Abstract
When leaflets of bean and leaves of other species of C(3) plants are illuminated in the absence of CO(2) and at low O(2) partial pressure, the capacity for CO(2) assimilation at saturating light and its efficiency at low light intensities are inhibited. This photoinhibition is dependent on leaflet age and period of illumination. In young leaflets and following short exposure to these photoinhibitory conditions, some recovery of CO(2) assimilation capacity is observed immediately after treatment. Following substantial (70 to 80%) photoinhibition of CO(2) assimilation, recovery in fully expanded leaflets is observed only after 48 hours in normal air. The photoinhibition is largely prevented by providing CO(2) at partial pressures equivalent to the CO(2) compensation point, or by >210 millibars O(2) which permits internal CO(2) production by photorespiration. If leaflets are illuminated in 60 microbars CO(2) and 210 millibars O(2) (the CO(2) compensation point in air), no photoinhibition is observed. Electron transport processes and fluorescence emission associated with photosystem II are inhibited in chloroplast thylakoids isolated from leaflets after illumination in zero CO(2) and 10 millibars O(2). These studies support the hypothesis that CO(2) recycling through photorespiration is one means of effectively dissipating excess photochemical energy when CO(2) supply to illuminated leaves is limited.
Abstract from the paper’s OpenAlex record, shown for indexing and research. Copyright remains with the authors or the publisher. Read at the source ↗
The text the model read, with the source record’s inline markup (italics, sub- and superscripts) rendered and its character entities decoded; quote offsets refer to the raw text.
Claims 8
Claim · model-written summary
Illumination without CO2 at low O2 inhibits CO2 assimilation capacity and low-light efficiency.
- Taxon
- beane0
- Treatment
- illuminated in the absence of CO(2) and at low O(2) partial pressuree0
- Outcome
- capacity for CO(2) assimilation at saturating light and its efficiency at low light intensitiese0
- Direction
- inhibitede0
Not reportedComparator
Verbatim
e0“When leaflets of bean and leaves of other species of C(3) plants are illuminated in the absence of CO(2) and at low O(2) partial pressure, the capacity for CO(2) assimilation at saturating light and its efficiency at low light intensities are inhibited.”
Claim · model-written summary
Photoinhibition depends on leaflet age and illumination period.
Not reportedDirection
Verbatim
e0“This photoinhibition is dependent on leaflet age and period of illumination.”
e1“When leaflets of bean and leaves of other species of C(3) plants are illuminated in the absence of CO(2) and at low O(2) partial pressure, the capacity for CO(2) assimilation at saturating light and its efficiency at low light intensities are inhibited.”
Claim · model-written summary
Young leaflets partly recover assimilation capacity immediately after brief exposure.
Verbatim
e0“In young leaflets and following short exposure to these photoinhibitory conditions, some recovery of CO(2) assimilation capacity is observed immediately after treatment.”
e1“When leaflets of bean and leaves of other species of C(3) plants are illuminated in the absence of CO(2) and at low O(2) partial pressure, the capacity for CO(2) assimilation at saturating light and its efficiency at low light intensities are inhibited.”
Claim · model-written summary
After 70 to 80% photoinhibition, fully expanded leaflets recover only after 48 hours in normal air.
Verbatim
e0“Following substantial (70 to 80%) photoinhibition of CO(2) assimilation, recovery in fully expanded leaflets is observed only after 48 hours in normal air.”
e1“When leaflets of bean and leaves of other species of C(3) plants are illuminated in the absence of CO(2) and at low O(2) partial pressure, the capacity for CO(2) assimilation at saturating light and its efficiency at low light intensities are inhibited.”
Claim · model-written summary
Providing CO2 at the compensation point largely prevents photoinhibition.
- Taxon
- beane1
- Treatment
- providing CO(2) at partial pressures equivalent to the CO(2) compensation pointe0
- Outcome
- photoinhibitione0
- Direction
- preventede0
Not reportedComparator
Verbatim
e0“The photoinhibition is largely prevented by providing CO(2) at partial pressures equivalent to the CO(2) compensation point, or by >210 millibars O(2) which permits internal CO(2) production by photorespiration.”
e1“When leaflets of bean and leaves of other species of C(3) plants are illuminated in the absence of CO(2) and at low O(2) partial pressure, the capacity for CO(2) assimilation at saturating light and its efficiency at low light intensities are inhibited.”
Claim · model-written summary
Providing more than 210 millibars O2 largely prevents photoinhibition.
Not reportedComparator
Verbatim
e0“The photoinhibition is largely prevented by providing CO(2) at partial pressures equivalent to the CO(2) compensation point, or by >210 millibars O(2) which permits internal CO(2) production by photorespiration.”
e1“When leaflets of bean and leaves of other species of C(3) plants are illuminated in the absence of CO(2) and at low O(2) partial pressure, the capacity for CO(2) assimilation at saturating light and its efficiency at low light intensities are inhibited.”
Claim · model-written summary
Illumination at 60 microbars CO2 and 210 millibars O2 caused no photoinhibition.
- Taxon
- beane1
- Treatment
- illuminated in 60 microbars CO(2) and 210 millibars O(2)e0
- Outcome
- photoinhibitione0
- Direction
- no photoinhibitione0
Not reportedComparator
Verbatim
e0“If leaflets are illuminated in 60 microbars CO(2) and 210 millibars O(2) (the CO(2) compensation point in air), no photoinhibition is observed.”
e1“When leaflets of bean and leaves of other species of C(3) plants are illuminated in the absence of CO(2) and at low O(2) partial pressure, the capacity for CO(2) assimilation at saturating light and its efficiency at low light intensities are inhibited.”
Claim · model-written summary
Illumination at zero CO2 and 10 millibars O2 inhibits thylakoid electron transport and photosystem II fluorescence.
- Taxon
- beane1
- Organ / stage
- leafletse0
- Treatment
- illumination in zero CO(2) and 10 millibars O(2)e0
- Outcome
- Electron transport processes and fluorescence emission associated with photosystem IIe0
- Direction
- inhibitede0
Not reportedComparator
Verbatim
e0“Electron transport processes and fluorescence emission associated with photosystem II are inhibited in chloroplast thylakoids isolated from leaflets after illumination in zero CO(2) and 10 millibars O(2).”
e1“When leaflets of bean and leaves of other species of C(3) plants are illuminated in the absence of CO(2) and at low O(2) partial pressure, the capacity for CO(2) assimilation at saturating light and its efficiency at low light intensities are inhibited.”
The same questions in other papers
light · physiology: photosynthesis · Phaseolus vulgaris (common bean)Positive and negative results
6 papers in the same direction as this paper · 7 in the opposite direction
- positive
- positive
- positive
10 papers more in this group
See all 14 papers →co2 · physiology: photosynthesis · Phaseolus vulgaris (common bean)Positive and negative results
8 papers in the same direction as this paper · 6 in the opposite direction
- no effect
- no effect
- negative
11 papers more in this group
See all 15 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.