Abstract
Suspensions of mesophyll cells, prepared from tobacco leaves by treatment with pectinase, fixed CO2 by photosynthesis. The products of carbon assimilation were similar for both cells and intact tissue. The cells sustained a constant fixation rate for 20 to 25 hours. For optimal CO2 fixation, enzymatic maceration of the tissue was accomplished in 0.8 m sorbitol, but photosynthesis was optimal in 0.6 m sorbitol at pH 7 to 7.5. A hypertonic environment during maceration, which results in cell plasmolysis, is essential to maintain intact plasmalemmas and hence photosynthetically active cells. For sustained CO2 fixation, light intensities below 500 foot-candles were required. Higher light intensities (to 1000 foot-candles) gave high initial rates of CO2 fixation, but the cells bleached and were inactive on prolonged incubation. At pH 7.0 the bicarbonate concentration at maximal velocity of CO2 fixation was about 1.5 mm and the apparent Km for bicarbonate was 0.2 mm.
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- CRELIN E. S. Mitosis in adult cartilage. Science. 1957 Apr 5;125(3249):650–650. doi: 10.1126/science.125.3249.650. [DOI] [PubMed] [Google Scholar]
- Francki R. I., Zaitlin M., Jensen R. G. Metabolism of Separated Leaf Cells: II. Uptake and Incorporation of Protein and Ribonucleic Acid Precursors by Tobacco Cells. Plant Physiol. 1971 Jul;48(1):14–18. doi: 10.1104/pp.48.1.14. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Jensen R. G., Bassham J. A. Photosynthesis by isolated chloroplasts. Proc Natl Acad Sci U S A. 1966 Oct;56(4):1095–1101. doi: 10.1073/pnas.56.4.1095. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Usui H., Takebe I. Division and growth of single mesophyll cells isolated enzymatically from tobacco leaves. Dev Growth Differ. 1969 Oct;11(2):143–151. doi: 10.1111/j.1440-169x.1969.00143.x. [DOI] [PubMed] [Google Scholar]
- Zaitlin M., Coltrin D. Use of Pectic Enzymes in a Study of the Nature of Intercellular Cement of Tobacco Leaf Cells. Plant Physiol. 1964 Jan;39(1):91–95. doi: 10.1104/pp.39.1.91. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Zelitch I. Increased rate of net photosynthetic carbon dioxide uptake caused by the inhibition of glycolate oxidase. Plant Physiol. 1966 Dec;41(10):1623–1631. doi: 10.1104/pp.41.10.1623. [DOI] [PMC free article] [PubMed] [Google Scholar]