ISSN:
1573-5079
Keywords:
Cyanobacteria (Synechococcus 6301)
;
excitation energy distribution
;
light harvesting
;
photosynthesis
;
state transition
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
Notes:
Abstract The mechanism by which state 1-state 2 transitions in the cyanobacterium Synechococcus 6301 are controlled was investigated by examining the effects of a variety of chemical and illumination treatments which modify the redox state of the plastoquinone pool. The extent to which these treatments modify excitation energy distribution was determined by 77K fluorescence emission spectroscopy. It was found that treatment which lead to the oxidation of the plastoquinone pool induce a shift towards state 1 whereas treatments which lead to the reduction of the plastoquinone pool induce a shift towards state 2. We therefore propose that state transitions in cyanobacteria are triggered by changes in the redox state of plastoquinone or a closely associated electron carrier. Alternative proposals have included control by the extent of cyclic electron transport around PS I and control by localised electrochemical gradients around PS I and PS II. Neither of these proposals is consistent with the results reported here.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00034860
