Selective Inhibition of Cell Cycle Stages in the Allium Root Meristem by Colchicine and Growth Regulators

Abstract

The treatment of root tips of Allium carinatum, Allium cepa, and Allium flavum with colchicine, abscisic acid, kinetin, and indole‐3‐acetic acid, applied in appropriate concentrations, combinations, and durations, makes possible the selective blockade of the cell cycle in G1, G2, any mitotic stage, and between karyokinesis and cytokinesis. Moreover, treatment with abscisic acid followed by a recovery period stimulates polyploid nuclei in mature tissues to divide. Colchicine, kinetin, and indole‐3‐acetic acid applied together cause end‐to‐end association of metaphase chromosomes. These results together with earlier findings suggest that any step of the cell cycle is independently controlled both by specific balance of the growth regulators and by specific synthesis of the nucleic acids.

Signalling of abscisic acid to regulate plant growth

“…Approximately 30 years ago, it was observed that ABA inhibits DNA replication in root tips and embryos of Fraxinus excelsior (van Overbeek et al 1967;Villiers 1968). Histochemical studies of root tissues supported the notion of an ABA-mediated inhibition of cell elongation and of an arrest in mitotic cell activity, presumably in the G1phase (Nagl 1972;de la Torre et al 1972).…”

A Comparison Of The Effect Of NaCl On The Cell Doubling Time Of The Root Apical Meristem In Triticum aestivum (cvs. Lyallpur 73, Pak 81 and Lu-26-S)

“…As colchicine is a highly cytotoxic drug and may itself perturb the passage of cell through the cell cycle. The drug has been shown to adversely affect the number of cells in prophase (Webster and Davidson, 1969), the passage of the cells through interphase (Nagl, 1972) and the duration of the cell cycle itself (Webster and Davidson, 1969;Macleod, 1971). Despite these drawbacks the use of rate of colchicine-induced metaphase accumulation to estimate cell doubling time is still a valuable tool for comparative studies of contrasting cultivars to varying concentration of NaCI.…”

Localization of Endogenous Growth Substances in Freesia hybrida ‘Moya’ Corms Before and After a Heat Treatment1

“…The significance of the IAA increase and shifts in IAA balance in the lateral buds and in the remaining corm tissue from the beginning to the end of the 13 week 30°C heat treatment is still uncertain. The balance and conversion rate between free and conjugated IAA forms, if known, would indeed provide a better understanding of the relationship between IAA and freesia corm dormancy and sprouting (15).…”