What is the relationship between Photosynthetic rate (Pn) and intracellular CO2 (Ci)?
How the Ci may affect the Pn, and whats their relationship, either positive, negative, or both are possible (under which condition)? Thanks
There is a positive relationship between Photosynthesis rate and intercellular CO2
@ Muhammad, yes, the relationship is positive. With increase in the carbon dioxide concentration the rate of photosynthesis generally increases until limited by another factor. Elevated carbon dioxide is generally causes increased photosynthesis in plants, which leads to greater production of carbohydrates and biomass.
The relation is complicated by the diffusion gradients and stomatal aperture. You need to look up the relevant papers
The relationship may be positive. However, the increase in intracellular CO2 may to limit the diffusion of atmospheric CO2 and so decreased stomatal conductance or photosynthesis. Furthermore the increased intracellular CO2 may to indicate a low activity of photosynthetic enzymes such as RuBisCo. On the hand, the relationships between Ci and Pn is positive, when the intracellular concentrations CO2 are lower with respect to atmospheric or environmental CO2 concentrations and so increases the rate of photosynthesis . I suggest to read review papers