The Golgi apparatus and an early stage in cell plate formation

Abstract

Glutaraldehyde-fixed, osmium postfixed root apex cells in successive stages of cytokinesis show the involvement of small vesicular bodies in cell plate formation. These bodies apparently are produced by the Golgi apparatus; beginning by metaphase, they invade the spindle, cluster in the equatorial regions of the cell, and seem to set up some condition essential for the fusion of large Golgi vesicles in the same region. The plate is formed by this fusion, during which the small vesicles are incorporated into it. Plate formation proceeds centrifugally, with spindle fibers and clusters of the small vesicular bodies marking the edges, around which vesicle-producing Golgi apparatus are grouped. Puromycin affects either the production of the small vesicular bodies or their movement away from the Golgi cisternae. Colchicine precludes fusion of the larger Golgi vesicles, apparently by preventing clustering of the small ones, perhaps indirectly through effects on the spindle.