Is acetaldehyde the causal agent in the retardation of carnation flower senescence by ethanol?

A 3% ethanol holding solution inhibits the conversion of 1-aminocyclopropan e-1-carboxylic acid (ACC) to ethylene, and doubles the vase-life of cut car nation flowers. Although the most effective concentration varies during exp erimentation, high concentrations of ethanol have negative effects. The mos t pronounced of these is the death of the ovary. Ethanol levels are much hi gher in the ovaries of treated flowers, than control flowers. A large amoun t of acetaldehyde was detected in the ovaries of treated flowers. Acetaldeh yde was also detected in all other floral organs tested. Acetaldehyde is pr esent in the head-space surrounding ethanol treated flowers, but not contro l flowers. This indicates that some of the ethanol applied as a post-harves t treatment is broken down to acetaldehyde, within the plant tissue, and re leased into the micro-atmosphere by the flower. If the conversion of ethano l to acetaldehyde is impeded, using an inhibitor of alcohol dehydrogenase, 4-methyl pyrazole, ethanol is no longer effective. Acetaldehyde, (1 and 3 % ), as a holding solution, gave similar results as a 3 % ethanol holding sol ution. It appears that acetaldehyde, produced from ethanol, is the causal a gent for the retardation of carnation flower senescence.