The effect of 2,4,5-TP and ethylene on the abscission of bean explants

Abstract

This study was undertaken in an attempt to show that a favourable gradient of 2-(2,4,5-trichlorophenoxy) propionic acid (2,4,5-TP) across abscission zones prevents abscission in bean explants by rendering them insensitive to ethylene. The effect of applied ethylene and an ethylene-free atmosphere on the abscission of explants was studied. It was found that 2,4,5-TP greatly enhanced 14 C-ethylene evolution from 14 C-methionine by explants and petiole sections and that applied ethylene could not induce abscission in explants treated with 2,4,5-TP. Untreated explants eventually abscised in an ethylene-free atmosphere.