IMMUNOELECTRON MICROSCOPY OF MYOSIN ASSOCIATED WITH THE GENERATIVE CELLS IN POLLEN TUBES OF NICOTIANA-TABACUM-L

In this study, polyclonal anti-myosin antibodies were used for immunog old labeling of ultrathin sections of pollen tubes of Nicotiana tabacu m L. to unravel the ultrastructural localization of myosin associated with the generative cells, Clusters of immunogold particles were consi stently found in association with the area of the outer surface of the vegetative cell plasma membrane present around the generative cell. C ompared to the generative cell cytoplasm, the nucleoplasm showed highe r numbers of gold particles. This is the first direct evidence demonst rating the presence of myosin in the nuclei of the generative cell of flowering plants. The possible implications of these findings are disc ussed in relation to movement of the generative cell in the pollen tub e cytoplasm.