TY - JOUR

T1 - Uncertainty in measurements of the photorespiratory CO2 compensation point and its impact on models of leaf photosynthesis

AU - Walker, Berkley

AU - Orr, Douglas John

AU - Carmo-Silva, Ana Elizabete

AU - Parry, Martin Afan John

AU - Bernacchi, Carl J.

AU - Ort, Donald R.

PY - 2017/6

Y1 - 2017/6

N2 - Rates of carbon dioxide assimilation through photosynthesis are readily modeled using the Farquhar, von Caemmerer and Berry (FvCB) model based on the biochemistry of the initial Rubisco-catalyzed reaction of net C3 carbon assimilation. As models of CO2 assimilation are used more broadly for simulating photosynthesis among species and across scales, it is increasingly important that their temperature dependencies are accurately parameterized. A vital component of the FvCB model, the photorespiratory CO2 compensation point (*), combines the biochemistry of Rubisco with the stoichiometry of photorespiratory release of CO2. This report details a comparison of the temperature response of * measured using different techniques in three important model and crop species (Nicotiana tabacum, Triticum aestivum and Glycine max). We determined that the different * determination methods produce different temperature responses in the same species that are large enough to impact higher-scale leaf models of CO2 assimilation. These differences are largest in Nicotiana tabacum, and could be the result of temperature-dependent increases in the amount of CO2 lost from photorespiration per Rubisco oxygenation reaction.

AB - Rates of carbon dioxide assimilation through photosynthesis are readily modeled using the Farquhar, von Caemmerer and Berry (FvCB) model based on the biochemistry of the initial Rubisco-catalyzed reaction of net C3 carbon assimilation. As models of CO2 assimilation are used more broadly for simulating photosynthesis among species and across scales, it is increasingly important that their temperature dependencies are accurately parameterized. A vital component of the FvCB model, the photorespiratory CO2 compensation point (*), combines the biochemistry of Rubisco with the stoichiometry of photorespiratory release of CO2. This report details a comparison of the temperature response of * measured using different techniques in three important model and crop species (Nicotiana tabacum, Triticum aestivum and Glycine max). We determined that the different * determination methods produce different temperature responses in the same species that are large enough to impact higher-scale leaf models of CO2 assimilation. These differences are largest in Nicotiana tabacum, and could be the result of temperature-dependent increases in the amount of CO2 lost from photorespiration per Rubisco oxygenation reaction.

KW - Rubisco

KW - Photorespiration

KW - Temperature response

KW - Modeling photosynthesis

U2 - 10.1007/s11120-017-0369-8

DO - 10.1007/s11120-017-0369-8

M3 - Journal article

VL - 132

SP - 245

EP - 255

JO - Photosynthesis Research

JF - Photosynthesis Research

SN - 0166-8595

IS - 3

ER -