INTERACTION OF METHYL JASMONATE, WOUNDING AND FUNGAL ELICITATION DURING SESQUITERPENE INDUCTION IN HYOSCYAMUS-MUTICUS IN ROOT CULTURES

The ability of methyl jasmonate (MeJa) to induce sesquiterpene product ion in root cultures of Hyoscyamus muticus has been studied. Although MeJa alone could not induce sesquiterpene in unwounded culture, MeJa a dded in the presence of wounding displayed a dose-dependent response, saturating at 50 mu M. The ability to respond to MeJa declined with an increase in time between MeJa contact and wounding; however, responsi veness could be recovered by re-wounding of tissue prior to MeJa conta ct, suggesting that additional signaling related to wounding is requir ed for sesquiterpene pathway induction. The saturation level of sesqui terpene induction with fungal elicitor was four times higher than the saturation level achieved by MeJa, with clear differences in sesquiter pene composition. Fungal elicitation results in a higher level of lubi min and a lower level of solavetivone production; whereas, methyl jasm onate induces predominantly solavetivone and little or no lubimin prod uction. This suggests that fungal elicitation induces enzymes further down the sesquiterpene pathway which are not affected by MeJa. The ind uction of roots in contact with subsaturated levels of elicitor can be enhanced to saturation production levels by the addition of small amo unts of MeJa (5-10 mu moles/l). In these studies, MeJa was consistentl y found to favor the earlier metabolite (solavetivone), while fungal e licitation promoted conversion to subsequent metabolites in the pathwa y (lubimin). The interactive role of MeJa in signal transduction for s econdary metabolic production is discussed.