A hydromechanical and biochemical model of stomatal conductance
A hydromechanical and biochemical model of stomatal conductance
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DOI：
10.1046/j.1365-3040.2003.01094.x
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发表时间：
2003-10-01
影响因子：
7.3
通讯作者：
Farquhar, GD
中科院分区：
文献类型：
--
作者：
Buckley, TN;Mott, KA;Farquhar, GD
建立了气孔导度的数学模型。它基于全植物和表皮流体力学，并基于两个假设：(1)保卫细胞膜上的渗透梯度与保卫细胞内的ATP浓度成正比；(2)单位ATP所能维持的渗透梯度与相邻表皮细胞的膨胀压力成正比。在目前的研究中，保卫细胞[ATP]是使用以前发表的模型计算的，该模型基于广泛使用的C-3叶肉光合作用的生化模型。蚕豆的电导模型与大多数其他气孔模型一样被参数化和检验，本模型正确地预测了气孔对蒸腾速率、光照度和胞间CO2变化的响应。然而，与大多数其他模型不同的是，该模型可以预测在电导随湿度、土壤水势或木质部电导下降而下降之前观察到的瞬时气孔开放。该模型还明确地考虑了表皮的机械优势，并正确地预测了气孔对环境氧气分压相对不敏感，这是假设依赖于ATP浓度的结果。
A mathematical model of stomatal conductance is presented. It is based on whole-plant and epidermal hydromechanics, and on two hypotheses: (1) the osmotic gradient across guard cell membranes is proportional to the concentration of ATP in the guard cells; and (2) the osmotic gradient that can be sustained per unit of ATP is proportional to the turgor pressure of adjacent epidermal cells. In the present study, guard cell [ATP] is calculated using a previously published model that is based on a widely used biochemical model of C-3 mesophyll photosynthesis. The conductance model for Vicia faba L. is parameterized and tested As with most other stomatal models, the present model correctly predicts the stomatal responses to variations in transpiration rate, irradiance and intercellular CO2. Unlike most other models, however, this model can predict the transient stomatal opening often observed before conductance declines in response to decreases in humidity, soil water potential, or xylem conductance. The model also explicitly accommodates the mechanical advantage of the epidermis and correctly predicts that stomata are relatively insensitive to the ambient partial pressure of oxygen, as a result of the assumed dependence on ATP concentration.