Modes of ethylene action in the release of amylase from barley aleurone layers.

The development of xylanase activity by isolated barley (Hordeum vulgare cv. Himalaya) aleurone layers exposed to gibberellic acid was enhanced by ethylene, whereas the rate of glucanase synthesis was unaffected by ethylene. The elevated xylanase activity expressed in ethylene-treated tissue may be responsible for enhanced release of amylase in response to ethylene.The redistribution of ionic species in response to gibberellic acid and ethylene was explored. The release of calcium was much more sensitive to ethylene than the release of any of the other ions investigated (potassium, magnesium, and phosphate). Ethylene induced a 101% increase in the release of calcium from gibberellic acid-treated aleurone layers. The possible relevance of this observation to the ethylene-enhanced release of amylase is discussed.