Figure 6. Levels of salicylic acid (SA) and jasmonic acid (JA) in infected Valley Forge (VF) and susceptible (S) American elm saplings.

(a,b) The levels of SA and JA were assessed in stem tissues (~2 cm²) around the inoculation zone at 0, 24, 48, 96, 122 and 144 hpi with the O. novo-ulmi (10⁷ spores/ml). The results are the mean ± SE of three biological replicates. Values marked with an asterisk (*) are significantly higher (P < 0.05) than the control sample (0 hpi) and the corresponding time point in the other genotype.