Abstract
Remodeling of photosynthetic machinery induced by growing spinach plants under low light intensities reveals an up-regulation of light-harvesting complexes and down-regulation of photosystem II and cytochrome b6f complexes in intact thylakoids and isolated grana membranes. The antenna size of PSII increased by 40-60% as estimated by fluorescence induction and LHCII/PSII stoichiometry. These low-light-induced changes in the protein composition were accompanied by the formation of ordered particle arrays in the exoplasmic fracture face in grana thylakoids detected by freeze-fracture electron microscopy. Most likely these highly ordered arrays consist of PSII complexes. A statistical analysis of the particles in these structures shows that the distance of neighboring complexes in the same row is 18.0 nm, the separation between two rows is 23.7 nm, and the angle between the particle axis and the row is 26 degrees . On the basis of structural information on the photosystem II supercomplex, a model on the supramolecular arrangement was generated predicting that two neighboring complexes share a trimeric light-harvesting complex. It was suggested that the supramolecular reorganization in ordered arrays in low-light grana thylakoids is a strategy to overcome potential diffusion problems in this crowded membrane. Furthermore, the occurrence of a hexagonal phase of the lipid monogalactosyldiacylglycerol in grana membranes of low-light-adapted plants could trigger the rearrangement by changing the lateral membrane pressure.
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Claims 11
Claim · model-written summary
Growing spinach plants under low light intensities up-regulated light-harvesting complexes.
- Taxon
- spinach
Spinacia oleraceae0 - Treatment
- low light intensitiese0
- Outcome
- light-harvesting complexese0
- Direction
- up-regulatione0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“growing spinach plants under low light intensities reveals an up-regulation of light-harvesting complexes”
Claim · model-written summary
Growing spinach plants under low light intensities down-regulated photosystem II and cytochrome b6f complexes.
- Taxon
- spinachSpinacia oleraceae0
- Treatment
- low light intensitiese0
- Outcome
- photosystem II and cytochrome b6f complexese0
- Direction
- down-regulatione0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“growing spinach plants under low light intensities reveals an up-regulation of light-harvesting complexes and down-regulation of photosystem II and cytochrome b6f complexes”
Claim · model-written summary
Low-light growth increased the antenna size of PSII in spinach by 40-60%, estimated by fluorescence induction and LHCII/PSII stoichiometry.
- Taxon
- spinachSpinacia oleraceae0
- Treatment
- low light intensitiese0
- Outcome
- antenna size of PSIIe1
- Direction
- increasede1
- Value
- 40-60%e1
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“growing spinach plants under low light intensities”
e1“The antenna size of PSII increased by 40-60% as estimated by fluorescence induction and LHCII/PSII stoichiometry”
Claim · model-written summary
Low-light-induced changes in protein composition were accompanied by formation of ordered particle arrays in the exoplasmic fracture face of grana thylakoids, detected by freeze-fracture electron microscopy.
- Taxon
- spinachSpinacia oleraceae0
- Organ / stage
- grana thylakoidse1
- Outcome
- formation of ordered particle arrayse1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“growing spinach plants”
e1“the formation of ordered particle arrays in the exoplasmic fracture face in grana thylakoids detected by freeze-fracture electron microscopy”
Claim · model-written summary
Most likely the highly ordered arrays in spinach grana thylakoids consist of PSII complexes.
- Taxon
- spinachSpinacia oleraceae0
- Outcome
- highly ordered arrays consist of PSII complexese1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“growing spinach plants”
e1“Most likely these highly ordered arrays consist of PSII complexes”
Claim · model-written summary
In the ordered arrays, the distance between neighboring complexes in the same row was 18.0 nm.
- Taxon
- spinachSpinacia oleraceae0
- Outcome
- distance of neighboring complexes in the same rowe1
- Value
- 18.0 nme1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“growing spinach plants”
e1“the distance of neighboring complexes in the same row is 18.0 nm”
Claim · model-written summary
In the ordered arrays, the separation between two rows was 23.7 nm.
- Taxon
- spinachSpinacia oleraceae0
- Outcome
- separation between two rowse1
- Value
- 23.7 nme1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“growing spinach plants”
e1“the separation between two rows is 23.7 nm”
Claim · model-written summary
In the ordered arrays, the angle between the particle axis and the row was 26 degrees.
- Taxon
- spinachSpinacia oleraceae0
- Outcome
- angle between the particle axis and the rowe1
- Value
- 26 degreese1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“growing spinach plants”
e1“the angle between the particle axis and the row is 26 degrees”
Claim · model-written summary
A model built from the PSII supercomplex structure predicted that two neighboring complexes share a trimeric light-harvesting complex.
- Taxon
- spinachSpinacia oleraceae0
- Outcome
- two neighboring complexes share a trimeric light-harvesting complexe1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“growing spinach plants”
e1“a model on the supramolecular arrangement was generated predicting that two neighboring complexes share a trimeric light-harvesting complex”
Claim · model-written summary
The authors suggest that supramolecular reorganization into ordered arrays in low-light grana thylakoids is a strategy to overcome potential diffusion problems in the crowded membrane.
- Taxon
- spinachSpinacia oleraceae0
- Outcome
- supramolecular reorganization in ordered arrayse1
- Qualifier
- overcome potential diffusion problems in this crowded membranee1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“growing spinach plants”
e1“It was suggested that the supramolecular reorganization in ordered arrays in low-light grana thylakoids is a strategy to overcome potential diffusion problems in this crowded membrane”
Claim · model-written summary
A hexagonal phase of the lipid monogalactosyldiacylglycerol in grana membranes of low-light-adapted plants could trigger the rearrangement by changing lateral membrane pressure.
- Taxon
- spinachSpinacia oleraceae0
- Compound
- monogalactosyldiacylglycerole1
- Outcome
- rearrangemente1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“growing spinach plants”
e1“the occurrence of a hexagonal phase of the lipid monogalactosyldiacylglycerol in grana membranes of low-light-adapted plants could trigger the rearrangement by changing the lateral membrane pressure”