scholarly journals Contrasting Behavior of Higher Plant Photosystem I and II Antenna Systems during Acclimation

2007 ◽  
Vol 282 (12) ◽  
pp. 8947-8958 ◽  
Author(s):  
Matteo Ballottari ◽  
Luca Dall'Osto ◽  
Tomas Morosinotto ◽  
Roberto Bassi
Keyword(s):  
Photosystem I ◽  
Higher Plant ◽  
Photosystem I And Ii ◽  
Antenna Systems

scholarly journals The light-harvesting complexes of higher-plant Photosystem I: Lhca1/4 and Lhca2/3 form two red-emitting heterodimers

2011 ◽  
Vol 433 (3) ◽  
pp. 477-485 ◽  
Author(s):  
Emilie Wientjes ◽  
Roberta Croce
Keyword(s):  
Photosystem I ◽  
Light Harvesting ◽  
Fluorescence Emission ◽  
Light Response ◽  
Native State ◽  
Higher Plant ◽  
Light Harvesting Complexes ◽  
Light Harvesting Complex ◽  
Wavelength Emission

The outer antenna of higher-plant PSI (Photosystem I) is composed of four complexes [Lhc (light-harvesting complex) a1–Lhca4] belonging to the light-harvesting protein family. Difficulties in their purification have so far prevented the determination of their properties and most of the knowledge about Lhcas has been obtained from the study of the in vitro reconstituted antennas. In the present study we were able to purify the native complexes, showing that Lhca2/3 and Lhca1/4 form two functional heterodimers. Both dimers show red-fluorescence emission with maxima around 730 nm, as in the intact PSI complex. This indicates that the dimers are in their native state and that LHCI-680, which was previously assumed to be part of the PSI antenna, does not represent the native state of the system. The data show that the light-harvesting properties of the two dimers are functionally identical, concerning absorption, long-wavelength emission and fluorescence quantum yield, whereas they differ in their high-light response. Implications of the present study for the understanding of the energy transfer process in PSI are discussed. Finally, the comparison of the properties of the native dimers with those of the reconstituted complexes demonstrates that all of the major properties of the Lhcas are reproduced in the in vitro systems.

scholarly journals Origin of the 701-nm Fluorescence Emission of the Lhca2 Subunit of Higher Plant Photosystem I

2004 ◽  
Vol 279 (47) ◽  
pp. 48543-48549 ◽  
Author(s):  
Roberta Croce ◽  
Tomas Morosinotto ◽  
Janne A. Ihalainen ◽  
Agnieszka Chojnicka ◽  
Jacques Breton ◽  
...  
Keyword(s):  
Photosystem I ◽  
Fluorescence Emission ◽  
Higher Plant

Lipid Composition of Photosystem I and II in the Tobacco Mutant Nicotiana tabacum NC 95

1988 ◽  
Vol 43 (5-6) ◽  
pp. 423-430 ◽  
Author(s):  
J. Bednarz ◽  
A. Radunz ◽  
G. H. Schmid
Keyword(s):  
Photosystem Ii ◽  
Photosystem I ◽  
Lipid Composition ◽  
Green Leaf ◽  
Phospholipid Content ◽  
Lamellar System ◽  
Lipid Mixture ◽  
Intact Chloroplasts ◽  
Photosystem I And Ii ◽  
Photosystem Ii Particles

The lipids of photosystem II particles, of chloroplasts and leaves are compared in the variegated tobacco mutant NC 95. The mutant differs from other N. tabacum mutants by the phenomenon that it has variegated leaves with green and with yellow-green leaf patches. Chloroplasts from the green leaf areas exhibit photosystem II and photosystem I reactions and have a normal lamellar system with grana and intergrana regions. Chloroplasts from the yellow-green leaf areas, however, yield only photosystem I reactions and have only single stranded isolated thylakoids. Hence, this mutant offers the unique possibility to compare without the use of detergents within the same plant the lipid composition of photosystem II particles with that in intact chloroplasts, exhibiting either photosystem II and I reactions or those exhibiting exclusively photosystem I reactions. The lipids of photosystem II particles are composed of 37 % glycolipids, 4 % phospholipids, 5 % carotenoids and 54 % chlorophyll. Lipids of chloroplasts with grana stacking are composed of 75% glycolipids, 7 % phospholipids, 2 % carotenoids and 16% chlorophyll. Chloroplasts with single isolated thylakoids have a lipid composition consisting of 8 3 % glycolipids, 14% phospholipids and only 0.5% carotenoids and 2 % chlorophyll. The chloroplast lipid mixture is characterized in comparison to the respective leaf lipid mixture by a 16-17% higher glycolipid portion and by a 13-70% lower phospholipid content. The main difference in the lipid composition of photosystem I and II consists in the observation that chloroplasts active in only photosystem I contain more than double the amount of glycolipids and the 4-fold amount of phospholipids in comparison to photosystem II active preparations. The amount of monogalactolipid is even 3 times higher in chloroplasts active only in photosystem I when compared to those in photosystem II particles. In photosystem II particles phosphatidylethanolamine is completely lacking and phosphatidylglycerol and phosphatidylinositol occur only in traces. The fatty acids of the sulfolipid are by 45 % more saturated in the photosystem II particles and the digalactolipids of the photosystem II particles are by 28 % more saturated than in chloroplasts exhibiting photosystem I and II activity.

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