Semiquantitative determination of the compensation point for CO2 in C3 and C4 plants as an experimental practice in the teaching of Plant Ecophysiology

The compensation point for CO2 (ΓCO2) is the minimum limit of atmospheric CO2 necessary for positive photosynthetic assimilation. Below this limit, respiratory processes predominate over photosynthetic processes, net photosynthesis has negative values ​​and growth stops, with negative consequences on yield and productivity. Differences in ΓCO2 have been used to select genotypes with a higher CO2 uptake capacity and better productivity. The objective of this work is to contribute to the practical knowledge, by students of a Plant Ecophysiology subject, of how the value of ΓCO2 can be calculated and its interest in evaluating the efficiency of CO2 uptake by plants with C3 photosynthetic metabolism or C4. Summary: The compensation point for CO2 (ΓCO2) is the minimum limit of atmospheric CO2 necessary for positive photosynthetic assimilation. Below this limit, respiratory processes predominate over photosynthetic ones, net photosynthesis has negative values ​​and growth stops, with negative consequences on yield and productivity. Differences in ΓCO2 have been used to select genotypes with a higher CO2 uptake capacity and better productivity. The objective of this work is to contribute to the practical knowledge, by students of a Plant Ecophysiology course, of how the value of ΓCO2 can be calculated and its interest in evaluating the efficiency of CO2 uptake by plants with C3 or C4 photosynthetic metabolism. respiratory processes predominate over photosynthetic ones, net photosynthesis has negative values ​​and growth stops, with negative consequences on yield and productivity. Differences in ΓCO2 have been used to select genotypes with a higher CO2 uptake capacity and better productivity. The objective of this work is to contribute to the practical knowledge, by students of a Plant Ecophysiology course, of how the value of ΓCO2 can be calculated and its interest in evaluating the efficiency of CO2 uptake by plants with C3 or C4 photosynthetic metabolism. respiratory processes predominate over photosynthetic ones, net photosynthesis has negative values ​​and growth stops, with negative consequences on yield and productivity. Differences in ΓCO2 have been used to select genotypes with a higher CO2 uptake capacity and better productivity. The objective of this work is to contribute to the practical knowledge, by students of a Plant Ecophysiology course, of how the value of ΓCO2 can be calculated and its interest in evaluating the efficiency of CO2 uptake by plants with C3 or C4 photosynthetic metabolism.