Dear Prof. Raj Kumar Kapooria ,

CO2 is only one of the gasses involved in the exchange occurring in the sub-stomatal chamber (or cavity) and gas exchange and diffusion its only one of its functions.

The mere idea of increasing CO2 inhalation implies a reduction of all the exchanges outward.

Most importantly stomata allow evotranspiration producing water potential gradients, that is also why their closure is regulated by guard cells turgor generated by hydrostatic pressure.

One can see how complex the issues is by noticing that different stomatal regulation is matched by a different metabolism (CAM, C3 and C4).

Without efficient evotranspiration the plant would not be able to absorb water from the soil, which implies no uptake of the nutrients in solution, loss of turgor, embolism by cavitation and no way to decrease the temperature quickly.

Furthermore, xylem, tracheids and vessels require water to maintain structural metastability.

Increasing pressure would decrease the evotranspiration rate, reducing the water potential.

Temperature gradient cannot change much without causing an abiotic stress to the plant and even in that range it can cause significant changes in it, including fruits, which possess functional stomata as well.

Higher temperature increases the water evaporation from the soil, which either produces humidity or drought. Higher humidity and temperature would promote the growth of pathogens, as it as been shown by several studies on climate change effect on crops.

Increasing the concentration of CO2 works to a certain extent, but the plants require O2 for respiration as well and controlled environment such as greenhouses still requires pollinators and human intervention. Thus, it is extremely difficult and expensive to manage.

Maybe in the future it will be possible to have a completely automatized greenhouse where robots replace humans and pollinators and the air composition, pressure and humidity and light can be fine-tuned to obtain a desired phenotype predicted on models and real-time phenotyping.

You can only increase or decrease the rate of uptake by changing the CO2 concentration and other factors like light, temperature or any other factor which influence the degree of aperture or influencing the rate of depletion of CO2.

Dear Raj Kumar Kapooria

I think this article can be useful to you.

https://www.publish.csiro.au/FP/PP9860281

depends on the concentration gradient of CO2 inside and outside of the cells and other factors like light intensity, humidity, temperature