Abstract
3-(3',4'-Dichlorophenyl)-1',1'-dimethyl urea (DCMU) induced the photobleaching of chlorophylls and carotenoids in isolated chloroplasts of Hordeum vulgare. In chloroplasts illuminated in both the absence and presence of DCMU (5.0 mmol m−3), the destruction of carotenoid preceded that of the chlorophylls. The rate of photodestruction was accelerated by the presence of DCMU. After only 2 h illumination the rates of loss of β-carotene and of the epoxyxanthophylls, neoxanthin and violaxanthin, were similar (approximately 40–50% loss in the presence of 5–0 mmol m−3 DCMU) but weremuch greater than that of lutein (25% loss). Analysis of the individual pigment-protein complexes, isolated from chloroplasts following such treatment, showed that whilst pigment destruction had occurred in all complexes, the relative content of the LHCP2/CPa complexes (containing the PSII core) had fallen to the greatest extent. Further illumination of the chloroplasts, for up to 22 h, resulted in far greater bleaching but showed a similar pattern of pigment loss, with DCMU again accelerating the rate at which this loss occurred. β-Carotene-5,6-epoxide was identified as a product of such photo-oxidative conditions.
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Claims 10
Claim · model-written summary
DCMU induced photobleaching of chlorophylls and carotenoids.
- Taxon
- Hordeum vulgare
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Hordeum vulgaree0 - Organ / stage
- isolated chloroplastse0
- Treatment
- 3-(3',4'-Dichlorophenyl)-1',1'-dimethyl urea (DCMU)e0
- Outcome
- photobleaching of chlorophylls and carotenoidse0
- Direction
- inducede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
.jpg?width=500)
Verbatim
e0“3-(3',4'-Dichlorophenyl)-1',1'-dimethyl urea (DCMU) induced the photobleaching of chlorophylls and carotenoids in isolated chloroplasts of Hordeum vulgare”
Claim · model-written summary
Carotenoid destruction preceded chlorophyll destruction with and without DCMU.
Not reportedTaxon
Verbatim
e0“In chloroplasts illuminated in both the absence and presence of DCMU (5.0 mmol m−3), the destruction of carotenoid preceded that of the chlorophylls”
t0“Higher Plants”
Claim · model-written summary
DCMU accelerated the rate of photodestruction.
Not reportedTaxonComparator
Verbatim
e0“The rate of photodestruction was accelerated by the presence of DCMU”
t0“Higher Plants”
Claim · model-written summary
After two hours, beta-carotene loss was about 40–50%.
- Treatment
- DCMUe0
- Outcome
- loss of β-carotenee0
- Direction
- losse0
- Value
- 40–50%e0
- Qualifier
- After only 2 h illuminatione0
Not reportedTaxon
Verbatim
e0“After only 2 h illumination the rates of loss of β-carotene and of the epoxyxanthophylls, neoxanthin and violaxanthin, were similar (approximately 40–50% loss in the presence of 5–0 mmol m−3 DCMU) but weremuch greater than that of lutein (25% loss)”
t0“Higher Plants”
Claim · model-written summary
Neoxanthin and violaxanthin loss was about 40–50% after two hours.
- Treatment
- DCMUe0
- Outcome
- loss of β-carotene and of the epoxyxanthophylls, neoxanthin and violaxanthine0
- Direction
- losse0
- Value
- 40–50%e0
Not reportedTaxon
Verbatim
e0“After only 2 h illumination the rates of loss of β-carotene and of the epoxyxanthophylls, neoxanthin and violaxanthin, were similar (approximately 40–50% loss in the presence of 5–0 mmol m−3 DCMU) but weremuch greater than that of lutein (25% loss)”
t0“Higher Plants”
Claim · model-written summary
Lutein loss was 25%, lower than the other pigments.
Not reportedTaxon
Verbatim
e0“but weremuch greater than that of lutein (25% loss)”
t0“Higher Plants”
Claim · model-written summary
Pigment destruction occurred in all complexes.
- Outcome
- pigment destructione0
Not reportedTaxon
Verbatim
e0“pigment destruction had occurred in all complexes”
t0“Higher Plants”
Claim · model-written summary
LHCP2/CPa complexes fell to the greatest extent.
Not reportedTaxon
Verbatim
e0“the relative content of the LHCP2/CPa complexes (containing the PSII core) had fallen to the greatest extent”
t0“Higher Plants”
Claim · model-written summary
Further illumination up to 22 hours caused greater bleaching with a similar pattern.
Not reportedTaxonComparator
Verbatim
e0“Further illumination of the chloroplasts, for up to 22 h, resulted in far greater bleaching but showed a similar pattern of pigment loss”
t0“Higher Plants”
Claim · model-written summary
Beta-carotene-5,6-epoxide was identified as a photo-oxidative product.
- Outcome
- β-Carotene-5,6-epoxide was identifiede0
Not reportedTaxon
Verbatim
e0“β-Carotene-5,6-epoxide was identified as a product of such photo-oxidative conditions”
t0“Higher Plants”
The same questions in other papers
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See all 18 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.