ETHYLENE EVOLUTION OF GERMINATING PEAS EXPOSED TO OZONE

The ethylene evolution of germinating peas Pisum savitum L. exposed to elevated ozone levels is studied using a CO2 laser-driven photoacoust ic detection system. For ozone fumigation experiments a specific flow system is developed resulting in adjustable, controlled ozone concentr ations between 270 and 10 ppbv in air. Ozone fumigation enhances ethyl ene production, even before the onset of visible germination, and inhi bits growth as compared to non-fumigated pea seedlings. The combinatio n of ozone fumigation and application of the ACC-synthase inhibitor AV G still yields increased ethylene levels indicating an alternative pat hway for enhanced ethylene production.