Reduction in Extractable Deoxyribonucleic Acid Polymerase Activity in Pisum sativum Seedlings by Ethylene

An extract from the apical portion of etiolated seedlings of Pisum sativum L. was used as a test system to examine the action of ethylene on DNA polymerase activity. The extract catalyzed the polymerization of labeled deoxyribonucleoside triphosphates into a trichloroacetic acid-insoluble product. The system required Mg(2+), nicked DNA, and all four deoxyribonucleoside triphosphates for maximum activity. Extracts from plants previously treated with ethylene showed less activity to synthesize DNA than extracts from nontreated plants. Loss of extractable DNA polymerase activity may be due to accumulation of a non-competitive inhibitor in the ethylene-treated plants. Treating the extract with ethylene did not affect the polymerase activity. Inhibition of cell division by ethylene observed in this and other tissues may be the result of accumulation of an inhibitor of DNA polymerase.