New Phytologist, Feb, 2011, Vol.189, p.659(19)
To authenticate to the full-text of this article, please visit this link: http://dx.doi.org/10.1111/j.1469-8137.2010.03576.x Byline: Jorg Kruse (1), Heinz Rennenberg (1), Mark A. Adams (2) Keywords: acclimatization; Arrhenius kinetics; Q-model; respiration; temperature response Abstract: Contents Summary Temperature crucially affects the speed of metabolic processes in poikilotherm organisms, including plants. The instantaneous temperature responses of O.sub.2-reduction and CO.sub.2-release can be approximated by Arrhenius kinetics, even though respiratory gas exchange of plants is the net effect of many constituent biochemical processes. Nonetheless, the classical Arrhenius equation must be modified to account for a dynamic response to measurement temperatures. We show that this dynamic response is readily explained by combining Arrhenius and Michaelis-Menten kinetics, as part of a fresh appraisal of metabolic interpretations of instantaneous temperature responses. In combination with recent experimental findings, we argue that control of mitochondrial electron flow is shared among cytochrome oxidase and alternative oxidase under in vivo conditions, and is continuously coordinated. In this way, upstream carbohydrate metabolism and downstream electron transport appear to be optimized according to the demand of ATP, TCA-cycle intermediates and anabolic reducing power under differing metabolic states. We provide a link to the 'Growth and Maintenance Paradigm' of respiration and argue that respiratory temperature responses can be used as a tool to probe metabolic states of plant tissue, such that we can learn more about the mechanisms that govern longer-term acclimatization responses of plant metabolism. Author Affiliation: (1)Institute of Forest Botany, Chair of Tree Physiology, Albert-Ludwigs-University Freiburg, Georges-Koehler-Allee 53-54, D-79110 Freiburg, Germany (2)Faculty of Agriculture, Food and Natural Resources, The University of Sydney, Sydney, NSW 2006, Australia Article History: Received: 6 July 2010, Accepted: 29 October 2010 Article note: Author for correspondence:, Jorg Kruse, Tel: +49 (0) 761 203 8300, Fax: +49 (0) 761 203 8302, Email: firstname.lastname@example.org
Carbohydrate Metabolism -- Physiological Aspects ; Cytochrome Oxidase -- Physiological Aspects
Cengage Learning, Inc.