Involvement of cyanobacterial phytochromes in growth under different light qualities and quantities.
Inactivation of the genes for the cyanobacterial phytochromes cph1 and cph2 in the unicellular cyanobacterium Synechocystis sp. strain PCC 6803 affected the growth of the cells under certain light conditions. Differences in growth were detected by recording growth curves and in competition experiments. Mutation of cph1 and cph2 resulted in different effects. The cph1-mutant strains exhibited a reduced growth rate under far-red light (FRL), whereas the growth of the cph2-mutant strains was inhibited by red light (RL). The growth rate of a cph1- / cph2- double mutant was reduced under both RL and FRL. Furthermore, cph1-, cph2- as well as double-mutant strains showed impaired growth under high-light (HL) conditions. Acclimation of the photosynthetic apparatus of the mutants to RL, FRL and HL, as determined by pigment analysis, was similar to that of the wild type.
Institut für Biologie, Biochemie der Pflanzen, Humboldt-Universität zu Berlin, Berlin, Germany.
Brita
B
Fiedler
David
D
Broc
Hendrik
H
Schubert
Anne
A
Rediger
Thomas
T
Börner
Annegret
A
Wilde
D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism; D000458:Cyanobacteria / Q000235:genetics / Q000254:growth & development* / Q000378:metabolism / Q000528:radiation effects*; D015964:Gene Expression Regulation, Bacterial / Q000528:radiation effects*; D005798:Genes, Bacterial / Q000235:genetics; D008027:Light; D009154:Mutation / Q000235:genetics; D020283:Photoreceptors, Microbial; D010834:Phytochrome / Q000235:genetics / Q000378:metabolism*; D010860:Pigments, Biological / Q000032:analysis; D011494:Protein Kinases / Q000235:genetics / Q000378:metabolism; D013050:Spectrometry, Fluorescence
D001426:Bacterial Proteins; C413622:Cph2 protein, bacteria; D020283:Photoreceptors, Microbial; D010860:Pigments, Biological; D010834:Phytochrome; D011494:Protein Kinases; C413623:Cph1 phytochrome protein, bacteria