This Article Full Text (PDF) A correction has been published Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via CrossRef Citing Articles via Google Scholar Google Scholar Articles by Selinioti, E. Articles by Gavalas, N. A. Search for Related Content PubMed PubMed Citation Articles by Selinioti, E. Articles by Gavalas, N. A. Agricola Articles by Selinioti, E. Articles by Gavalas, N. A.

Articles

Cooperative Effects of Light and Temperature on the Activity of Phosphoenolpyruvate Carboxylase from Amaranthus paniculatus L. ¹

Department of Biology, University of Patras, Patras, Greece, Laboratory of Plant Physiology, University of Patras, Patras, Greece

The phosphoenolpyruvate carboxylase of Amaranthus paniculatus shows in vitro optimum affinity (S_0.5) to phosphoenolpyruvate at a relatively high temperature (about 35°C); even in the presence of activators, it functions efficiently only above 25 to 27°C. At lower temperatures, a steep increase of activity with temperature is observed, due to the high activation energy for the catalyzed reaction. The same behavior in vivo could amplify the photoactivation of the enzyme to a large extent, since the night/day transition is soon followed by a considerable rise in leaf temperature.

¹ Supported by the State Scholarship Foundation (Greece) through a scholarship to E. S. The final experimental stage was also supported financially through a Grant from the Ministry of Research and Technology.

This article has been cited by other articles:

				B. Chinthapalli, J. Murmu, and A. S. Raghavendra Dramatic difference in the responses of phosphoenolpyruvate carboxylase to temperature in leaves of C3 and C4 plants J. Exp. Bot., February 1, 2003; 54(383): 707 - 714. [Abstract] [Full Text] [PDF]