Three parameters comprehensively describe the temperature response of respiratory oxygen reduction

• Published in: Plant, cell and environment cell and environment, 2008-07, Vol.31 (7), p.954-967
• Main Authors: KRUSE, JÖRG, ADAMS, MARK A
• Format: Article
• Language: English
• Subjects: acclimation; Agricultural and forest climatology and meteorology. Irrigation. Drainage; Agricultural and forest meteorology; Agronomy. Soil science and plant productions; alternative oxidase; Arrhenius model of respiration; Biological and medical sciences; Climatic adaptation. Acclimatization; Fertilizers; Fundamental and applied biological sciences. Psychology; General agronomy. Plant production; Kinetics; Michaelis–Menten kinetics; Nitrogen - metabolism; Oxygen - metabolism; Pinus - metabolism; Pinus - physiology; Plant Leaves - metabolism; Seasons; Temperature; temperature response
• ISSN: 0140-7791; 1365-3040
• DOI: 10.1111/j.1365-3040.2008.01809.x

Using an exponential model that relies on Arrhenius kinetics, we explored Type I, Type II and dynamic (e.g. declining Q₁₀ with increasing temperature) responses of respiration to temperature. Our Arrhenius model provides three parameters: RREF (the base of the exponential model, nmol g⁻¹ s⁻¹), E₀ (the overall activation energy of oxygen reduction that dominates its temperature sensitivity, kJ mol⁻¹) and δ (that describes dynamic responses of E₀ to measurement temperature, 10³ K²). Two parameters, E₀ and δ, are tightly linked. Increases in overall activation energy at a reference temperature were inversely related to changes in δ. At an E₀ of ca. 45 kJ mol⁻¹, δ approached zero, and respiratory temperature response was strictly Arrhenius-like. Physiologically, these observations suggest that as contributions of AOX to combined oxygen reduction increase, E₀(REF) decreases because of different temperature sensitivities for Vmax, and δ increases because of different temperature sensitivities for K₁/₂ of AOX and COX. The balance between COX and AOX activity helps regulate plant metabolism by adjusting the demand for ATP to that for reducing power and carbon skeleton intermediates. Our approach enables determination of respiratory capacity in vivo and opens a path to development of process-based models of plant respiration.