Environmental regulation of the oxygen effect on apparent photosynthesis in wheat

A closed gas exchange system was used to survey the apparent rates of photosynthesis by young wheat shoots in a wide range of O 2 concentrations (O 2 ), CO 2 concentrations (CO 2 ), temperatures (T), and radiant flux densities. The results are expressed graphically and by equations. The carbon dioxide compensation point (Γ H ) conformed to the equation Γ H = O 2 e (0.0428T − 12.1) . The relationship between the apparent rates of photosynthesis in the presence (P H ) and absence (P L ) of inhibitory concentrations of oxygen was described by the equation P H = P L k log e (CO 2 /Γ H ) where k was independent of the prevailing environmental conditions and [Formula: see text].