LASER PHOTOACOUSTIC-SPECTROSCOPY OF BIOSYSTEMS GAS-EXCHANGE WITH THE ATMOSPHERE

A response of plants to stress action is characterized by an activatio n of the respiration process. The CO2 evolution by some plants exposed to elevated concentration of pollutants and pressure decrease is stud ied using a photoacoustic spectrometer with a CO2 laser. The measureme nts show a considerable CO2 evolution by all kinds of the test plants. The quantity of CO2 emitted by pea seedlings at 8 kPa, for example, e xceeds the control one by about 20 times (24 h after the exposure star t). The exposure of pea seedlings to C2H4 and O-3 at various concentra tions also increases CO2 evolution: the 48-h exposure of test plants t o C2H4 (at 0.01 ppm) increases CO2 evolution by approximately 100% wit h respect to the control plants.