ABSTRACT
Polyamines are metabolically derived from amino acids and play an important role in nucleic acid metabolism and homeostatic regulation of cellular pH. Ethylene is synthesized from methionine via S-adenosyl-1-methionine and 1-aminocyclopropane-1-carboxylic acid (ACC). To confirm further that the ozone damage is caused by ethylene, ACC synthase inhibitor amino-ethoxyvinylglycine (AVG) was used, which dramatically reduced the rate of ethylene evolution. When ethylene production during and after ozone exposure to pea sensitive cultivars Mini and Nugget and tolerant cultivars Charger and Dark Skin Perfection were compared, M. Dijak and D. P. Ormrod found that ethylene production increased in response to ozone, with a greater increase in sensitive cultivars. Mehlhorn and A. R. Wellburn showed that the rate of ozone-stimulated evolution of ethylene was decreased by pretreatment with AVG, a specific inhibitor of ACC synthase. When the seedlings were sprayed with AVG before ozone exposure, the visible leaf injury caused by brief fumigation was almost abolished.
