MEASUREMENT OF THE RATE OF CO2 SOLUBILIZATION IN LEAF TISSUE WITH THEHELP OF A ZIRCONIUM-OXIDE OXYGEN ANALYZER

A novel method for the measurement of the rate of CO2 exchange caused by solubilization and bicarbonate formation in leaves is presented. Th e method is based on the measurement of changes in O-2 concentration, caused by the uptake or evolution of CO2 from the gas flow as a result of solubilization in or desolubilization from leaf tissue, by means o f a zirconium-oxide O-2 analyser. The advantages of the new method are a fast response and a lack of interference by the CO2 contained in th e leaf chamber and leaf intercellular spaces, The method can be used f or the investigation of the kinetics of CO2 transport from leaf interc ellular spaces to chloroplasts and the role of carbonic anhydrase in t his transport and the investigation of mechanistic and ecological aspe cts of buffering, proton translocation and other processes controlling pH in chloroplasts of intact leaves.