Skip to main content
ARS Home » Research » Publications at this Location » Publication #118662
Title: IMPROVED TEMPERATURE RESPONSE FUNCTIONS FOR MODELS OF RUBISCO-LIMITED PHOTOSYNTHESIS

Author
item BERNACCHI, CARL - PLANT BIOLOGY UOFI URBANA
item SINGSAAS, ERIC - UOFMI BIOLOGICAL STATION
item PIMENTEL, CARLOS - UNIV RIO DEJANERIO BRAZIL
item PORTIS JR, ARCHIE
item LONG, STEPHEN - PLANT BIOLOGY UOFI URBANA

Submitted to: Photosynthetic CO2 Assimilating Enzymes Rubisco and Pepc Conference
Publication Type: Abstract Only
Publication Acceptance Date: 12/3/2000
Publication Date: N/A
Citation: N/A

Interpretive Summary:

Technical Abstract: Predicting environmental responses of leaf photosynthesis is central to many models of changes in future global carbon cycle and terrestrial biosphere. The steady-state biochemical modes of C3 photosynthesis of Farquhar et al. provides a basis for these larger scale predictions; but weakness in the application of the model as currently parameterized is the inability to predict accurately carbon assimilation at the range of temperatures over which significant photosynthesis occurs in the natural environment. In this study, transgenic tobacco containing only 10 percent normal levels of Rubisco were used to measure Rubisco-limited photosynthesis over a large range of CO2 concentrations. From the responses of the rate of CO2 assimilation at a wide range of temperatures, and CO2 and O2 concentrations, the temperature functions of Rubisco kinetic properties were estimated in vivo. These differed substantially from previously published functions. These new functions were then used to predict photosynthesis in lemon and found to faithfully mimic the observed pattern of temperature response. There was also a close correspondence with published C3 photosynthesis temperature responses. The results represent an improvement ability to model leaf photosynthesis over a wide range of temperatures (10-40 degree C) necessary for predicting carbon uptake by terrestrial C3 systems.