CO2 Diffusion Inside Leaf Mesophyll of Ligneous Plants

CO2 diffusion into the leaf to the chloroplast not only depends on stomatal conductance but also on the conductance along the path CO2 follows into the leaf mesophyll from the substomatal cavities to the catalytic sites of Rubisco. Recent methodological advances showed that a significant drop in the CO2 partial pressure may occur along this path [1–5]. Such a drop reveals a low conductance to CO2 diffusion in the mesophyll. A lower conductance in the mesophyll has been shown in leaves of woody plants than in herbaceous plants [4–7].