Is peroxidase involved in ethylene biosynthesis?

Abstract
Wheat (Triticum aestivum L. cv. Jubilar) coleoptile segments convert 1‐aminocyclopropane‐1‐carboxylic acid (ACC) to ethylene. This process is totally inhibited by nitrogen atmosphere and severely inhibited by free radical scavengers (sodium benzoate, ferulic acid), inhibitors of reactive ‐SH groups (p‐chlormercuribenzoate, iodoacetate), CoCl2 and EDTA. Indole‐3‐acetic acid, aminoethoxyvinyl glycine, cycloheximide, actinomycin D, pyridoxal phosphate and NADH have no effect on ACC conversion to ethylene. Some in vivo characteristics of this conversion suggest that it could be catalyzed by peroxidase. However, isoperoxidase B1 isolated from wheat seedlings was not able to catalyze in vitro conversion of ACC to ethylene under a wide range of reaction conditions. Therefore, it is concluded that peroxidase is not directly involved in ethylene biosynthesis.