Changes Accompanying the Addition of 2, 4-D to Excised Jerusalem Artichoke Tuber Tissue

Abstract

Cultured in the absence of 2, 4-D, explants excised from Jerusalem artichoke tubers show no measurable increase in cell-number, fresh weight, or DNA content and only a small increase in RNA and protein. Consequent on the addition of 2, 4-D all these parameters increase rapidly. A detailed study of the events immediately following the addition of 2, 4-D after 5 days' culture in a mineral salts and sucrose medium shows the induction of DNA replication prior to synchronous cell division in about 35 per cent of the cells. It is a feature of this experiment that large-scale RNA accumulation occurs only in cells preparing for this division while RNA accumulated in most of the remaining cells before the addition of 2, 4-D is lost. The possible role of 2, 4-D in the induction of cell division is discussed.