Figure 5.

Ethylene synthesis in ozone-exposed tomatoes deficient in ethylene biosynthesis or perception. ACC concentrations and ethylene evolution were measured from ozone-exposed (filled symbols) and clean air control (blank) tomato wild-type cv VF-36 and transgenic LE-ACS2 antisense plants (A) and from ozone-exposed cv Ailsa Craig and transgenic LE-ACO1 antisense plants (B). C, ACC synthase activity and ethylene evolution were measured from ozone-exposed cv Pearson and ethylene-insensitive Nr mutant. D, Concentrations of conjugated ACC were measured from ozone-exposed VF36, LE-ACS2 antisense (in cv VF36), cv Ailsa Craig, and LE-ACO1 antisense (in cv Ailsa Craig) tomatoes during and after the 5-h ozone exposure. Plants were treated for 5 h with 200 nL L⁻¹ ozone (indicated with black line above the graphs) and were postcultivated in pollutant-free air. Means ± se (n = 3).