Cellular Distribution of Polysome Populations of Castor Bean Endosperm

The distribution of polysomes in the cells of the endosperm of very young (48 hours of germination) seedlings of castor bean (Ricinus communis var. Hale) has been examined. Seedlings exposed to 100 micromolar gibberellin A(3) for periods up to 24 hours showed increased numbers of polysomes associated with endomembranes. Cytosol-derived polysomes were generally of a shorter mean length than membrane-derived polysomes. Gibberellin did not lead significantly to increased numbers of cytosol-derived polysomes, nor did it lead to enhancement of any particular size class of polysomes.