Cytokinins

Cytokinins have specific effects on cytokinesis (cell division). They were discovered as kinetin, a modified form of adenine (a purine), obtained from autoclaved herring sperm DNA. Kinetin does not occur naturally in plants. The search for natural substances with cytokinin-like activity led to the isolation of zeatin from corn kernels and coconut milk. Since the discovery of zeatin, several naturally occurring cytokinins, and some synthetic compounds with cell-division-promoting activity, have been identified.

Natural cytokinins are synthesised in regions where rapid cell division occurs — for example, in root apices, developing shoot buds and young fruits.

The main effects of cytokinins include: …