Figure 1.

Effects of pretreatment with exogenous MeJA on ozone-induced leaf damage and defense gene induction. a, Individual leaves were sprayed with different concentrations of JA in 0.1% (w/v) Triton X-100 until runoff occurred. The fourth fully expanded leaf from three trees per concentration was harvested 24 h after treatment, and pooled for RNA isolation and subsequent northern-blot analysis using WIN 3.7 as a probe. b, Plants were treated either 3 or 24 h prior to ozone fumigation with a solution of 200 μm MeJA in 0.1% (w/v) Triton X-100, and 24 h after the start of the ozone treatment, plants were assessed for the percent leaf injury. The data for each test condition represent the mean ± se of two to six individual plants. Data shown are representative of one of three independently performed experiments.