Light-induced changes in the conformation and configuration of the thylakoid membrane of Ulva and Porphyra chloroplasts in vivo
Satoru Murakami,Lester Packer +1 more
TLDR
The ultrastructural basis of light-induced transmission and light scattering changes of thalli of Ulva and Porphyra were investigated and an explanation for the observed conformational and configuration changes was proposed in terms of correlated changes in ionic environment and osmotic properties of chloroplasts in vivo which are initiated by photosynthetic reactions.Abstract:
The ultrastructural basis of light-induced transmission and light scattering changes of thalli of Ulva and Porphyra were investigated by high resolution electron microscopy and microdensitometry. The results show that upon illumination of dark thalli (a) a reduction in thickness of thylakoid membranes (conformational change), (b) a more regular ordering, and (c) flattening of the thylakoids (configurational changes) have occurred. An explanation for the observed conformational and configurational changes was proposed in terms of correlated changes in ionic environment and osmotic properties of chloroplasts in vivo which are initiated by photosynthetic reactions.read more
Citations
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The photoprotective molecular switch in the photosystem II antenna
TL;DR: It is suggested how PsbS and xanthophylls may exert control over qE by controlling the affinity of LHCII complexes for protons with reference to the concepts of hydrophobicity, allostery and hysteresis.
Journal ArticleDOI
Alkalization of the Chloroplast Stroma Caused by Light-Dependent Proton Flux Into the Thylakoid Space
TL;DR: It is discussed that the light-dependent alkalization in the chloroplast stroma may be involved in the regulation of CO2 fixation at the fructose diphosphatase step.
Journal ArticleDOI
Photoprotective Energy Dissipation Involves the Reorganization of Photosystem II Light-Harvesting Complexes in the Grana Membranes of Spinach Chloroplasts
Matthew P. Johnson,Tomasz K. Goral,Christopher D. P. Duffy,Anthony P.R. Brain,Conrad W. Mullineaux,Alexander V. Ruban +5 more
TL;DR: An investigation into the structural basis of light-harvesting regulation in intact spinach chloroplasts using freeze-fracture electron microscopy, combined with laser confocal microscopy employing the fluorescence recovery after photobleaching technique demonstrates that formation of the photoprotective state requires a structural reorganization of the photosynthetic membrane involving dissociation of LHCII from PSII and its aggregation.
Journal ArticleDOI
Chlorophyll a fluorescence in marine centric diatoms: Responses of chloroplasts to light and nutrient stress
TL;DR: An investigation of continuous cultures of Cyclotella nana showed that in vivo chlorophyll a fluoresced more strongly in nitrogen-starved cells than in enriched ones, and photoinhibition of cellular fluorescence also increased with the cell's state of nitrogen deficiency.
References
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Journal ArticleDOI
The nature of the coupling between light energy and active ion transport in nitella translucens.
TL;DR: It is suggested that K + uptake is supported by light energy through the utilization of ATP produced in photophosphorylation, but that the Cl − uptake is directly linked to the light-driven electron-transfer reactions associated with the evolution of O 2 in photosynthesis, and does not depend on photoph phosphorylation.
Journal ArticleDOI
Chloroplast shrinkage and increased photophosphorylation in vitro upon illuminating intact plants of Pisum sativum.
TL;DR: Light-induced chloroplast shrinkage in vivo is discussed in connection with the increased efficiency of photophosphorylation in vitro for chloroplasts isolated from illuminated plants.
Journal ArticleDOI
Phenylmereuric Acetate and Phosphate Control of Light‐Dependent Shrinkage and Reactions in Chloroplasts
TL;DR: It would seem that, in a cyclic electron flow system, in which ATP synthesis is blocked at a late step (e.g. by PMA), shrinkage may be an indirect method for measuring electron flow.
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