Fig. 4.

Average (+SE) emission rates of the individual lipoxygenase pathway volatiles (LOX volatiles) hexanal (A) and pentanal (B) and average (+SE) elicitation rate of hexanal (C) and pentanal (D) in mature leaves of 10- to 12-week-old N. tabacum ‘Wisconsin’ at different recovery times (0.5, 3, 10, 24, and 48 h for emission rate and 0.5, 10, and 48 h for elicitation rate) after ozone exposure at 0, 400, 600, 800, and 1000 ppb for 30 min in a custom-made cylindrical double-walled glass chamber at 25 °C. The elicitation rate of emissions is defined as the rate of change of emission (positive values indicate an increase of the rate and negative values a decrease of the rate). Data are averages of three independent replicates. Individual effects of ozone, recovery time (Time), and their interactions on emission rates were tested by GLM with maximum likelihood model fitting. Wald’s chi-square (χ²) test statistics and statistical significance are indicated as *P<0.05, **P<0.01, ***P<0.001. (This figure is available in color at JXB online.)