Plants require require water, light and CO2 to photosynthesise.
The general formula for the process is:
CO2 + 2 H2O + photons → (CH2O)n + H2O + O2
(carbon dioxide + water + light energy → carbohydrate + oxygen + water)
If you remove, or significantly reduce any one of those items from the formula, the reaction doesn't happen.
Atmospheric levels of CO2 are generally between 360 and 390ppm.
Once levels drop below about 200ppm, plant growth is significantly stunted.
Depending on the type of plant, amount and wavelength of light, temperature and moisture levels, at 160ppm plants will not grow at all- i.e. die.
Industrial greenhouses (and serious gardeners) keep levels of CO2 at elevated levels, up to 1000ppm to accelerate plant growth. Even in vented greenhouses levels can drop below 200ppm during the day.
In this instance, the only research needed was O-Level Biology.