Summary
Mesophyll protoplasts and bundle-sheath cells of Pennisetum purpureum Schum., a C4 plant with low phenol-oxidase activity, were enzymatically separated according to methods recently developed with sugarcane (Saccharum officinarum L.), maize (Zea mays L.), and sorghum (Sorghum bicolor L.). The phosphoenolpyruvate carboxylase and NADP-malic dehydrogenase of the C4 pathway were found to be localized in the mesophyll protoplasts while ribulose-1,5-diphosphate (RuDP) carboxylase, phosphoribulokinase and NADP-malic enzyme were localized in the bundle-sheath cells. The levels of these enzyme activities in the leaf extracts and in certain cellular preparations of P. purpureum are sufficient to account for the rate of photosynthesis in the leaf. These results on the activities and distribution of photosynthetic enzymes with P. purpureum preparations are consistent with our previous evidence for cellular separation of the C4 and the reductive pentose-phosphate pathways in C4 species.
With chlorogenic acid as the substrate, P. purpureum, Setaria lutescens (Weigel) Hubb. and Panicum texanum Buckl. have relatively low phenol-oxidase activity, similar to that found in spinach (Spinacia oleracea L.); while sorghum, sugarcane, maize, Panicum capillare L. and P. miliaceum L. have relatively high phenoloxidase activity, similar to that in tobacco (Nicotiana tabacum L.). C4 species having high phenol-oxidase activity have substantial activity of the enzyme in both mesophyll and bundle-sheath extracts. Since phenol oxidase is found in both cell types it is not logical to expect preferential inhibition of RuDP carboxylase or other photosynthetic enzymes through phenol oxidation in mesophyll extracts, as has been previously suggested. When dithiothreitol and polyvinylpyrrolidone were included in the enzyme extraction medium, the activity of RuDP carboxylase increased 10% in P. purpureum and 59% in sugarcane leaf extracts.
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Andrews, T. J., Johnson, H. S., Slack, R. C., Hatch, M. D.: Malic enzyme and aminotransferases in relation to 3-phosphoglycerate formation in plants with the C4-dicarboxylic acid pathway of photosynthesis. Phytochemistry 10, 2005–2013 (1971)
Baldry, C. W., Bucke, C., Coombs, J.: Effects of some phenoloxidase inhibitors on chloroplasts and carboxylating enzymes of sugarcane and spinach. Planta (Berl.) 94, 124–133 (1970a)
Baldry, C. W., Bucke, C., Coombs, J.: Progressive release of carboxylating enzymes during mechanical grinding of sugarcane leaves. Planta (Berl.) 97, 310–319 (1971)
Baldry, C. W., Bucke, C., Coombs, J., Gross, D.: Phenols, phenoloxidase and photosynthetic activity of chloroplasts isolated from sugarcane and spinach. Planta (Berl.) 94, 107–123 (1970b)
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)
Bucke, C., Long, S. P.: Location of enzymes assimilating and shuttling carbon dioxide in sugarcane and maize leaf tissue. In: Proc. II Internat. Congr. Photosynthesis Research, vol. 3, p. 1935–1941, Forti, G., Avron, M., Melandri, A., eds. The Hague: Junk 1972
Chen, T. M., Brown, R. H., Black, C. C.: Photosynthetic CO2 fixation products and activities of enzymes related to photosynthesis in bermudagrass and other plants. Plant Physiol. 47, 199–203 (1971)
Chen, T. M., Campbell, W. H., Dittrich, P., and Black, C. C.: Distribution of carboxylation and decarboxylation enzymes in isolated mesophyll cells and bundle sheath strands of C4 plants. Biochem. biophys. Res. Commun. 51, 461–467 (1973)
Coombs, J.: The potential of higher plants with the phosphopyruvic acid cycle. Proc. roy. Soc. B 179, 221–235 (1971)
Coombs, J., Baldry, C. W.: The C-4 pathway in Pennisetum purpureum. Nature (Lond.) 238, 268–270 (1972)
Coombs, J., Baldry, C. W., Bucke, C.: The C-4 pathway in Pennisetum purpureum. I. The allosteric nature of PEP carboxylase. Planta (Berl.) 110, 95–107 (1973a)
Coombs, J., Baldry, C. W., Bucke, C.: The C-4 pathway in Pennisetum purpureum. II. Malate dehydrogenase and malic enzyme. Planta (Berl.) 110, 109–120 (1973b)
Coombs, J., Baldry, C. W., Brown, J. E.: The C-4 pathway in Pennisetum purpureum III. Structure and photosynthesis. Planta (Berl.) 110, 121–129 (1973c)
Edwards, G. E., Gutierrez, M.: Metabolic activities in extracts of mesophyll and bundle sheath cells of Panicum miliaceum (L.) in relation to the C dicarboxylic acid pathway of photosynthesis. Plant Physiol. 50, 728–732 (1972)
Edwards, G. E., Lee, S. S., Chen, T. M., Black, C. C.: Carboxylation reactions and photosynthesis of carbon compounds in isolated mesophyll and bundle sheath cells of Digitaria sanguinalis (L.) Scop. Biochem. biophys. Res. Commun. 39, 389–395 (1970)
Gutierrez, M., Kanai, R., Huber, S. C., Ku, S. B., Edwards, G. E.: Photosynthesis in mesophyll protoplasts and bundle sheath cells of C4 plants. I. Carboxylases and CO2 fixation studies. Z. Pflanzenphysiol. 72, 305–319 (1974)
Kanai, R., Edwards, G. E.: Enzymatic separation of mesophyll protoplasts and bundle sheath cells from leaves of C4 plants. Naturwissenschaften 60, 157–158 (1973a)
Kanai, R., Edwards, G. E.: Separation of mesophyll protoplasts and bundle sheath cells from maize leaves for photosynthetic studies. Plant Physiol. 51, 1133–1137 (1973b)
Kanai, R., Edwards, G. E.: Purification of enzymatically isolated mesophyll protoplasts from C3, C4, and Crassulacean Acid Metabolism plants using an aqueous dextran-polyethylene glycol two-phase system. Plant Physiol. 52, 484–490 (1973c)
Latzko, E., Garnier, R., Gibbs, M.: Effect of photosynthesis, photosynthetic inhibitors, and oxygen on the activity of ribulose 5-phosphate kinase. Biochem. biophys. Res. Commun. 39, 1140–1144 (1970)
Latzko, E., Gibbs, M.: Enzyme activities of the carbon reduction cycle in some photosynthetic organisms. Plant Physiol. 44, 295–300 (1969)
Slack, C. R., Hatch, M. D.: Comparative studies on the activity of carboxylases and other enzymes in relation to the new pathway of photosynthetic carbon dioxide fixation in tropical grasses. Biochem. J. 103, 660–665 (1967)
Wintermans, J. F. G. M., De Mots, A.: Spectrophotometric characteristics of chlorophyll and their pheophytins in ethanol. Biochim. biophys. Acta (Amst.) 109, 448–453 (1965)
Woo, K. C., Pyliotis, N. A., Downton, W. J. S.: Thylakoid aggregation and chlorophyll a/chlorophyll b ratio in C4-plants. Z. Pflanzenphysiol. 64, 400–413 (1971)
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Ku, S.B., Gutierrez, M. & Edwards, G.E. Localization of the C4 and C3 pathways of photosynthesis in the leaves of Pennisetum purpureum and other C4 species. Insignificance of phenol oxidase. Planta 119, 267–278 (1974). https://doi.org/10.1007/BF00388330
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DOI: https://doi.org/10.1007/BF00388330