Involvement of jasmonate- and salicylate-related signaling pathways for the production of specific herbivore-induced volatiles in plants

We compared volatiles from lima bean leaves (Phaseolus lunatus) infested by either beet armyworm (Spodoptera exigua), common armyworm [Mythimna (Pseud aletia) separata], or two-spotted spider mite (Tetranychus urticae), We als o analyzed volatiles from the leaves treated with jasmonic acid (JA) and/or methyl salicylate (MeSA), The volatiles induced by aqueous JA treatment we re qualitatively and quantitatively similar to those induced by S, exigua o r M. separata damage. Furthermore, both S, exigua and aqueous JA treatment induced the expression of the same basic PR genes. In contrast, gaseous MeS A treatment, and aqueous JA treatment followed by gaseous MeSA treatment, i nduced volatiles that was qualitatively and quantitatively more similar to the T. urticae-induced volatiles than those induced by aqueous JA treatment . In addition, T. urticae damage resulted in the expression of the acidic a nd basic PR genes that were induced by gaseous MeSA treatment and by aqueou s JA treatment, respectively. Based on these data, we suggest that in lima bean leaves, the JA-related signaling pathway is involved in the production of caterpillar-induced volatiles, while both the SA-related signaling path way and the JA-related signaling pathway are involved in the production of T, urticae-induced volatiles.