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The effect of temperature on C 4 ‐type leaf photosynthesis parameters
Author(s) -
MASSAD RAIASILVIA,
TUZET ANDRÉE,
BETHENOD OLIVIER
Publication year - 2007
Publication title -
plant, cell and environment
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.646
H-Index - 200
eISSN - 1365-3040
pISSN - 0140-7791
DOI - 10.1111/j.1365-3040.2007.01691.x
Subject(s) - photosynthesis , rubisco , phosphoenolpyruvate carboxylase , stomatal conductance , c4 photosynthesis , chemistry , botany , biology
C 4 ‐type photosynthesis is known to vary with growth and measurement temperatures. In an attempt to quantify its variability with measurement temperature, the photosynthetic parameters – the maximum catalytic rate of the enzyme ribulose 1·5‐bisphosphate carboxylase/oxygenase (Rubisco) ( V cmax ), the maximum catalytic rate of the enzyme phosphoenolpyruvate carboxylase (PEPC) ( V pmax ) and the maximum electron transport rate ( J max ) – were examined. Maize plants were grown in climatic‐controlled phytotrons, and the curves of net photosynthesis ( A n ) versus intercellular air space CO 2 concentrations ( C i ), and A n versus photosynthetic photon flux density (PPFD) were determined over a temperature range of 15–40 °C. Values of V cmax , V pmax and J max were computed by inversion of the von Caemmerer & Furbank photosynthesis model. Values of V pmax and J max obtained at 25 °C conform to values found in the literature. Parameters for an Arrhenius equation that best fits the calculated values of V cmax , V pmax and J max are then proposed. These parameters should be further tested with C 4 plants for validation. Other model key parameters such as the mesophyll cell conductance to CO 2 ( g i ), the bundle sheath cells conductance to CO 2 ( g bs ) and Michaelis–Menten constants for CO 2 and O 2 ( K c , K p and K o ) also vary with temperature and should be better parameterized.