Comparison of the Disruption of Mitosis and Cell Plate Formation in Oat Roots by DCPA, Colchicine and Propham

Abstract

Holmsen, J. D. and Hess, F. D. 1985. Comparison of the disruption of mitosis and cell plate formation in oat roots by DCPA, colchicine and propham.—J. exp. Bot. 36: 1504–1513. Concentrations of DCPA, propham and colchicine were selected to cause from 0% to greater than 60% inhibition of oat (Avena sativa L. ‘Victory’) root growth after 24 h exposure. Root growth progressively declined as concentrations were raised from 1·0 to 5·6 mmol m⁻³ DCPA, 1·0–5·0 mmol m⁻³ propham, and 50–500 mmol m⁻³ colchicine. In addition to inhibiting root growth each mitotic disrupter caused the root tips to swell to an extent dependent upon concentration. All three compounds effectively disrupted mitosis at concentrations that caused less than maximal root growth inhibition. Mitotic disruption was manifest as a reduction in the number of normal mitotic figures and an increase in the number of condensed prophase, multipolar and anaphase bridge division figures. The frequency of each type of division figure was different for each of the three compounds. DCPA disrupted mitosis more effectively when compared with propham and colchicine at concentrations which caused the same amount of root growth inhibition. Each mitotic disrupter also induced the formation of aberrant cell walls. DCPA was the most effective at disrupting cell plate formation, whereas colchicine was least effective. These data suggest that the mechanism of action of DCPA is distinct from the mechanism of colchicine or propham