XVI International Botanical Congess
Cell division in Sphagnum leaves results in two types of cells, large spirally-thickened hyaline cells bordered by narrow chlorophyllous cells. The leaf is unistratose and primordial leaves have cells in progressive stages of differentiation, providing an ideal system for the study of the cytoskeleton. Immunofluorescence staining of microtubules in intact leaf cells reveals important information about the cytoskeleton in cell wall development and cell-cell interactions. Microtubules form distinct spiral arrays prior to deposition of hyaline cell wall thickenings and they aggregate near walls of sister cells. Microtubule arrays form distinct cortical bands in files of young cells and appear to play an important role in defining cell clusters which have divided unequally prior to differentation. These results provide information for understanding the tensegral network between cells within the Sphagnum leaf.