title: Nitrogen deprivation strongly affects photosystem II but not phycoerythrin level in the divinyl-chlorophyll b-containing cyanobacterium Prochlorococcus marinus.
abstract: Effects of nitrogen limitation on Photosystem II (PSII) activities and on phycoerythrin were studied in batch cultures of the marine oxyphotobacterium Prochlorococcus marinus. Dramatic decreases in photochemical quantum yields (F(V)/F(M)), the amplitude of thermoluminescence (TL) B-band, and the rate of Q(A) reoxidation were observed within 12 h of growth in nitrogen-limited conditions. The decline in F(V)/F(M) paralleled changes in the TL B-band amplitude, indicative of losses in PSII activities and formation of non-functional PSII centers. These changes were accompanied by a continuous reduction in D1 protein content. In contrast, nitrogen deprivation did not cause any significant reduction in phycoerythrin content. Our results refute phycoerythrin as a nitrogen storage complex in Prochlorococcus. Regulation of phycoerythrin gene expression in Prochlorococcus is different from that in typical phycobilisome-containing cyanobacteria and eukaryotic algae investigated so far.
authors: Humboldt University, Departmen of Biology, Berlin, Germany.
authors: C
authors: C
authors: Steglich
authors: M
authors: M
authors: Behrenfeld
authors: M
authors: M
authors: Koblizek
authors: H
authors: H
authors: Claustre
authors: S
authors: S
authors: Penno
authors: O
authors: O
authors: Prasil
authors: F
authors: F
authors: Partensky
authors: W R
authors: WR
authors: Hess
mesh_terms: D002734:Chlorophyll / Q000378:metabolism; D000458:Cyanobacteria / Q000378:metabolism*; D045342:Light-Harvesting Protein Complexes; D009584:Nitrogen / Q000172:deficiency*; D010788:Photosynthesis; D045322:Photosynthetic Reaction Center Complex Proteins / Q000378:metabolism*; D045332:Photosystem II Protein Complex; D045524:Phycobilisomes; D010799:Phycoerythrin / Q000032:analysis / Q000378:metabolism*
chemical_list: D045342:Light-Harvesting Protein Complexes; D045322:Photosynthetic Reaction Center Complex Proteins; D045332:Photosystem II Protein Complex; D045524:Phycobilisomes; D010799:Phycoerythrin; D002734:Chlorophyll; C037184:chlorophyll b; D009584:Nitrogen