Abstract
Strong inhibition of uncoupled photosynthetic electron transport by Cu(2+) in isolated spinach chloroplasts was observed by measuring changes in O(2) concentration in the reaction medium. Inhibition was dependent not only on the concentration of the inhibitor, but also on the ratio of chlorophyll to inhibitor. Binding of Cu(2+) to the chloroplast membranes resulted in removal of Cu(2+) from solution. When chloroplasts were exposed to preincubation in light, there was increased inhibition as a result of Cu(2+) binding to inhibitory sites. Preincubation in the dark resulted in Cu(2+) binding to noninhibitory sites and decreased inhibition. The degree of inhibition was lower at low light intensities than at high light intensities.When the photosystems were assayed separately, photosystem I was more resistant to inhibition than photosystem II. The most sensitive site to the inhibitor was the oxidizing side of photosystem II.
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Claims 8
Claim · model-written summary
Cu(2+) strongly inhibited uncoupled photosynthetic electron transport in isolated spinach chloroplasts.
- Taxon
- spinach
Spinacia oleraceae1 - Treatment
- Cu(2+)e1
- Outcome
- uncoupled photosynthetic electron transporte1
- Direction
- inhibitione1
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e1“Strong inhibition of uncoupled photosynthetic electron transport by Cu(2+) in isolated spinach chloroplasts was observed by measuring changes in O(2) concentration in the reaction medium”
Claim · model-written summary
Cu(2+) inhibition depended on the ratio of chlorophyll to inhibitor in isolated spinach chloroplasts.
- Taxon
- spinachSpinacia oleraceae2
- Treatment
- ratio of chlorophyll to inhibitore1
- Outcome
- Inhibitione1
Not reportedDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e1“Inhibition was dependent not only on the concentration of the inhibitor, but also on the ratio of chlorophyll to inhibitor”
e2“in isolated spinach chloroplasts”
Claim · model-written summary
Binding of Cu(2+) to chloroplast membranes removed Cu(2+) from solution in isolated spinach chloroplasts.
- Taxon
- spinachSpinacia oleraceae2
- Compound
- Cu(2+)e1
- Outcome
- removal of Cu(2+) from solutione1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e1“Binding of Cu(2+) to the chloroplast membranes resulted in removal of Cu(2+) from solution”
e2“in isolated spinach chloroplasts”
Claim · model-written summary
Preincubation in light increased Cu(2+) inhibition of spinach chloroplasts.
- Taxon
- spinachSpinacia oleraceae2
- Treatment
- preincubation in lighte1
- Outcome
- inhibitione1
- Direction
- increasede1
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e1“When chloroplasts were exposed to preincubation in light, there was increased inhibition as a result of Cu(2+) binding to inhibitory sites”
e2“in isolated spinach chloroplasts”
Claim · model-written summary
Preincubation in the dark decreased Cu(2+) inhibition of spinach chloroplasts.
- Taxon
- spinachSpinacia oleraceae2
- Treatment
- Preincubation in the darke1
- Outcome
- inhibitione1
- Direction
- decreasede1
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e1“Preincubation in the dark resulted in Cu(2+) binding to noninhibitory sites and decreased inhibition”
e2“in isolated spinach chloroplasts”
Claim · model-written summary
The degree of inhibition was lower at low light intensities than at high light intensities.
- Taxon
- spinachSpinacia oleraceae2
- Treatment
- low light intensitiese1
- Outcome
- degree of inhibitione1
- Direction
- lowere1
- Comparator
- high light intensitiese1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e1“The degree of inhibition was lower at low light intensities than at high light intensities”
e2“in isolated spinach chloroplasts”
Claim · model-written summary
Photosystem I was more resistant to inhibition than photosystem II in spinach chloroplasts.
- Taxon
- spinachSpinacia oleraceae2
- Organ / stage
- photosystem Ie1
- Outcome
- more resistant to inhibitione1
- Direction
- more resistante1
- Comparator
- photosystem IIe1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e1“photosystem I was more resistant to inhibition than photosystem II”
e2“in isolated spinach chloroplasts”
Claim · model-written summary
The most sensitive site to the inhibitor was the oxidizing side of photosystem II.
- Taxon
- spinachSpinacia oleraceae2
- Organ / stage
- oxidizing side of photosystem IIe1
- Outcome
- most sensitive site to the inhibitore1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e1“The most sensitive site to the inhibitor was the oxidizing side of photosystem II”
e2“in isolated spinach chloroplasts”
The same questions in other papers
copper(2+) · physiology: photosynthesis · Spinacia oleracea (spinach)Results agree
1 paper in the same direction as this paper
- negative
light · disease · Spinacia oleracea (spinach)Positive and negative results
3 in the opposite direction
- negative
- negative
- negative
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.