Trees, 2017, Vol.31(2), pp.623-644
To access, purchase, authenticate, or subscribe to the full-text of this article, please visit this link: http://dx.doi.org/10.1007/s00468-016-1496-0 Byline: Jorg Kruse (1), Mark A. Adams (2), Georgi Kadinov (1), Leila Arab (1), Jurgen Kreuzwieser (1), Saleh Alfarraj (3), Waltraud Schulze (4), Heinz Rennenberg (1,3) Keywords: Arrhenius equation; Acclimation; Temperature; V .sub.cmax; Rubisco activase; Respiration Abstract: Key message Instantaneous temperature responses of leaf respiration and photosynthesis can be described by the same equation, to help understand acclimation of primary metabolism to altered growth temperature and water supply. Abstract We used a three-parameter, modified Arrhenius equation, originally developed for leaf respiration, to characterize A/T curves of Date Palm and acclimation to elevated growth temperature and water deprivation: A.sub.T = A.sub.ref e.sup.[ E.sub.o/ (Ref.sub.A ) ( T - T.sub.ref/ T T.sub.ref ) + [delta].sub.A ( T - T.sub.ref/ T T.sub.ref ).sup.2 ] 〈![CDATA[ ]]〉 A T = A ref x e E o ( Ref A ) a x T - T ref T x T ref + [delta] A x T - T ref T x T ref 2 〈![CDATA[ ]]〉 where A .sub.ref is the net CO.sub.2-assimilation (A) at fixed reference temperature (T .sub.ref), E .sub.o(Ref.sub.A) is the activation energy of A close to T .sub.ref, and [delta] .sub.A describes the change of E .sub.o with increasing incubation temperature (T). Similar to respiration parameters, E .sub.o(Ref.sub.A) and [delta] .sub.A-values were strongly correlated. Symmetry of A/T curves, i.e., constancy of dE .sub.o/dT between 20--45 [degrees]C incubation temperatures, suggests close coordination of component processes underlying A. This symmetry remained at high growth temperature, despite large reductions in biochemical capacity for P .sub.i regeneration relative to carboxylation capacity (i.e., increased abundance of RubisCO activase). Acclimation to higher temperature caused pronounced reductions in physiological capacity of respiration (R .sub.Cap) (type II acclimation, determined via gas exchange measurements). Reductions in R .sub.Cap were not a result of limitations in substrate availability (i.e., pyruvate), but were related to lower abundances of mitochondrial enzymes in well-watered plants (i.e., pyruvate dehydrogenase and cytochrome oxidase). Water shortage led to sucrose accumulation, with modest reductions in mitochondrial enzyme pools. R .sub.Cap remained low when growth temperature was increased. Author Affiliation: (1) Chair of Tree Physiology, Institute of Forest Sciences, Georges-Kohler-Allee 53/54, 79110, Freiburg, Germany (2) Faculty of Agriculture and Environment, The University of Sydney, Sydney, NSW, 2006, Australia (3) College of Sciences, King Saud University, P.O. Box 2455, Riyadh, 11451, Saudi Arabia (4) Department of Plant Systems Biology, University of Hohenheim, 70593, Stuttgart, Germany Article History: Registration Date: 09/11/2016 Received Date: 03/10/2016 Accepted Date: 08/11/2016 Online Date: 09/01/2017 Article note: Communicated by U. Luettge. Electronic supplementary material The online version of this article (doi: 10.1007/s00468-016-1496-0) contains supplementary material, which is available to authorized users.
Arrhenius equation ; Acclimation ; Temperature ; V cmax ; Rubisco activase ; Respiration
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