Kinin Activity From Plant Extracts

Abstract

A biological assay for substances inducing cell division is described. Blocks of tobacco stem pith were cultured aseptically on 1 ml of basal medium containing mineral salts, sucrose, and vitamins. The addition of auxin to the basal medium caused cell enlargement, but the addition of kinetin alone produced no reaction.Auxin and kinetin together induced cell division, l'esulting in nests of cells readily distinguishable visually from the original cells. Callus produced in this way could be subcultured indefinitely on medium containing bot,h 3-indolylacet,ic acid (IAA)and kinetin.