Abstract
Using a novel screening procedure, we have selected a new class of mutant from the cyanobacterium Synechococcus PCC7942 that fails to adapt to growth at an extremely low inorganic carbon (Ci) concentration. The mutant (Tm17) reported in this study grows normally at or above air levels of CO2 (340 [mu]L L-1) but does not survive at 20 [mu]L L-1 CO2 in air. Air-grown Tm17 cells showed properties similar to wild-type cells in various aspects of the CO2-concentrating mechanism examined. Following transfer from air levels to 20 [mu]L L-1 CO2, however, the mutant cells failed to increase their photosynthetic affinity for Ci. This results in an approximately 10-fold difference in photosynthetic affinity between the wild-type and Tm17 cells under Ci-limiting conditions [the K0.5(Ci) values were 11 and 136 [mu]M, respectively]. Further examination of factors possibly contributing to this low photosynthetic affinity showed that Tm17 cells have no inducible high-affinity HCO3- transport and do not appear to show induction of increased carboxysomal carbonic anhydrase and ribulose-1,5-bisphosphate carboxylase/oxygenase activities. It appears that a common factor, possibly relating to CO2 detection and/or induction signal, or the HCO3-transport mechanism may have been impaired in the mutant. Complementation results indicate that the mutation responsible for the phenotype has occurred in an 8- to 10-kb EcoRI genomic DNA fragment.
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Selected References
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- Badger M. R., Andrews T. J. Photosynthesis and Inorganic Carbon Usage by the Marine Cyanobacterium, Synechococcus sp. Plant Physiol. 1982 Aug;70(2):517–523. doi: 10.1104/pp.70.2.517. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Dzelzkalns V. A., Owens G. C., Bogorad L. Chloroplast promoter driven expression of the chloramphenicol acetyl transferase gene in a cyanobacterium. Nucleic Acids Res. 1984 Dec 11;12(23):8917–8925. doi: 10.1093/nar/12.23.8917. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Fukuzawa H., Suzuki E., Komukai Y., Miyachi S. A gene homologous to chloroplast carbonic anhydrase (icfA) is essential to photosynthetic carbon dioxide fixation by Synechococcus PCC7942. Proc Natl Acad Sci U S A. 1992 May 15;89(10):4437–4441. doi: 10.1073/pnas.89.10.4437. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Marcus Y., Harel E., Kaplan A. Adaptation of the Cyanobacterium Anabaena variabilis to Low CO(2) Concentration in Their Environment. Plant Physiol. 1983 Jan;71(1):208–210. doi: 10.1104/pp.71.1.208. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Marcus Y., Zenvirth D., Harel E., Kaplan A. Induction of HCO(3) Transporting Capability and High Photosynthetic Affinity to Inorganic Carbon by Low Concentration of CO(2) in Anabaena variabilis. Plant Physiol. 1982 May;69(5):1008–1012. doi: 10.1104/pp.69.5.1008. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Mayo W. P., Williams T. G., Birch D. G., Turpin D. H. Photosynthetic Adaptation by Synechococcus leopoliensis in Response to Exogenous Dissolved Inorganic Carbon. Plant Physiol. 1986 Apr;80(4):1038–1040. doi: 10.1104/pp.80.4.1038. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Price G. D., Coleman J. R., Badger M. R. Association of Carbonic Anhydrase Activity with Carboxysomes Isolated from the Cyanobacterium Synechococcus PCC7942. Plant Physiol. 1992 Oct;100(2):784–793. doi: 10.1104/pp.100.2.784. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Scanlan D. J., Bloye S. A., Mann N. H., Hodgson D. A., Carr N. G. Construction of lacZ promoter probe vectors for use in Synechococcus: application to the identification of CO2-regulated promoters. Gene. 1990 May 31;90(1):43–49. doi: 10.1016/0378-1119(90)90437-v. [DOI] [PubMed] [Google Scholar]
- Volokita M., Zenvirth D., Kaplan A., Reinhold L. Nature of the Inorganic Carbon Species Actively Taken Up by the Cyanobacterium Anabaena variabilis. Plant Physiol. 1984 Nov;76(3):599–602. doi: 10.1104/pp.76.3.599. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Wintermans J. F., de Mots A. Spectrophotometric characteristics of chlorophylls a and b and their pheophytins in ethanol. Biochim Biophys Acta. 1965 Nov 29;109(2):448–453. doi: 10.1016/0926-6585(65)90170-6. [DOI] [PubMed] [Google Scholar]
- Yu J. W., Price G. D., Song L., Badger M. R. Isolation of a Putative Carboxysomal Carbonic Anhydrase Gene from the Cyanobacterium Synechococcus PCC7942. Plant Physiol. 1992 Oct;100(2):794–800. doi: 10.1104/pp.100.2.794. [DOI] [PMC free article] [PubMed] [Google Scholar]