Summary
The photosynthetic products of Portulaca oleracea differ greatly depending on leaf age and length of exposure to 14CO2. Mature leaves of P. oleracea fix 14CO2 primarily into organic and amino acids during a 10-s exposure period. Less than 2% of the 14CO2 fixed appears in phosphorylated compounds. In contrast, incorporation into amino acids can account for over 60% of the total 14CO2 fixed by young leaves in an equal time period, and incorporation into alanine alone can account for up to one half of this amount. Senescent leaves display a quantitative shift of primary products toward phosphorylated compounds with a concomitant reduction of the label residing in malate and asparate. About 8 times more phosphoglyceric acid is produced in senescent leaves than in mature leaves. The aspartate/ malate ratio is not constant and depends on the length of time the leaves are exposed to 14CO2 and the age of the leaves under study. It appears as if the stage of leaf development is one of the most important factors determining the operation of a particular enzyme system in C4 plants.
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References
Arnon, D. I.: Copper enzymes in isolated chloroplasts. Polyphenol oxidase in Beta vulgaris. Plant Physiol. 24, 1–15 (1949)
Baddeley, M. S.: Biochemical aspects of senescence. In: Ecology of leaf surface micro-organisms, p. 415–429, Preece, T. F., Dickson, C. H., eds. London: Acad. Press 1971
Baldry, C. W., Bucke, C., Coombs, J.: Progressive release of carboxylating enzymes during mechanical grinding of sugar cane leaves. Planta (Berl.) 97, 310–319 (1971)
Barton, R.: Fine structure of mesophyll cells in senescing leaves of Phaseolus. Planta (Berl.) 71, 314–325 (1966)
Black, C. C., Mayne, B. C.: P700 activity and chlorophyll content of plants with different photosynthetic carbon dioxide fixation cycles. Plant Physiol. 45, 738–741 (1970)
Black, C. C.: Ecological implications of dividing plants into groups with distinct photosnthetic production capacities. Advanc. Ecol. Res. 7, 87–113 (1971)
Bradbeer, J. W., Ranson, S. L., Stiller, M.: Malate synthesis in crassulacean leaves. I. The distribution of 14C in malate of leaves exposed to 14CO2 in the dark. Plant Physiol. 33, 66–70 (1958)
Bucke, C., Long, S. P.: Release of carboxylating enzymes from maize and sugar cane leaf tissue during progressive grinding. Planta (Berl.) 99, 199–210 (1971)
Chang, F. H., Troughton, J. H.: Chlorophyll a/b ratios in C3- and C4-plants. Photosynthetica 6, 57–65 (1972)
Chen, T. M., Brown, R. H., Black, C. C., Jr.: Photosnthetic 14CO2 fixation products and activities of enzymes related to photosynthesis in Bermuda grass and other plants. Plant Physiol. 47, 199–203 (1971)
Coombs, J., Baldry, C. W., Bucke, C.: The C4 pathway in Pennisetum purpureum I. The allosteric nature of PEP carboxylase. Planta (Berl.) 110, 95–107 (1973)
Dickmann, D. I.: chlorophyll, ribulose-1, 5-diphosphate carboxylase, and Hill reaction activity in developing leaves of Populus deltoides. Plant Physiol. 48, 143–145 (1971)
Downton, W. J. S.: Preferential C4-dicarboxylic acid synthesis, the postillumination CO2 burst, casrboxyl transfer step, and grana configuration in plants with C4 photosynthesis. Canad. J. Bot. 48, 1795–1800 (1970)
Downton, W. J. S.: Further evidence for two modes of carboxyl transfer in plants with C4 photosynthesis. Canad. J. Bot. 49, 1439–1442 (1971)
Hatch, M. D., Slack, C. R.: Photosynthesis in sugar cane leaves. Biochem. J. 101, 103–111 (1966)
Hatch, H. D., Slack, C. R., Johnson, H. S.: Further studies in a new pathway of photosynthetic carbon dioxide fixation in sugar cane and its occurrence in other plant species. biochem. J. 102, 417–422 (1967)
Holden, M.: Chloroplast pigments in plants with the C4-dicarboxylic acid pathway of photosynthesis. Photosynthetica 7, 41–49 (1973)
Khanna, R., Sinha, S. K.: change in predominance from C4 to C3 pathway following anthesis in Sorghum. Biochim. biophys. Res. Commun. 52, 121–124 (1973)
Kortschak, H. P., Hartt, C. E., Burr, G.: Carbon dioxide fixation in sugar cane leaves. Plant Physiol. 40, 209–213 (1965)
Kunitake, G., Stitt, C., Saltman, P.: Dark fixation of CO2 by tobacco leaves. Plant Physiol. 34, 123–126 (1959)
Laetsch, W. M.: Chloroplast specialization in dicotyledons possessing the C4-dicarboxylic acid pathway of photosynthetic CO2 fixation. Amer. J. Bot. 55, 875–883 (1968)
Laetsch, W. M.: Relationship between chloroplast structure and photosynthetic carbon-fixation pathways. Sci. Prog. (Oxf.) 57, 323–351 (1969)
Laetsch, W. M.: Chloroplast structural relationships in leaves of C4 plants. In: Photosynthesis and photorespiration, p. 323–349, Hatch, M. D., Osmond, C. B., Slayter, R. O., eds. New York: Wiley-Interscience 1971
Laetsch, W. M., Kortschak, H. P.: Chloroplast structure and function in tissue cultures of a C4 plant. Plant Physiol. 49, 1021–1023 (1972)
Nygaard, P.: Two-way separation of carboxylic acids by thin-layer electrophoresis and chromatography. J. Chromatog. 30, 240–243 (1967)
O'Neal, D., Hew, C. S., Latzko, E., Gibbs, M.: Photosynthetic carbon metabolism of isolated corn chloroplasts. Plant Physiol. 49, 607–614 (1972)
Pearcy, R. W., Björkman, O.: Hybrids between Atriplex species with and without β-carborcylation photosynthesis: Biochemical characteristics. Carnegie Instn. Yrbk. 69, 632–640 (1971)
Poincelot, R. P.: The distribution of carbonic anhydrase and ribulose diphosphate carboxylase in maize leaves. Plant Physiol. 50, 336–340 (1972)
Schürmann, P.: Separation of phosphate esters and algal extracts by thin-layer electrophoresis and chromatography. J. Chromat. 39, 507–509 (1969)
Schürmann, P., Buchanan, B., Arnon, D. I.: Role of cyclic photophosphorylation in photosynthetic carbon dioxide assimilation by isolated chloroplasts. Biochim. biophys. Acta (Amst.) 267, 111–124 (1971)
Sestak, Z.: Changes in the chlorophyll content as related to photosynthetic activity and age of leaves. Photochem. and Photobiol. 2, 101–110 (1963)
Smith, D. C., Bassham, J. A., Kirk, M.: Dynamics of the photosynthesis of carbon compounds. II. Amino acid synthesis. biochim. biophys. Acta (Amst.) 48, 299–313 (1961)
Stearns, M. E., Wagenaar, E. B.: Ultrastructural changes in chloroplasts of autumn leaves. Canad. J. Genet. Cytol. 13, 550–560 (1971)
Stepka, W., Benson, A. A., Calvin, M.: The path of carbon in photosynthesis. II. Amino acids. Science 108, 304 (1948)
Stetler, D. A., Laetsch, W. M.: Chloroplast development in Nicotiana tabacum “Maryland Mammoth”. Amer. J. Bot. 56, 260–270 (1969)
Ting, I., Dugger, W. M., Jr.: CO2 fixation in Opuntia roots. Plant Physiol. 41, 500–505 (1966)
Turner, N. A., Redgwell, R. J.: A mixed layer for separation of amino acids by thin-layer chromatography. J. Chromatog. 21, 129–132 (1966)
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Kennedy, R.A., Laetsch, W.M. Relationship between leaf development and primary photosynthetic products in the C4 plant Portulaca oleracea L.. Planta 115, 113–124 (1973). https://doi.org/10.1007/BF00387777
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DOI: https://doi.org/10.1007/BF00387777