Fig. 4.

Average (+SE) emission rates of individual lipoxygenase pathway volatiles (LOX) hexanal (A), and pentanal (B) and average (+SE) elicitation rate of hexanal (C) and pentanal (D) in mature leaves of 10-12 weeks old N. tabacum ‘Wisconsin’ at different recovery times (0.5, 3, 10, 24, and 48 hours for emission rate and 0.5, 10, 48 hours 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 chi-square (χ²) test statistics and statistical significance are indicated as: * - P < 0.05, ** - P < 0.01, *** - P < 0.001.