Figure 1.

Ectopic expression of TPS10 and the point mutant TPS10M results in greater headspace abundance of (E)-β-farnesene and/or (E)-α-bergamotene versus the wild type. A, Simplified mechanism of TPS10 and TPS10M (modified from Köllner et al., 2009). TPS10 (B and C) and TPS10M (D and E) lines consistently emit more (E)-β-farnesene (B and D) and/or (E)-α-bergamotene (C and E) than wild-type plants from leaves treated with several herbivory-related elicitors (mean ± sem, n = 4). Note the different scales: data in B and C and data in D and E are from two separate experiments conducted within the same week; all plants were in the same growth stage (elongated). The headspace of the second fully expanded leaf (+2) on plants was collected without treatment (Con) or for 24 to 32 h after treatment with W+W (W+OS control), W+OS, Lan (Lan+MJ control), or Lan containing 150 µg of MJ (Lan+MJ). In the Con and Lan treatments, there was very low but detectable (E)-α-bergamotene emission from the wild type (<0.1 ng). Nontarget volatiles from these plants did not differ among transgenic lines and the wild type (PCAs in Supplemental Figs. S2 and S3). nd, Not detected; ns, not significant; WT, wild type. *, P < 0.05; **, P < 0.01 versus the wild type within each treatment after Holm-Bonferroni corrections for multiple testing if required (the wild type was tested against lines 10-3 and 10-4) after Wilcoxon rank sum tests or Welch’s t tests (marginally significant corrected P values [<0.1] are written above bars).