Alcohol Dehydrogenase Activity in Relation to Flooding Tolerance in Roots

The ability of a number of plants to grow under conditions of experimental flooding has been examined. There was an increase in ethanol production under anaerobic conditions in those species whose growth was reduced by flooding. The period of flooding induced a marked increase in alcohol dehydrogenase activity of the roots of these plants. Plants not adversely affected by flooding showed no increase in ethanol production and no induction of alcohol dehydrogenase activity. It is suggested that species in which such activation occurs are excluded from wet areas because of the accumulation of toxic quantities of ethanol.