The subcellular organization of guard and subsidiary mother cells in sugarcane leaves was examined by electron microscopy. Guard and subsidiary mother cells assume a characteristic shape before mitosis and contain variable numbers of mitochondria, proplastids, dictyosomes, and cisternae of rough endoplasmic reticulum. In guard mother cells, the nucleus occupies a central position, whereas in subsidiary mother cells, the nucleus is located toward one end of the cell, near the guard mother cell. Microtubules are found in both guard and subsidiary mother cells and are either closely grouped to form defined preprophase bands or randomly dispersed between the nucleus and the preprophase bands. Many of the dispersed microtubules occur in close association with the nucleus in both guard and subsidiary mother cells. Possible functions for these preprophase microtubules are discussed in relation to their organization in the preprophase band, their orientation, and their distribution within guard and subsidiary mother cells.
Influence of extract from shoots of Taxus baccata var. elegantissima on ultrastructure and tubulin cytoskeleton of meristematic cells of Allium cepa L. roots
