Temperature‐assisted redistribution of carbohydrates in trees

Abstract

Plants are poikilothermic organisms. Th ey closely follow the temperature of their immediate surroundings, and as a result, their internal body temperature varies considerably. Both seasonal and diurnal temperature variation has shaped plant traits throughout their 430 million year evolutionary history on land. Th us, it is no surprise that plants evolved specifi c traits that use temperature variation to boost physiological performance (Nicotra et al., 2010), just as wood physicochemical properties sustain water transport under tension. Yet our homoeothermic point of view oft en biases notions of how plants could benefi t from energy gradients due to temperature variation. Instead, past research has mainly focused on protection mechanisms across high or low thermal extremes. In reality , all plant physical properties (e.g., viscosity of sap or diff usiv-ity) and chemical activities (e.g., solubility or metabolic rates) are functionally related to temperature (Graham and Patterson, 1982), and, consequently, many physiological processes such as respiration , photosynthesis, and carbohydrate balance respond to temperature. Changes in temperature infl uence all aspects of cellular and physiological functions, even within the range of temperatures regularly experienced by an individual (Larcher, 1995). Moreover, as biochemical pathways are characterized by diff erent thermal kinetics, metabolic processes might be diff erentially aff ected by temperature shift s, ultimately altering cellular physiology. Th e temperature response of biochemical reaction rates is oft en characterized using the Arrhenius equation (Arrhenius, 1889) and temperature coeffi cient 1 1 2 2 10 10