Airborne methyl jasmonate stimulates the biosynthesis of furanocoumarins in the leaves of celery plants (Apium graveolens)

When leaves ofApium graveolens are exposed to vapours of methyl jasmonate (MeJa) or fed through the petiole with aqueous solutions of jasmonic acid (Ja), the levels of natural furanocoumarins, in particular xanthotoxin and bergapten, are greatly increased. The induction becomes manifest after application of 20 nmol of either Meja or Ja. Levels of xanthotoxin and bergapten begin to increase approximately 24 h after application of the inducer. Maximum concentration of the two furanocoumarins (40–70 fold increase) is reached after 4–6 days. This pronounced effect of volatile MeJa on the physiological status of the celery leaf may be considered as representative of a build-up of chemical defenses, in an undamaged plant, after receipt of airborne signals from damaged or undamaged, but fragrant plants.