ATMOSPHERIC OZONE INTERACTS WITH STRESS ETHYLENE FORMATION BY PLANTS TO CAUSE VISIBLE PLANT INJURY

Ozone toxicity was studied in peas, beans, and tobacco (Bel B and Bel W3). These experiments showed that ozone toxicity was related to the rates of ethylene biosynthesis. Sensitivity to ozone was reduced if ethylene biosynthesis was inhibited after treatment with aminoethoxyvinylglycine (AVG). Similarly, plants that were able to reduce or prevent stress ethylene formation were less sensitive after both short- and long-term exposure to ozone. Plants conditioned by longer exposures to ozone have low rates of ethylene formation and this may be why brief ozone exposures may be more phytotoxic than prolonged fumigations.