Figure 3

Variation in volatile sesquiterpene emission and terpene synthase transcript levels between different sides of a leaf damaged by herbivory on one side. (A) The cartoon illustrates the different leaf parts collected for volatile and transcript analysis. One S. littoralis larva was enclosed for seven hours on leaf part I of the second fully expanded leaf of maize variety Delprim. (B) Emission of (E)-α-bergamotene and (E)-β-farnesene (TPS10 products) and (E)-β-caryophyllene (TPS23 product) from different leaf parts after herbivory restricted to one section on one side. Volatiles were collected from tissue powder using SPME and analyzed by GC-MS. Data are means of four replications ± SE. Different letters with the same numbered subscripts (e.g. a¹ and b¹) indicate statistically significant (p<0.05) differences between the volatile measurement among the five distinct sections of one leaf for each set of sesquiterpene products. Control tissue (Ctr) was harvested from an undamaged leaf. (C) Transcript accumulation of tps10 and tps23 in different leaf parts after herbivory restricted to one section on one side. RNA was prepared from an aliquot of the tissue powder used for volatile analysis (see above). The samples were blotted and probes specific for tps10 and tps23 were used for hybridization. The 28S RNA is shown as a loading control on an ethidium bromide stained argarose gel.