Jasmonate levels and defense-related phenotypes of transgenic tomato plants silenced for OPR3 expression by RNAi. The figure summarizes the main findings of study  addressing the effect of JA/JA-Ile deficiency of OPR3-silenced plants on constitutive and induced defenses against the specialist herbivore M. sexta (green, red and yellow arrows indicating up- or down-regulation and no change in OPR3-RNAi as compared to control plants, respectively). OPR3-RNAi plants contain less JA/JA-Ile as compared to the wild type, and there is no wound-induced increase in JA or JA-Ile (left panel). As a result of JA/JA-Ile deficiency, trichome density and terpene content are reduced, while cis-3-hexenal concentration is increased in OPR3-RNAi as compared to wild-type plants (right panel, top). OPR3-RNAi plants are preferred by gravid M. sexta females for oviposition, and by the larvae for feeding (right panels, center). The development of M. sexta larvae is indistinguishable on OPR3-RNAi and wild-type plants (right panel, bottom). Resistance against larval feeding is thus maintained in the absence of JA/JA-Ile and was attributed to the local induction of defense gene expression by OPDA.