An Early Response to Gibberellic Acid Not Requiring Protein Synthesis

Abstract

Cell-free extracts from gibberellic acid-treated barley (Hordeum vulgare L. cv. Himalaya) aleurone layers show phosphorylcholine glyceride transferase activity greater than that from control layers. The increase in activity is not prevented by a mixture of amino acid analogs nor by cordycepin under conditions in which it is demonstrated that the analogs and the cordycepin are entering the cells in effective concentrations. We conclude therefore that the GA(3)-dependent increase in phosphorylcholine glyceride transferase activity (which occurs within the first 4 hours of GA(3) treatment) does not require RNA synthesis or protein synthesis.