caa a22 4500 397522355 CHVBK 20180308164636.0 cr unu---uuuuu 161202e199509 xx s 000 0 eng 10.1093/jxb/46.special_issue.1277 doi (NATIONALLICENCE)oxford-10.1093/jxb/46.special_issue.1277 Regulation of ribulose 1,5-bisphosphate carboxylase/oxygenase by metabolites [Elektronische Daten] [Jerome C. Servaites, Donald R. Geiger] Ribulose 1,5-bisphosphate carboxylase/oxygenase (Rubisco) and other enzymes and their common metabolites form a system regulated by feedforward and feedback mechanisms that is directly involved in assimilation of carbon. The interaction of these components in the chloroplast gives rise to properties, which can not be predicted from the study of isolated components alone. Experiments were conducted to explain how the observed pattern of system level regulation is consistent with the individual characteristics of Rubisco measured in vitro. In vitro Rubisco is responsive to a wide range of ribulose 1,5-bisphosphate and phosphoglycerate concentrations, similar to those found in leaves under field conditions. Metabolite regulation of carbon assimilation in vivo involves several processes. Among these are negative co-operativity of ribulose 1,5-bisphosphate binding by Rubisco, competitive inhibition of Rubisco by phosphoglycerate and inorganic phosphate, a high Rubisco active site concentration in the chloroplast, and maintenance of a constant phosphate concentration in the chloroplast resulting in reciprocal changes in the concentrations of ribulose 1,5-bisphosphate, phosphoglycerate and inorganic phosphate. High-light-grown plants exhibited higher assimilation rates than those growing under moderate light levels, but had similar Rubisco concentrations. Larger ribulose 1,5-bisphosphate/phosphoglycerate ratios in plants grown outdoors are responsible for the higher Rubisco activities and greater rates of carbon fixation observed under these conditions. © 1995 Oxford University Press Photosynthetic Carbon Reduction nationallicence Self-regulation nationallicence 3-phosphoglyceric acid nationallicence photosynthesis nationallicence Servaites Jerome C. Department of Biology, University of Dayton, Dayton, OH 45469-2320, USA aut Geiger Donald R. Department of Biology, University of Dayton, Dayton, OH 45469-2320, USA aut Journal of Experimental Botany Oxford University Press 46/special_issue(1995-09), 1277-1283 0022-0957 46:special_issue<1277 1995 46 exbotj https://doi.org/10.1093/jxb/46.special_issue.1277 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1093/jxb/46.special_issue.1277 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Servaites Jerome C. Department of Biology, University of Dayton, Dayton, OH 45469-2320, USA aut NATIONALLICENCE 700 1- Geiger Donald R. Department of Biology, University of Dayton, Dayton, OH 45469-2320, USA aut NATIONALLICENCE 773 0- Journal of Experimental Botany Oxford University Press 46/special_issue(1995-09), 1277-1283 0022-0957 46:special_issue<1277 1995 46 exbotj Metadata rights reserved CC BY-NC-4.0 http://creativecommons.org/licenses/by-nc/4.0 nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-oxford