ISSN:
1432-2048
Keywords:
Cytochrome c-553
;
Photophosphorylation (cyclic)
;
Plastidic cytochrome c-553
;
Plastocyanin induction
;
Scenedesmus
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
Notes:
Abstract Physiological conditions necessary for the formation of plastocyanin and the concurrent cessation of cytochrome c-553 formation were studied in cells of copper-deficient Scenedesmus acutus after the addition of copper. Plastocyanin is formed after a lag-phase, leaving constant the content of plastidic cytochrome c-553. Therefore, the concentration of plastocyanin per cell increases and the concentration of cytochrome c-553 decreases during growth. Formation of plastocyanin during the induction period studied is dependent on light intensity. In the dark, there is a 90% inhibition, whereas under light intensities above 50 Wm-2, a ratio of 1.3 molecules plastocyanin per 1,000 molecules chlorophyll is attained. Plastocyanin formations is inhibited by the uncoupler carbonylcyanide-p-trifluoromethoxy phenylhydrazone (FCCP), but not by moderate concentrations of 3-[3′,4′-dichlorophenyl]-1,1-dimethylurea (DCMU), and by keeping the algae under a nitrogen atmosphere without CO2. Concurrently, the cultures treated with FCCP show a decreased endogenous ATP level. The ATP is necessary for plastocyanin formation.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00379841
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