ASA, an important reducing substrate for H2O2 removal). However, unlike cytokinins, auxins did not reduce exogenous H2O2, did not abolish H2O2 that had been generated in the dark, and therefore did not promote reopening of stoma induced to close in the dark. The above-mentioned effects of auxins were similar to that of diphenylene iodonium (DPI, an inhibitor of the H2O2-generating enzyme NADPH oxidase). Taken together our results indicate that cytokinins probably reduce the levels of H2O2 in guard cells by scavenging, whereas auxins limit H2O2 levels through restraining H2O2 generation, inducing stomatal opening in darkness.
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Claims 13
Claim · model-written summary
Cytokinins reduced guard cell H2O2 in darkness.
- Taxon
- Vicia faba
Vicia fabat0 - Treatment
- cytokininse0
- Outcome
- levels of H2O2 in guard cellse0
- Direction
- reducede0
- Setting
- darknesse0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“cytokinins and auxins reduced the levels of H2O2 in guard cells and induced stomatal opening in darkness.”
t0“Vicia faba”
Claim · model-written summary
Auxins reduced guard cell H2O2 in darkness.
- Taxon
- Vicia fabaVicia fabat0
- Treatment
- auxinse0
- Outcome
- levels of H2O2 in guard cellse0
- Direction
- reducede0
- Setting
- darknesse0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“cytokinins and auxins reduced the levels of H2O2 in guard cells and induced stomatal opening in darkness.”
t0“Vicia faba”
Claim · model-written summary
Cytokinins induced stomatal opening in darkness.
- Taxon
- Vicia fabaVicia fabat0
- Treatment
- cytokininse0
- Outcome
- stomatal openinge0
- Direction
- inducede0
- Setting
- darknesse0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“cytokinins and auxins reduced the levels of H2O2 in guard cells and induced stomatal opening in darkness.”
t0“Vicia faba”
Claim · model-written summary
Auxins induced stomatal opening in darkness.
- Taxon
- Vicia fabaVicia fabat0
- Treatment
- auxinse0
- Outcome
- stomatal openinge0
- Direction
- inducede0
- Setting
- darknesse0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“cytokinins and auxins reduced the levels of H2O2 in guard cells and induced stomatal opening in darkness.”
t0“Vicia faba”
Claim · model-written summary
Cytokinins reduced light-associated exogenous H2O2 in guard cells.
- Taxon
- Vicia fabaVicia fabat0
- Treatment
- cytokininse0
- Outcome
- exogenous H2O2 levels in guard cellse0
- Direction
- reducede0
- Qualifier
- exposure to lighte0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“cytokinins not only reduced exogenous H2O2 levels in guard cells caused by exposure to light”
t0“Vicia faba”
Claim · model-written summary
Cytokinins abolished H2O2 generated during a dark period.
- Taxon
- Vicia fabaVicia fabat0
- Treatment
- cytokininse1
- Outcome
- H2O2 that had been generated during a dark periode0
- Direction
- abolishede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“abolished H2O2 that had been generated during a dark period”
t0“Vicia faba”
e1“cytokinins and auxins reduced the levels of H2O2 in guard cells and induced stomatal opening in darkness.”
Claim · model-written summary
Cytokinins promoted stomatal opening.
- Taxon
- Vicia fabaVicia fabat0
- Treatment
- cytokininse1
- Outcome
- stomatal openinge0
- Direction
- promotede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“and promoted stomatal opening, as did ascorbic acid (ASA, an important reducing substrate for H2O2 removal).”
t0“Vicia faba”
e1“cytokinins and auxins reduced the levels of H2O2 in guard cells and induced stomatal opening in darkness.”
Claim · model-written summary
Ascorbic acid promoted stomatal opening.
- Taxon
- Vicia fabaVicia fabat0
- Treatment
- ascorbic acide0
- Outcome
- stomatal openinge0
- Direction
- promotede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“and promoted stomatal opening, as did ascorbic acid (ASA, an important reducing substrate for H2O2 removal).”
t0“Vicia faba”
Claim · model-written summary
Auxins did not reduce exogenous H2O2.
- Taxon
- Vicia fabaVicia fabat0
- Treatment
- auxinse0
- Outcome
- exogenous H2O2e0
- Direction
- did not reducee0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“auxins did not reduce exogenous H2O2, did not abolish H2O2 that had been generated in the dark, and therefore did not promote reopening of stoma induced to close in the dark.”
t0“Vicia faba”
Claim · model-written summary
Auxins did not abolish H2O2 generated in darkness.
- Taxon
- Vicia fabaVicia fabat0
- Treatment
- auxinse0
- Outcome
- H2O2 that had been generated in the darke0
- Direction
- did not abolishe0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“auxins did not reduce exogenous H2O2, did not abolish H2O2 that had been generated in the dark, and therefore did not promote reopening of stoma induced to close in the dark.”
t0“Vicia faba”
Claim · model-written summary
Auxins did not promote reopening of dark-closed stomata.
- Taxon
- Vicia fabaVicia fabat0
- Treatment
- auxinse0
- Outcome
- reopening of stoma induced to close in the darke0
- Direction
- did not promotee0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“auxins did not reduce exogenous H2O2, did not abolish H2O2 that had been generated in the dark, and therefore did not promote reopening of stoma induced to close in the dark.”
t0“Vicia faba”
Claim · model-written summary
Cytokinins probably lower guard cell H2O2 by scavenging.
- Taxon
- Vicia fabaVicia fabat0
- Treatment
- cytokininse0
- Outcome
- levels of H2O2 in guard cellse0
- Direction
- reducee0
- Qualifier
- scavenginge0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“cytokinins probably reduce the levels of H2O2 in guard cells by scavenging”
t0“Vicia faba”
Claim · model-written summary
Auxins limit guard cell H2O2 by restraining its generation.
- Taxon
- Vicia fabaVicia fabat0
- Treatment
- auxinse0
- Outcome
- H2O2 levelse0
- Direction
- limite0
- Qualifier
- restraining H2O2 generatione0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“auxins limit H2O2 levels through restraining H2O2 generation”
t0“Vicia faba”
The same questions in other papers
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- positive
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1 paper in the same direction as this paper
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class · physiology: gas exchange · Vicia faba (faba bean)Results agree
1 paper in the same direction as this paper
- positive
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.