Photosynthetic carbon metabolism

M. Gibbs and E. Lat2ko, eds.. Photosynthesis 11 Photosynthetic Carbon Metabolism and Kelated Processes, Tnyclopedia of Plant Physiology, N.S., Springer-Vedag, Berlin, 1979. 

Marques, I.A. and L.E. Anderson. 1986. Effects of arsenite, sulfite, and sulfate on photosynthetic carbon metabolism in isolated pea (Pisum sativum L., cv Little Marvel) chloroplasts. Plant Physiol. 82 488-493. 

J. Preiss, C. Levi, in Photosynthesis II, Photosynthetic Carbon Metabolism and Related Processes (M. Gibbs, E. Latzko, Eds.) p. 282, Springer-Verlag, Berlin (1979). 

He suggests that the relative activities of the carboxylase and oxygenase activities of rubisco actually have set, and now maintain, the ratio of C02 to 02 in the earth s atmosphere. Discuss the pros and cons of this hypothesis, in molecular terms and in global terms. How does the existence of C4 organisms bear on the hypothesis [Tolbert, N.E. (1994) The role of photosynthesis and photorespiration in regulating atmospheric C02 and 02. In Regulation of Atmospheric C02 and 02 by Photosynthetic Carbon Metabolism (Tolbert, N.E. Preiss, J., eds), pp. 8-33, Oxford University Press, New York.]... 

Blackwell Science, Malden, MA Fernandez E, Serret P, Demadariaga I, Harbour DS, Davies AG (1992) Photosynthetic carbon metabolism and biochemical composition of spring phytoplankton assemblages enclosed in microcosms the diatom Phaeocystis sp. succession. Mar Ecol Prog Ser 90 89-102 Fogg GE (1983) The ecological significance of extracellular products of phytoplankton photosynthesis. Bot Mar 26 3-14... 

Sikes C. S. and Fabry V. J. (1994) Photosynthesis, CaC03 deposition, coccolithophorids and the global carbon cycle. In Regulation of Atmospheric CO2 and O2 by Photosynthetic Carbon Metabolism (eds. N. E. Tolbert and J. Preiss). Oxford University Press, New York, pp. 217-233. 

O. Holm-Hansen, D.Lubin (1994). Solar ultraviolet radiation effects on rates of CO2 fixation in marine phytoplankton. In N.E. Tolbert, J. Preiss (Eds), Regulation of atmospheric CO2 and O2 by photosynthetic carbon metabolism (pp. 55-74). Oxford University Press, Oxford. 

The major cause of differences in the carbon isotope ratio in plants is closely associated with differences in the pathway of photosynthetic carbon metabolism in the plants, particularly the reaction occurring during the primary carboxylation. 

In order to achieve our objective we are isolating and characterising the coding sequences of key enzymes involved in photosynthetic carbon metabolism and are using these sequences to ... 

As demonstrated earlier (1, 2) the isoprenoid formation is tightly linked to photosynthetic carbon metabolism and 3-PGA PEP pyruvate pathway in developing chloroplasts. The results of isotopic dilution experiments presented in this paper suggest that two independent substrate pools, a pyruvate and an acetate pool, are needed to synthesize the introductory compound of plastidic Mev pathway. 

Clearly there is a need to further investigate the interaction, as well as individual pathways, of the metabolic processes which sustain plant growth under realistic conditions, of both pollutant regime and environment. The Littlehampton open-air fumigation experiment provided the opportunity to assess some enzymes and metabolites of photosynthetic carbon metabolism in leaf material from a commercially grown barley crop. ... 

Effects of SO2 on Photosynthetic Carbon Metabolism in Leaves of Winter Barley (Hordeum vulgare CV. IGRI) 599... 

ScHULZE-SiEBERT, D., A. Heintze, and G. Schultz, Substrate flow from photosynthetic carbon metabolism to chloroplast isopren-oid synthesis in spinach Evidence for a plastidic phosphoglyc-erate mutase, Z. Naturforsch., 42 C, 570-580 (1987). 

Photosynthetic Carbon Metabolism of Olives. J. Sanchez and J.J. Salas. 

Savitch LV, Maxwell DP and Huner NPA. Photosystem II excitation pressure and photosynthetic carbon metabolism in Chlorella vulgaris. Plant Physiol. 1996 111 127-136. 

Kelly, G.J., Latzko,E., Gibbs, M. Regulatory aspects of photosynthetic carbon metabolism. Ann. Rev. Plant Physiol. 27,181-206 (1976)... 

Glycolic acid is a substrate of photorespiration, which mainly occurs in C3 plants. This light-enhanced respiration is recognized as a wasteful process in preventing plants from attaining maximum yield in photosynthesis. A variety of mechanisms have been presented for the formation of glycolic acid from intermediates of photosynthetic carbon metabolism. The most important pathway for the... 

The inhibition of photosynthetic carbon metabolism has not proved to be a fruitful ground for the discovery and development of herbicidal compounds. Consideration of the action and chemistry of enzyme inhibitors, however, could prove to be a profitable exercise for the identification of new herbicidal target sites. 

The fundamental basis of photosynthetic carbon metabolism is the incorporation of carbon dioxide by ribulose-bisphosphate carboxylase (rubisco). This leads to the synthesis of three-carbon sugars which are either exported from the chloroplast or metabolized to regenerate the acceptor ribulose bisphosphate. Rubisco is a bifunctional enzyme in that, in parallel to carboxylation, it catalyzes an oxygenation reaction that leads to phospho-glycolate. This is the starting point for photorespiratory metabolism, which will be discussed below (Section 1.6.2). In C4 plants, the conventional C3 pattern of the photosynthetic carbon reduction Calvin cycle is confined to the bundle sheath cells. The surrounding mesophyll cells act as an ancillary carbon dioxide pump, fixing carbon dioxide via phosphoenolpyruvate carboxylase into C4 acids. These are transported to the bundle sheath for decarboxylation.In this way, photorespiration is limited because of the elevated carbon dioxide levels. 

These complex areas of photosynthetic carbon metabolism could provide considerable potential for the development of specific enzyme inhibitors as herbicides, but to date little success has been achieved. Potential targets will be discussed in relationship to (a) C3 metabolism, (b) photorespiration, and (c) C4 metabolism. 

The study of inhibitors of photosynthetic carbon metabolism has, by contrast, been remarkably unsuccessful. Attempts to design herbicidal inhibitors on rational grounds on the basis of specific enzyme inhibition have not afforded herbicidal compounds that are effective on whole plants. It is possible that in many instances the chloroplast envelope proves to be an insuperable barrier. Nevertheless, recent work identifying specific enzymes such as 5-enolpyruvylshikimate-3-phosphate (EPSP) synthase, acetyl-CoA carboxylase, and acetohydroxy acid synthase has demonstrated the effectiveness of enzyme inhibitors, although none were developed on rational grounds. 

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