Mutants of synechocystis PCC6803 defective in inorganic carbon transport

Journal Article · Mon Oct 01 04:00:00 EDT 1990 · Plant Physiology; (USA)

DOI:https://doi.org/10.1104/pp.94.2.760· OSTI ID:5914955

Ogawa, Teruo ^[1]

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1. Institute of Physical and Chemical Research, Saitama (Japan)

Eighty mutants of Synechocystis PCC6803 that require high CO{sub 2} for growth were examined with a mass spectrometer for their ability to take up CO{sub 2} in the light. Two of these mutants (type A) did not show any CO{sub 2} uptake while the rest of the mutants (type B) took up CO{sub 2} actively. Type A mutants (RKa and RKb) and one type B mutant (RK11) were partially characterized. At 3% CO{sub 2}, growth rates of the mutants and the wild type (WT) were similar. Under air levels of CO{sub 2}, growth of RKa and RKb was very slow, and RK11 did not grow at all. The photosynthetic affinities for inorganic carbon (C{sub i}) in these three mutants were about 100 times lower than the affinity in WT. The following characteristics of type A mutants indicated that the mutants have a defect in their CO{sub 2}-transport system: (a) the activity of {sup 13}C{sup 18}O{sub 2} uptake in RKa and RKb in the light was less than 5% the activity in WT, and (b) each mutant had only a low level of activity of {sup 14}CO{sub 2} uptake as measured by the method of silicone oil-filtering centrifugation. The HCO{sub 3}{sup {minus}}-transport system was also impaired in these mutants. The activity of H{sup 14}CO{sub 3}{sup {minus}} uptake was negligibly low in RKb and was one-third the activity of WT in RKa. On the other hand, the type B mutant, RK11, transported CO{sub 2} and HCO{sub 3}{sup {minus}} into the intracellular C{sub i} pool as actively as WT but was unable to utilize it for photosynthesis. Complementation analysis of type A mutants indicated that RKa and RKb have mutations in different regions of the genome.

• OSTI ID: 5914955
• Journal Information: Plant Physiology; (USA), Journal Name: Plant Physiology; (USA) Vol. 94:2; ISSN 0032-0889; ISSN PLPHA
• Country of Publication: United States
• Language: English

Related Subjects

551001* -- Physiological Systems-- Tracer Techniques
59 BASIC BIOLOGICAL SCIENCES
CARBON 13
CARBON COMPOUNDS
CARBON DIOXIDE
CARBON DIOXIDE FIXATION
CARBON ISOTOPES
CARBON OXIDES
CHALCOGENIDES
CHEMICAL REACTIONS
CYANOBACTERIA
EVEN-EVEN NUCLEI
EVEN-ODD NUCLEI
ISOTOPE APPLICATIONS
ISOTOPES
LIGHT NUCLEI
MASS SPECTROSCOPY
MICROORGANISMS
MUTANTS
NUCLEI
OXIDES
OXYGEN 18
OXYGEN COMPOUNDS
OXYGEN ISOTOPES
PHOTOCHEMICAL REACTIONS
PHOTOSYNTHESIS
SPECTROSCOPY
STABLE ISOTOPES
SYNTHESIS
TRACER TECHNIQUES