Ethylene Action Inhibitors Suppressed Clomeprop Metabolite [2-(2, 4-Dichloro-m-Tolyloxy) Propionic Acid]-Induced Electrolyte Leakage from Radish Roots

Abstract

Involvement of ethylene was investigated in the physiological mechanism of clomeprop [2-(2, 4-dichloro-m-tolyloxy) propionanilide]- or its hydrolytic metabolite DMPA [2-(2, 4-dichloro-m-tolyloxy) propionic acid]-induced electrolyte leakage from radish roots. The treatment of DMPA to radish roots caused increase of electrolyte leakage from the roots, suppression of the root growth and stimulation of ethylene production. Although ethylene action inhibitors, 2, 5-norbornadiene (NBD) and cis-propenylphosphonic acid (PPOH), did not suppress ethylene evolution from the DMPA-treated radish roots for the first 24hrs, these compounds suppressed the electrolyte leakage and to some extent restored the growth of lateral roots. Evan's blue dye tests revealed that death of the root cells occurred 12hr after the DMPA treatment. This indicated that the increase in electrolyte leakage preceded the death of the root cells. These results suggest that the ethylene induced by DMPA is attributable to the leakage of electrolyte from the radish roots.