Ethylene production from propanal.

Tracer studies using a model system consisting of Cu(2+) and ascorbate indicate that carbons 2 and 3 of propanal are converted to ethylene, and carbon 1 is converted to formic acid and CO(2). A mechanism accounting for this reaction is described. In apple tissue, methionine but not propanal is readily incorporated into ethylene. It is therefore concluded that propanal is not a precursor of ethylene in this fruit.