Temperature response of mesophyll conductance in three C4 species calculated with two methods: 18 O discrimination and in vitro Vpmax.
Temperature response of mesophyll conductance in three C4 species calculated with two methods: 18 O discrimination and in vitro Vpmax.
复制标题
采用 18 O 辨别和体外 Vpmax 两种方法计算了 3 个 C4 物种叶肉电导的温度响应。
作者：
N. Ubierna;A. Gandin;Ryan A. Boyd;A. Cousins
叶肉导度（gm）是限制C3光合速率的重要因子。然而，它在C4光合作用中的作用知之甚少，因为它在历史上一直难以估计。我们使用两种方法来推导C4物种中gm的温度响应。第一个（Δ18 O）将气体交换的测量与18 O区分的模型和测量相结合。第二种方法（在体外Vpmax）推导通用汽车改装模型C4光合作用和13 C歧视与气体交换，动力学常数和体外Vpmax测量。这两种方法对狗尾草和玉米产生了相似的转基因。此外，我们还报道了C4 gm在S. viridis、Z. mays和Miscanthus × Aesteus中的第一个温度响应（10-40°C）。25°C时的gm值为2.90 - 7.85 μmol m-2 s-1 Pa-1。我们的研究表明：这两种描述的方法适合于计算C4物质中的gm; C4中的gm值类似于C3物质报道的高端值; gm随温度增加类似于C3物质报道的，并且响应是物种特异性的。这些结果提高了我们对C4光合作用机理的理解。
Mesophyll conductance (gm ) is an important factor limiting rates of C3 photosynthesis. However, its role in C4 photosynthesis is poorly understood because it has been historically difficult to estimate. We use two methods to derive the temperature responses of gm in C4 species. The first (Δ18 O) combines measurements of gas exchange with models and measurements of 18 O discrimination. The second method (in vitro Vpmax ) derives gm by retrofitting models of C4 photosynthesis and 13 C discrimination with gas exchange, kinetic constants and in vitro Vpmax measurements. The two methods produced similar gm for Setaria viridis and Zea mays. Additionally, we present the first temperature response (10-40°C) of C4 gm in S. viridis, Z. mays and Miscanthus × giganteus. Values for gm at 25°C ranged from 2.90 to 7.85 μmol m-2 s-1 Pa-1 . Our study demonstrated that: the two described methods are suitable to calculate gm in C4 species; gm values in C4 are similar to high-end values reported for C3 species; and gm increases with temperature analogous to reports for C3 species and the response is species specific. These results improve our mechanistic understanding of C4 photosynthesis.
碳酸酐酶催化的热力学。
DOI：
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发表时间：
1981
期刊：
The Journal of biological chemistry
影响因子：
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作者：
Sanyal,G;Maren,TH
通讯作者：
Maren,TH