Although MJ and PDJ induced highly comparable effects on ethylene production, fruit quality, and jasmonic acid accumulation, their transcriptional effects only partly coincided. Most probably this difference is due to PDJ’s synthetic nature. A methyl esterase has been reported which hydrolyses MJ to jasmonic acid (Stuhfelder et al., 2004); the latter may be further metabolized to other JAlike compounds (Staswick and Tiryaki, 2004). Little is known about PDJ metabolism in plants; in grape berries, it is converted into compounds other than MJ or jasmonic acid (Koshiyama et al., 2006). In tomato, a microarray analysis showed that, while some genes respond in the same manner to all members of the JA family, others do so in a differential manner (Uppalapati et al., 2005). Thus, early on, the different transcriptional responses to MJ versus PDJ may be direct and depend upon differential gene behaviour. At ripening, the response could be indirect, due to biochemical transformation of the applied JAs, and the complex transcriptional framework resulting from the overlap of defence responses and ripening.