Figure 7.

TPS10 plants and the wild type accumulate similar levels of defense metabolites after multiple elicitations when grown alone or in competition with wild-type or TPS10 neighbors (mean ± sem, n = 6). Labels in A apply to A, C, E, and G, whereas labels in B apply to B, D, F, and H. Leaves were harvested from the same plants before (+1) and 48 h after the first of three elicitations with W+OS over 18 h across 2 d (+2); differences in metabolite accumulation caused by either direct induction or priming of the induced response could thus be amplified and detected. Levels of several defense metabolites elicited by herbivory, including TPIs (A and B), caffeoylputrescine (C and D), and two malonylated HGL-DTGs nicotianoside VI (E and F) and VII (G and H), showed few or no differences among lines or in response to different neighbors. The Holm-Bonferroni method was used to correct for two to three tests of each data set (effect of line within individuals or competing pairs, effect of neighbor within competing pairs, effect of competition, and post hoc pairwise tests); each ANOVA and its accompanying post hoc tests were counted as single tests for P value correction. Different letters indicate significant differences (P < 0.05) after Holm-Bonferroni correction of Tukey’s HSD mean-separation tests of genotype for caffeoylputrescine at 2 d or neighbor identity (wild-type neighbor or 10-3 neighbor) and the interaction between line and neighbor identity (10-3 versus the wild type and 10-3 versus 10-4) for nicotianoside VI at 0 d. nd, Not detected; ns, not significant, v., versus; WT, wild type.