Márquez Diego A, Stuart-Williams Hilary, Farquhar Graham D
Research School of Biology, The Australian National University, Canberra, Australian Capital Territory, Australia.
Nat Plants. 2021 Mar;7(3):317-326. doi: 10.1038/s41477-021-00861-w. Epub 2021 Mar 1.
The widely used theory for gas exchange proposed by von Caemmerer and Farquhar (vCF) integrates molar fluxes, mole fraction gradients and ternary effects but does not account for cuticular fluxes, for separation of the leaf surface conditions or for ternary effects within the boundary layer. The magnitude of cuticular conductance to water (g) is a key factor for determining plant survival in drought but is difficult to measure and often neglected in routine gas exchange studies. The vCF ternary effect is applied to the total flux without the recognition of different pathways that are affected by it. These simplifications lead to errors in estimations of stomatal conductance, intercellular carbon dioxide concentration (C) and other gas exchange parameters. The theory presented here is a more precise physical approach to the electrical resistance analogy for gas exchange, resulting in a more accurate calculation of gas exchange parameters. Additionally, we extend our theory, using physiological concepts, to create a model that allows us to calculate cuticular conductance to water.
冯·凯默勒和法夸尔（vCF）提出的广泛应用于气体交换的理论整合了摩尔通量、摩尔分数梯度和三元效应，但未考虑角质层通量、叶表面条件的分离或边界层内的三元效应。角质层对水的导度（g）大小是决定植物在干旱中存活的关键因素，但难以测量，且在常规气体交换研究中常被忽视。vCF三元效应应用于总通量时，未认识到受其影响的不同途径。这些简化导致气孔导度、细胞间二氧化碳浓度（C）和其他气体交换参数估算出现误差。这里提出的理论是一种更精确的物理方法，用于气体交换的电阻类比，从而更准确地计算气体交换参数。此外，我们运用生理学概念扩展理论，创建了一个模型，使我们能够计算角质层对水的导度。
