Aminoethoxyvinylglycine, cobalt and ascorbic acid all reduce ozone toxicity in mung beans by inhibition of ethylene biosynthesis

Abstract

Evidence is presented in support of the hypothesis that stress ethylene formation determines ozone toxicity in plants. In studies with mung beans ( Vigna radiata ) ozone toxicity was reduced not only when plants had been pretreated with aminoethoxyvinylglycine (AVG) but also after pretreatment of plants with CoCl 2 and ascorbic acid. While AVG prevents the enzymatic conversion of S‐adenosylmethionine (SAM) to I‐aminocyclopropane‐I‐carboxylic acid (ACC), cobalt and free radical scavengers such as ascorbic acid inhibit the subsequent conversion of ACC to ethylene. Stomatal opening was not affected by pretreatment of plants with inhibitors of ethylene biosynthesis.