Photosensitization of triplet carotenoid in photosynthetic light-harvesting complex of photosystem II

1988 ◽  
Vol 92 (5) ◽  
pp. 1165-1168 ◽  
Author(s):  
R. Nechushtai ◽  
J. P. Thornber ◽  
L. K. Patterson ◽  
R. W. Fessenden ◽  
H. Levanon
Keyword(s):  
Photosystem Ii ◽  
Light Harvesting ◽  
Light Harvesting Complex

scholarly journals Spatial relationship of photosystem I, photosystem II, and the light-harvesting complex in chloroplast membranes.

1977 ◽  
Vol 73 (2) ◽  
pp. 400-418 ◽  
Author(s):  
P A Armond ◽  
L A Staehelin ◽  
C J Arntzen
Keyword(s):  
Particle Size ◽  
Photosystem Ii ◽  
Photosystem I ◽  
Light Harvesting ◽  
Particle Density ◽  
Unit Size ◽  
Fracture Face ◽  
Photosynthetic Unit ◽  
Light Harvesting Complex ◽  
Chloroplast Membrane

We have previously demonstrated (Armond, P. A., C. J. Arntzen, J.-M. Briantais, and C. Vernotte. 1976. Arch. Biochem. Biophys. 175:54-63; and Davis, D. J., P. A. Armond, E. L. Gross, and C. J. Arntzen. 1976. Arch. Biochem. Biophys. 175:64-70) that pea seedlings which were exposed to intermittent illumination contained incompletely developed chloroplasts. These plastids were photosynthetically competent, but did not contain grana. We now demonstrate that the incompletely developed plastids have a smaller photosynthetic unit size; this is primarily due to the absence of a major light-harvesting pigment-protein complex which is present in the mature membranes. Upon exposure of intermittent-light seedlings to continuous white light for periods up to 48 h, a ligh-harvesting chlorophyll-protein complex was inserted into the chloroplast membrane with a concomitant appearance of grana stacks and an increase in photosynthetic unit size. Plastid membranes from plants grown under intermediate light were examined by freeze-fracture electron microscopy. The membrane particles on both the outer (PF) and inner (EF) leaflets of the thylakoid membrane were found to be randomly distributed. The particle density of the PF fracture face was approx. four times that of the EF fracture face. While only small changes in particle density were observed during the greening process under continuous light, major changes in particle size were noted, particularly in the EF particles of stacked regions (EFs) of the chloroplast membrane. Both the changes in particle size and an observed aggregation of the EF particles into the newly stacked regions of the membrane were correlated with the insertion of light-harvesting pigment-protein into the membrane. Evidence is presented for identification of the EF particles as the morphological equivalent of a "complete" photosystem II complex, consisting of a phosochemically active "core" complex surrounded by discrete aggregates of the light-harvesting pigment protein. A model demonstrating the spatial relationships of photosystem I, photosystem II, and the light-harvesting complex in the chloroplast membrane is presented.

Spectral and functional studies on siphonaxanthin-type light-harvesting complex of photosystem II from Bryopsis corticulans

2013 ◽  
Vol 117 (1-3) ◽  
pp. 267-279 ◽  
Author(s):  
Wenda Wang ◽  
Xiaochun Qin ◽  
Min Sang ◽  
Dongqin Chen ◽  
Kebin Wang ◽  
...  
Keyword(s):  
Photosystem Ii ◽  
Light Harvesting ◽  
Light Harvesting Complex ◽  
Functional Studies ◽  
Bryopsis Corticulans
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