Abstract
Following the transfer of pea plants grown at low irradiance (60 µmol photons m-2 s-1, 16 h light/8 h dark cycles) to high irradiance (390 µmol photons m-2 s-1), the extents and time courses of the increase in the concentrations of thylakoid membrane components on a chlorophyll basis have been determined. The increase in cytochrome f (~ 70%) and plastoquinone (~ 50%) contents occurred with no noticeable lag phase. The increase in photosystem Il reaction centres (PS II, ~ 35%) and ATP synthetase (~ 90%) occurred possibly with a lag period of 1-2 days. In contrast, there was no significant increase in the concentration of P700 (reaction centre) of PS I complex. The concentration of PS II reaction centres measured by atrazine-binding exceeded that from the O2 yield per single-turnover flash by a factor of 1.17 (compared with the expected value of 1.14); this contrasts with the factor of 1.8 obtained by P. A. Jursinic and R. Dennenberg [Arch. Biochem. Biophys. (1985) 241, 540-9]. It is suggested that both methods are equivalent for the determination of PS II reaction centres in active chloroplasts. The stoichiometry of PS II : cyt f: PS I was highly flexible, and not fixed at 1 : 1 : 1. We obtained the stoichiometries of 1.25 : 0.7 : 1.0 for low-light pea chloroplasts and 1.7 : 1.25 : 1.0 for chloroplasts in pea plants that had been transferred to high light for about 10 days, demonstrating the dynamic nature of thylakoid composition and function. In the first 2 days after transferring low light pea plants to high light, the time course of the increase in CO2- and light-saturated rate of leaf photosynthesis corresponded better with that of cyt f and plastoquinone than that of other chloroplast components examined. This suggests that, during the transition period, the relatively prompt increase of cyt b/f and plastoquinone plays a part in enhancing the CO2- and light-saturated rate of leaf photosynthesis.
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Claims 11
Claim · model-written summary
Cytochrome f increased by about 70% after transfer from low to high irradiance, with no noticeable lag.
- Taxon
- Pisum sativum
Lathyrus oleraceust0 - Treatment
- high irradiancee1
- Outcome
- cytochrome fe2
- Direction
- increasee2
- Value
- ~ 70%e2
- Comparator
- low irradiancee1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Pisum sativum”
e1“Following the transfer of pea plants grown at low irradiance (60 µmol photons m-2 s-1, 16 h light/8 h dark cycles) to high irradiance (390 µmol photons m-2 s-1)”
e2“The increase in cytochrome f (~ 70%) and plastoquinone (~ 50%) contents occurred with no noticeable lag phase”
Claim · model-written summary
Plastoquinone increased by about 50% after transfer from low to high irradiance, with no noticeable lag.
- Taxon
- Pisum sativumLathyrus oleraceust0
- Treatment
- high irradiancee1
- Outcome
- plastoquinonee2
- Direction
- increasee2
- Value
- ~ 50%e2
- Comparator
- low irradiancee1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Pisum sativum”
e1“Following the transfer of pea plants grown at low irradiance (60 µmol photons m-2 s-1, 16 h light/8 h dark cycles) to high irradiance (390 µmol photons m-2 s-1)”
e2“The increase in cytochrome f (~ 70%) and plastoquinone (~ 50%) contents occurred with no noticeable lag phase”
Claim · model-written summary
Photosystem II reaction centres increased by about 35%, possibly with a lag of 1-2 days.
- Taxon
- Pisum sativumLathyrus oleraceust0
- Treatment
- high irradiancee1
- Outcome
- photosystem Il reaction centrese3
- Direction
- increasee3
- Value
- ~ 35%e3
- Qualifier
- possibly with a lag period of 1-2 dayse3
- Comparator
- low irradiancee1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Pisum sativum”
e1“Following the transfer of pea plants grown at low irradiance (60 µmol photons m-2 s-1, 16 h light/8 h dark cycles) to high irradiance (390 µmol photons m-2 s-1)”
e3“The increase in photosystem Il reaction centres (PS II, ~ 35%) and ATP synthetase (~ 90%) occurred possibly with a lag period of 1-2 days”
Claim · model-written summary
ATP synthetase increased by about 90% after transfer from low to high irradiance.
- Taxon
- Pisum sativumLathyrus oleraceust0
- Treatment
- high irradiancee1
- Outcome
- ATP synthetasee3
- Direction
- increasee3
- Value
- ~ 90%e3
- Comparator
- low irradiancee1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Pisum sativum”
e1“Following the transfer of pea plants grown at low irradiance (60 µmol photons m-2 s-1, 16 h light/8 h dark cycles) to high irradiance (390 µmol photons m-2 s-1)”
e3“The increase in photosystem Il reaction centres (PS II, ~ 35%) and ATP synthetase (~ 90%) occurred possibly with a lag period of 1-2 days”
Claim · model-written summary
P700 reaction centre concentration of PS I did not increase significantly after transfer to high irradiance.
- Taxon
- Pisum sativumLathyrus oleraceust0
- Treatment
- high irradiancee1
- Outcome
- concentration of P700 (reaction centre) of PS I complexe4
- Direction
- no significant increasee4
- Comparator
- low irradiancee1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Pisum sativum”
e1“Following the transfer of pea plants grown at low irradiance (60 µmol photons m-2 s-1, 16 h light/8 h dark cycles) to high irradiance (390 µmol photons m-2 s-1)”
e4“In contrast, there was no significant increase in the concentration of P700 (reaction centre) of PS I complex”
Claim · model-written summary
The PS II : cyt f : PS I stoichiometry was highly flexible and not fixed at 1 : 1 : 1.
- Taxon
- Pisum sativumLathyrus oleraceust0
- Outcome
- stoichiometry of PS II : cyt f: PS Ie5
- Qualifier
- highly flexiblee5
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Pisum sativum”
e5“The stoichiometry of PS II : cyt f: PS I was highly flexible, and not fixed at 1 : 1 : 1”
Claim · model-written summary
Low-light pea chloroplasts had a PS II : cyt f : PS I stoichiometry of 1.25 : 0.7 : 1.0.
- Taxon
- Pisum sativumLathyrus oleraceust0
- Organ / stage
- chloroplastse6
- Treatment
- low-lighte6
- Outcome
- stoichiometriese6
- Value
- 1.25 : 0.7 : 1.0e6
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Pisum sativum”
e6“We obtained the stoichiometries of 1.25 : 0.7 : 1.0 for low-light pea chloroplasts and 1.7 : 1.25 : 1.0 for chloroplasts in pea plants that had been transferred to high light for about 10 days”
Claim · model-written summary
Chloroplasts of plants transferred to high light for about 10 days had a stoichiometry of 1.7 : 1.25 : 1.0.
- Taxon
- Pisum sativumLathyrus oleraceust0
- Organ / stage
- chloroplastse6
- Treatment
- transferred to high light for about 10 dayse6
- Outcome
- stoichiometriese6
- Value
- 1.7 : 1.25 : 1.0e6
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Pisum sativum”
e6“We obtained the stoichiometries of 1.25 : 0.7 : 1.0 for low-light pea chloroplasts and 1.7 : 1.25 : 1.0 for chloroplasts in pea plants that had been transferred to high light for about 10 days”
Claim · model-written summary
The atrazine-binding PS II reaction centre concentration exceeded the O2-yield estimate by a factor of 1.17.
Verbatim
e1“The concentration of PS II reaction centres measured by atrazine-binding exceeded that from the O2 yield per single-turnover flash by a factor of 1.17 (compared with the expected value of 1.14)”
Claim · model-written summary
Atrazine-binding and O2-yield methods are suggested to be equivalent for PS II reaction centres in active chloroplasts.
Verbatim
e1“It is suggested that both methods are equivalent for the determination of PS II reaction centres in active chloroplasts”
Claim · model-written summary
Prompt increase of cyt b/f and plastoquinone may help enhance the CO2- and light-saturated rate of leaf photosynthesis.
- Taxon
- Pisum sativumLathyrus oleraceust0
- Outcome
- enhancing the CO2- and light-saturated rate of leaf photosynthesise1
- Qualifier
- the relatively prompt increase of cyt b/f and plastoquinonee1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Pisum sativum”
e1“This suggests that, during the transition period, the relatively prompt increase of cyt b/f and plastoquinone plays a part in enhancing the CO2- and light-saturated rate of leaf photosynthesis”
The same questions in other papers
light · molecular: metabolites · Lathyrus oleraceus (pea)Positive and negative results
25 papers in the same direction as this paper · 20 in the opposite direction · 3 reporting no difference from an alternative
- no effect
- negative
- no effect
45 papers more in this group
See all 49 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.