Ozone: An abiotic elicitor of plant defence reactions.

The air pollutant ozone has recently been found to resemble fungal elicitors — it can induce plant signal molecules such as ethylene and salicylic acid, as well as certain genes and biosynthetic pathways associated with pathogen and oxidative defence. The action of ambient ozone on the plant defence system may predispose the plant to enhanced attack by pathogens, but may also lead to induced resistance. The results mean that ozone can be regarded as a new experimental tool for analyzing stress responses