PsaE- and NdhF-mediated electron transport affect bicarbonate transport rather than carbon dioxide uptake in the cyanobacterium Synechococcus sp. PCC7002

• Published in: Planta 1997-01, Vol.201 (1), p.36-42
• Main Authors: Sültemeyer, Dieter, Price, G. Dean, Bryant, Donald A., Badger, Murray R.
• Format: Article
• Language: English
• Subjects: Bacteriology; Badgers; Biological and medical sciences; Carbon dioxide; Cell growth; Cyanobacteria; Dehydrogenases; Doubling time; Fundamental and applied biological sciences. Psychology; Metabolism. Enzymes; Microbiology; Oxygen; Photosynthesis; Plants; Thylakoids
• ISSN: 0032-0935; 1432-2048
• DOI: 10.1007/BF01258678

The wild-type and three deletional interposon mutants (psaE, ndhF, psaE/ndhF) of Synechococcus sp. PCC7002 were analysed with respect to their ability to induce the CO2-concentrating mechanism (CCM). The response of the ndhF mutant was similar to that of the control with normal adaptation of CO2 and $\mathrm{H}\mathrm{C}{\mathrm{O}}_{3}^{-}$ transport at low CO2. In contrast, the psaE mutant was unable to grow normally at 20 μL·L-1 and could not induce high-affinity $\mathrm{H}\mathrm{C}{\mathrm{O}}_{3}^{-}$ uptake. The double mutant showed an even greater degree of impaired growth than the psaE mutant, even at 350 μL·L-1 CO2. It also showed a relatively specific defect in the ability of the cells to induce high-affinity $\mathrm{H}\mathrm{C}{\mathrm{O}}_{3}^{-}$-uptake, although when growth was severely restricted at 20 μL·L-1 CO2 there may also have been some effect on the induction of CO2 transport. Our results indicate a key role for psaE-mediated, and to a lesser extent ndhF-mediated, electron transport in efficient utilisation of $\mathrm{H}\mathrm{C}{\mathrm{O}}_{3}^{-}$ under low inorganic carbon in Synechococcus sp. PCC7002.