Stress ethylene evolution: A measure of ozone effects on plants

Abstract

To determine if ethylene evolution by plants was correlated with ozone stress, a range of plant species and cultivars was exposed to varying ozone concentrations. Following exposure, the plants were encapsulated in plastic bags and incubated for up to 22 h. The stress-induced ethylene that accumulated in the bag was monitored and correlated with the effects of ozone on plants. The rate of stress-induced ethylene production (slope parameter B) as a function of ozone concentration was used as a measure of plant sensitivity. Applying this ranking scale, ponderosa pine, eucalyptus and soybean were the most sensitive species; holly, squash and marigold were least sensitive. There was a good correlation between ozone-induced stress ethylene production and foliar injury. However, the coefficient of variability associated with the ethylene determination was substantially less than with the visual injury estimate. The production of stress-induced ethylene generally lasted for less than 48 h following exposure. The measurement of stress ethylene appeared to be a fast, reliable, sensitive and reproducible technique to measure ozone stress on plants.