ENHANCEMENT OF PETUNIA AND DENDROBIUM FLOWER SENESCENCE BY JASMONIC ACID METHYL-ESTER IS VIA THE PROMOTION OF ETHYLENE PRODUCTION

Methyl jasmonate (JA-Me), applied to dendrobium and petunia flowers ei ther as an aqueous solution through the cut stem or stigma, or as a ga s, accelerated senescence. The rate of appearance of wilting symptoms was directly related to the amount of JA-Me applied to the flowers. JA -Me increased ethylene production by the flowers, irrespective of appl ication method, and this effect was also proportional to the dose of t he compound. In both dendrobium and petunia flowers, the JA-Me induced increases in ethylene production and 1-aminocyclopropane-1-carboxylic acid content followed similar patterns. Aminooxyacetic acid, an inhib itor of ACC-synthase, and silver-thiosulfate, an inhibitor of ethylene action, completely inhibited the effects of JA-Me. It is concluded th at JA-Me enhances petunia and dendrobium flower senescence via the pro motion of ACC and ethylene production.