title: Effects of Inorganic Carbon Limitation on the Metabolome of the Synechocystis sp. PCC 6803 Mutant Defective in glnB Encoding the Central Regulator PII of Cyanobacterial C/N Acclimation.
abstract: Cyanobacteria are the only prokaryotes performing oxygenic photosynthesis. Non-diazotrophic strains such as the model Synechocystis sp. PCC 6803 depend on a balanced uptake and assimilation of inorganic carbon and nitrogen sources. The internal C/N ratio is sensed via the PII protein (GlnB). We analyzed metabolic changes of the DglnB mutant of Synechocystis sp. PCC 6803 under different CO2 availability. The identified metabolites provided a snapshot of the central C/N metabolism. Cells of the DglnB mutant shifted to carbon-limiting conditions, i.e. a decreased C/N ratio, showed changes in intermediates of the sugar storage and particularly of the tricarboxylic acid cycle, arginine, and glutamate metabolism. The changes of the metabolome support the notion that the PII protein is primarily regulating the N-metabolism whereas the changes in C-metabolism are probably secondary effects of the PII deletion.
authors: Universität Rostock, Institut Biowissenschaften, Pflanzenphysiologie, Albert-Einstein-Str. 3, D-18059 Rostock, Germany. doreen.schwarz2@uni-rostock.de.
authors: Doreen
authors: D
authors: Schwarz
authors: Max-Planck-Institut für Molekulare Pflanzenphysiologie, Am Mühlenberg 1, 14476 Golm, Germany. orf@mpimp-golm.mpg.de.
authors: Isabel
authors: I
authors: Orf
authors: Max-Planck-Institut für Molekulare Pflanzenphysiologie, Am Mühlenberg 1, 14476 Golm, Germany. kopka@mpimp-golm.mpg.de.
authors: Joachim
authors: J
authors: Kopka
authors: Universität Rostock, Institut Biowissenschaften, Pflanzenphysiologie, Albert-Einstein-Str. 3, D-18059 Rostock, Germany. martin.hagemann@uni-rostock.de.
authors: Martin
authors: M
authors: Hagemann