Abstract
The pattern of photosynthetic carbon metabolism was determined in tissue cultures of Portulaca oleracea. Four-carbon acids are the most heavily labeled photosynthetic products during short term exposure to 14CO2, containing greater than 40% of the total radioactivity incorporated. Phosphoglyceric acid and sugars account for only 10% of the label after equal exposure times. Other features of the CO2 assimilation pattern in Portulaca callus tissue include a relatively large percentage of label located in various minor products throughout the time course studied, and a greater incorporation of 14C into sugars in tissue cultures than occurs in leaves. Ultrastructurally, the chloroplasts and cells of the callus are like those in the mesophyll cells of Portulaca leaves. The requirement for Kranz anatomy for operation of functional C4 physiology is discussed.
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.
- Arnon D. I. COPPER ENZYMES IN ISOLATED CHLOROPLASTS. POLYPHENOLOXIDASE IN BETA VULGARIS. Plant Physiol. 1949 Jan;24(1):1–15. doi: 10.1104/pp.24.1.1. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Berlyn M. B., Zelitch I. Photoautotrophic growth and photosynthesis in tobacco callus cells. Plant Physiol. 1975 Dec;56(6):752–756. doi: 10.1104/pp.56.6.752. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Hatch M. D., Slack C. R. Photosynthesis by sugar-cane leaves. A new carboxylation reaction and the pathway of sugar formation. Biochem J. 1966 Oct;101(1):103–111. doi: 10.1042/bj1010103. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Kennedy R. A. Photorespiration in c(3) and c(4) plant tissue cultures: significance of kranz anatomy to low photorespiration in c(4) plants. Plant Physiol. 1976 Oct;58(4):573–575. doi: 10.1104/pp.58.4.573. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Kunitake G., Stitt C., Saltman P. Dark Fixation of CO(2) by Tobacco Leaves. Plant Physiol. 1959 Mar;34(2):123–127. doi: 10.1104/pp.34.2.123. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Laetsch W. M., Kortschak H. P. Chloroplast structure and function in tissue cultures of a c(4) plant. Plant Physiol. 1972 Jun;49(6):1021–1023. doi: 10.1104/pp.49.6.1021. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Ting I. P., Dugger W. M. CO(2) Fixation in Opuntia Roots. Plant Physiol. 1966 Mar;41(3):500–505. doi: 10.1104/pp.41.3.500. [DOI] [PMC free article] [PubMed] [Google Scholar]