Kinetin-induced Meiotic-Prophase Acceleration and Stasis in Tradescantia Anthers cultured on Media Deficient in Sugar

Abstract

THE ability of kinetin to accelerate mitotic division has been demonstrated for Paramecium¹, and an apparent effect of accelerating prophase has been inferred from onion root-tip work². That the acceleration may be a direct consequence of a hormonal acceleration of discrete phases of cellular metabolism has been suggested^3,4. The former workers found that synthesis of deoxyribonucleic acid (DNA) could be induced in tobacco pith tissue by kinetin; the latter found that it increased the activity of deoxyribonuclease and ribonuclease from bean hypocotyls. It is known that indole-3-acetic acid is also required for stimulation of division by kinetin and it has been shown that it is also required for the effect on nucleic acid metabolism^1–4. In contrast with the stimulation of nuclear and cellular division, most workers have found that in higher concentrations kinetin causes abnormalities of division and eventually mitotic activity ceases.