Chromatin RNA polymerase activity from soybean hypocotyls treated with gibberellic acid and AMO-1618

Chromatin isolated from control, AMO-1618 2′-isopropyl-4′-(trimethylammonium chloride)-5′-methylphenyl piperidine carboxylate] and gibberellic acid (GA) treated soybean hypocotyl tissue incorporates labeled nucleoside triphosphates into acid-insoluble RNA. Gibberellic acid, sprayed on intact soybean hypocotyls, is shown to have enhanced the level of chromatin RNA polymerase activity while chromatin isolated from hypocotyls pretreated with AMO-1618 exhibits a lower polymerase activity relative to the control. Chromatin extracted from the treated or untreated seedlings are all sensitive to the inhibition (in varying degrees) by the presence of actinomycin D, pyrophosphate, or ribonuclease. Thus enhanced (or decreased) RNA-synthesizing capacity of chromatin in response to chemical treatments may be due to enhanced (or decreased) synthesis of RNA polymerase.