Abstract
Spirodela oligorrhiza plants were used to study direct effects of light on plastid gene expression uncoupled from sequential chloroplast-developmental processes. Specific transcript levels were analysed using chloroplast, gene-fragment probes. Protein synthesis in vivo and in vitro was also measured. In tissue with mature chloroplasts, light/dark regimes had no substantial effect on transcript levels of the psbA gene coding for the 32-kd protein. However, under the same conditions, synthesis of the protein itself was dramatically affected. We conclude that in mature chloroplasts synthesis of 32-kd protein is regulated mainly at a translational level. Transcript levels of the rbcL gene, coding for the large subunit of ribulosebisphosphate carboxylase-oxygenase, were somewhat sensitive to light/dark effects, although not to the same degree as was synthesis of the protein. We conclude that translational events and transcript levels are involved in regulating synthesis of this polypeptide. Carbon deprivation in the dark reduced psbA and rbcL transcript levels appreciably below those found in non-starved, dark-grown tissue. This suggests that starvation and dark effects must be experimentally separated from each other for valid conclusions to be drawn about light/dark regulation of chloroplast gene expression.
Keywords: messenger RNA, ribulosebisphosphate carboxylase-oxygenase, Spirodela oligorrhiza, translational control
Full text
PDF




Images in this article
Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- Bedbrook J. R., Link G., Coen D. M., Bogorad L. Maize plastid gene expressed during photoregulated development. Proc Natl Acad Sci U S A. 1978 Jul;75(7):3060–3064. doi: 10.1073/pnas.75.7.3060. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Broglie R., Coruzzi G., Fraley R. T., Rogers S. G., Horsch R. B., Niedermeyer J. G., Fink C. L., Chua N. H. Light-regulated expression of a pea ribulose-1,5-bisphosphate carboxylase small subunit gene in transformed plant cells. Science. 1984 May 25;224(4651):838–843. doi: 10.1126/science.6719112. [DOI] [PubMed] [Google Scholar]
- Crossland L. D., Rodermel S. R., Bogorad L. Single gene for the large subunit of ribulosebisphosphate carboxylase in maize yields two differentially regulated mRNAs. Proc Natl Acad Sci U S A. 1984 Jul;81(13):4060–4064. doi: 10.1073/pnas.81.13.4060. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Fluhr R., Fromm H., Edelman M. Clone bank of Nicotiana tabacum chloroplast DNA: mapping of the alpha, beta and epsilon subunits of the ATPase coupling factor, the large subunit of ribulosebisphosphate carboxylase, and the 32-kDal membrane protein. Gene. 1983 Nov;25(2-3):271–280. doi: 10.1016/0378-1119(83)90231-7. [DOI] [PubMed] [Google Scholar]
- Glisin V., Crkvenjakov R., Byus C. Ribonucleic acid isolated by cesium chloride centrifugation. Biochemistry. 1974 Jun 4;13(12):2633–2637. doi: 10.1021/bi00709a025. [DOI] [PubMed] [Google Scholar]
- Hoffman-Falk H., Mattoo A. K., Marder J. B., Edelman M., Ellis R. J. General occurrence and structural similarity of the rapidly synthesized, 32,000-dalton protein of the chloroplast membrane. J Biol Chem. 1982 Apr 25;257(8):4583–4587. [PubMed] [Google Scholar]
- Link D. P., Lantz B. M. Vasodilator response in the lower extremity induced by contrast medium. I Canine model. Acta Radiol Diagn (Stockh) 1982;23(2):81–86. doi: 10.1177/028418518202300201. [DOI] [PubMed] [Google Scholar]
- Marder J. B., Goloubinoff P., Edelman M. Molecular architecture of the rapidly metabolized 32-kilodalton protein of photosystem II. Indications for COOH-terminal processing of a chloroplast membrane polypeptide. J Biol Chem. 1984 Mar 25;259(6):3900–3908. [PubMed] [Google Scholar]
- Mattoo A. K., Hoffman-Falk H., Marder J. B., Edelman M. Regulation of protein metabolism: Coupling of photosynthetic electron transport to in vivo degradation of the rapidly metabolized 32-kilodalton protein of the chloroplast membranes. Proc Natl Acad Sci U S A. 1984 Mar;81(5):1380–1384. doi: 10.1073/pnas.81.5.1380. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Pelham H. R., Jackson R. J. An efficient mRNA-dependent translation system from reticulocyte lysates. Eur J Biochem. 1976 Aug 1;67(1):247–256. doi: 10.1111/j.1432-1033.1976.tb10656.x. [DOI] [PubMed] [Google Scholar]
- Roberts B. E., Paterson B. M. Efficient translation of tobacco mosaic virus RNA and rabbit globin 9S RNA in a cell-free system from commercial wheat germ. Proc Natl Acad Sci U S A. 1973 Aug;70(8):2330–2334. doi: 10.1073/pnas.70.8.2330. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Sasaki Y., Sakihama T., Kamikubo T., Shinozaki K. Phytochrome-mediated regulation of two mRNAs, encoded by nuclei and chloroplasts of ribulose-1,5-bisphosphate carboxylase/oxygenase. Eur J Biochem. 1983 Jul 1;133(3):617–620. doi: 10.1111/j.1432-1033.1983.tb07507.x. [DOI] [PubMed] [Google Scholar]
- Smith S. M., Ellis R. J. Light-stimulated accumulation of transcripts of nuclear and chloroplast genes for ribulosebisphosphate carboxylase. J Mol Appl Genet. 1981;1(2):127–137. [PubMed] [Google Scholar]
- Thomas P. S. Hybridization of denatured RNA and small DNA fragments transferred to nitrocellulose. Proc Natl Acad Sci U S A. 1980 Sep;77(9):5201–5205. doi: 10.1073/pnas.77.9.5201. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Tobin E. M. Light regulation of specific mRNA species in Lemna gibba L. G-3. Proc Natl Acad Sci U S A. 1978 Oct;75(10):4749–4753. doi: 10.1073/pnas.75.10.4749. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Tobin E. M., Suttie J. L. Light Effects on the Synthesis of Ribulose-1,5-Bisphosphate Carboxylase in Lemna gibba L. G-3. Plant Physiol. 1980 Apr;65(4):641–647. doi: 10.1104/pp.65.4.641. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Walden R., Leaver C. J. Synthesis of Chloroplast Proteins during Germination and Early Development of Cucumber. Plant Physiol. 1981 Jun;67(6):1090–1096. doi: 10.1104/pp.67.6.1090. [DOI] [PMC free article] [PubMed] [Google Scholar]



