Effect of Ethanol on ACC Synthase Activity and Gene Expression in Ripening Banana

Postharvest application of 35-90% ethanol is reported to remove astringency and improve sweetness of banana. In order to determine the specific pattern and localization of gene expression, banana fruits were treated with 60% ethanol and control and then the total RNA extracted from the banana was hybridized with the RNA probe of ACC synthase gene. The highest ACC synthase activity was observed at 6 days after the ethanol treatment, while the accumulation of MA-ACS 1 mRNA (encoding banana ACC synthase during ripening) was observed in 9 days after the same treatment. In this experiment, the date of highest ethylene production coincided with the date of highest ACC synthase activity. The expression of ACC synthase gene is considered to occur firstly in pulp and then it occur in the peel on the basis of the signal intensity by Northern blot analysis.