Carbohydrates Stimulate Ethylene Production in Tobacco Leaf Discs : III. Stimulation of Enzymic Hydrolysis of Indole-3-Acetyl-l-Alanine.

The sucrose-stimulated in vivo hydrolysis of indole-3-acetyl-l-alanine (IAAIa) in tobacco (Nicotiana tabacum L.) leaf discs was confirmed by in vitro analysis of an IAAIa-hydrolyzing enzyme isolated from the same tissue. The enzymic activity could be stimulated by either aging of the tissue or by application of external IAA or sucrose. A combination of the above three treatments yielded maximal activity.