Abstract
Two flue-cured tobacco [Nicotiana tabacum] cultivars, ''North Carolina 88'' and ''Coker 86'', were fumigated with 0-0.30 ppm O3 for 6 h. Both cultivars were highly sensitive to O3. Plants fumigated with concentrations of O3 > 0.15 ppm displayed typical weather fleck symptoms. Fumigation for 6 h with 0.25 or 0.30 ppm O3 resulted in a significant increase in the lipid concentration but a decrease in the concentration of free sterols and triglyceride fatty acids in all leaf tissues. These changes were not correlated with injury ratings. Triglyceride fatty acids and other cellular components were probably being utilized for membrane repair.