Improved temperature response functions for models of Rubisco-limited photosynthesis
Improved temperature response functions for models of Rubisco-limited photosynthesis
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DOI：
10.1111/j.1365-3040.2001.00668.x
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发表时间：
2001-02-01
影响因子：
7.3
通讯作者：
Long, SP
中科院分区：
文献类型：
--
作者：
Bernacchi, CJ;Singsaas, EL;Long, SP
预测叶片光合作用的环境响应是未来全球碳循环和陆地生物圈变化模型的核心。Farquhar等人（Planta 149，78-90，1980）的C-3光合作用的稳态生物化学模型为这些更大规模的预测提供了基础;但是当前参数化的模型的应用中的弱点是不能准确地预测在自然环境中发生显著光合作用的温度范围内的碳同化。该模型中使用的温度函数基于在有限温度范围内进行的体外测量，并需要对体内条件进行若干假设。由于光合速率往往是Rubisco有限的（核酮糖，1-5二磷酸羧化酶/加氧酶）在自然的稳态条件下，在不同的温度下预测Rubisco动力学特性的功能的不准确性可能会导致显着的错误。在这项研究中，转基因烟草只含有10%的正常水平的Rubisco被用来测量Rubisco限制光合作用在一个大范围的CO2浓度。从CO2同化速率在很宽的温度范围内的响应，和CO2和O-2浓度，Rubisco动力学性质的温度函数估计在体内。这些功能与以前发布的功能有很大不同。这些新的功能，然后被用来预测柠檬的光合作用，并发现忠实地模仿观察到的温度响应模式。与已发表的C-3光合温度响应也有密切的对应关系。这些结果代表了在预测陆地C-3系统碳吸收所需的广泛温度范围（10-40摄氏度）内模拟叶片光合作用的能力得到了提高。
Predicting the environmental responses of leaf photosynthesis is central to many models of changes in the future global carbon cycle and terrestrial biosphere. The steady-state biochemical model of C-3 photosynthesis of Farquhar et al. (Planta 149, 78-90, 1980) provides a basis for these larger scale predictions; but a weakness in the application of the model as currently parameterized is the inability to accurately predict carbon assimilation at the range of temperatures over which significant photosynthesis occurs in the natural environment. The temperature functions used in this model have been based on in vitro measurements made over a limited temperature range and require several assumptions of in vivo conditions. Since photosynthetic rates are often Rubisco-limited (ribulose, 1-5 bisphosphate carboxylase/oxygenase) under natural steady-state conditions, inaccuracies in the functions predicting Rubisco kinetic properties at different temperatures may cause significant error. In this study, transgenic tobacco containing only 10% 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 O-2 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 C-3 photosynthesis temperature responses. The results represent an improved ability to model leaf photosynthesis over a wide range of temperatures (10-40 degreesC) necessary for predicting carbon uptake by terrestrial C-3 systems.