The role of ethanol or acetaldehyde in the biosynthesis of ethylene in carnation (Dianthus caryophyllus L.) cv. Yellow Candy

Carnation (Dianthus caryophyllus L.) cv. Yellow Candy flowers were treated with ethanol solution (4%) in the absence or presence of 1 or 10 mM L-methionine, or ethanol or acetaldehyde solution (0.05%), in the absence or presence of 1 mM aminocyclopropane carboxylic acid (ACC). Spermidine in petals was measured over time in flowers treated with 4% ethanol or distilled water. Ethanol treatment significantly increased vase life by 10 days; methionine had no significant effect. The vase life of ACC-treated flowers was reduced by 4 days, the ethylene climacteric peak advanced by 5 days and ethylene production was increased in comparison with flowers not treated with ACC. In the absence of ACC, ethanol solution significantly increased vase life of carnation cv. Yellow Candy by 5 days and inhibited ethylene production, whereas in the presence of ACC, ethanol neither increased vase life nor inhibited ethylene production. Acetaldehyde also failed to increase vase life of carnation cv. Yellow Candy either in the absence or presence of ACC. There was no difference between spermidine content of ethanolor distilled water-treated flowers. It was concluded that 4% ethanol failed to inhibit conversion of methionine to S-adenosyl methionine (SAM) because ethanol failed to inhibit production of spermidine. Furthermore, ethanol or acetaldehyde also failed to inhibit conversion of ACC to ethylene. © 2001 Elsevier Science B.V. All rights reserved.