Characterization of photosynthetic acclimation in Phoenix dactylifera by a modified Arrhenius equation originally developed for leaf respiration

摘要: Instantaneous temperature responses of leaf respiration and photosynthesis can be described by the same equation, to help understand acclimation primary metabolism altered growth water supply. We used a three-parameter, modified Arrhenius originally developed for respiration, characterize A/T curves Date Palm elevated deprivation: $$A_{\text{T}} = A_{\text{ref}} \times e^{{\left[ {\frac{{E_{\text{o}} (\text{Ref}_{\text{A}} )}}{\Re } \left( {\frac{{T - T_{\text{ref}} }}{{T }}} \right) + \delta_{\text{A}} \right)^{2} \right]}}$$ where A ref is net CO2-assimilation (A) at fixed reference (T ref), E o(RefA) activation energy A close T ref, δ describes change o with increasing incubation (T). Similar parameters, A-values were strongly correlated. Symmetry curves, i.e., constancy dE o/dT between 20–45 °C temperatures, suggests coordination component processes underlying A. This symmetry remained high temperature, despite large reductions in biochemical capacity P i regeneration relative carboxylation (i.e., increased abundance RubisCO activase). Acclimation higher caused pronounced physiological (R Cap) (type II acclimation, determined via gas exchange measurements). Reductions R Cap not result limitations substrate availability pyruvate), but related lower abundances mitochondrial enzymes well-watered plants pyruvate dehydrogenase cytochrome oxidase). Water shortage led sucrose accumulation, modest enzyme pools. low when was increased.