Eliminating this increased ethylene production may be through an inhibition
of ACC oxidase directly or through an inhibition of its increase following stress.
It is also possible that acetaldehyde acts through a more general inhibition of
metabolism. That acetaldehyde does not have a simple effect on ethylene production
is demonstrated by its ability at low concentrations (in the absence of
exogenous ACC) to enhance ethylene production whereas at higher concentrations
the enhancement is lost.