“…Enzymic conversion of methionine analogs to ethylene catalvzed by peroxidase has been elucidated recently (5,6,11,12,15,17); a-keto-y-methylthiobutyric acid and methional, but not methionine, are the active substrates. A chemical mechanism accounting for suich enzymic formation of ethylene has been described (15)(16)(17)(18). On tlle basis of this information, Yalng (16) has proposed the following scheme for the biosynthesis of ethylene in plants: methionine -> a-keto-y-methylthiobutyric acid -+ methional -) ethylene.…”