STIMULATION OF 1-AMINOCYCLOPROPANE-1-CARBOXYLIC ACID-DEPENDENT ETHYLENE PRODUCTION IN DETACHED RICE LEAVES BY METHYL JASMONATE

Effects of methyl jasmonate (JA-Me) on ethylene production in detached rice leaves were investigated. Without 1-aminocyclopropane-1-carboxylic acid (ACC) pretreatment, JA-Me had no effect on ethylene production. However, JA-Me markedly stimulated ethylene production in detached rice leaves pretreated with a saturating concentration of ACC. JA-Me stimulated ACC-dependent ethylene production within 2 h of its application, a result suggesting that JA-Me enhances ACC-dependent ethylene production directly. CoCl2 at 1 mM inhibited ACC-dependent ethylene production stimulated by JA-Me, suggesting that ethylene production from ACC is mediated by the ethylene-forming enzyme. Cycloheximide also inhibited ACC-dependent ethylene production induced by JA-Me, indicating that sustained synthesis of the ethylene-forming enzyme is required. JA-Me stimulated ACC-dependent ethylene production in detached leaves that had been aged for 1, 2 and 3 days. However, aged leaves were less responsive to JA-Me in terms of ACC-dependent ethylene production. Abscisic acid was found to inhibit ACC-dependent ethylene production stimulated by JA-Me.