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 immunogold labeling of ultrathin sections of pollen tubes of Nicotiana tabacum L. to unravel the ultrastructural localization of myosin associated with the generative cells, Clusters of immunogold particles were consistently found in association with the area of the outer surface of the vegetative cell plasma membrane present around the generative cell. Compared to the generative cell cytoplasm, the nucleoplasm showed higher numbers of gold particles. This is the first direct evidence demonstrating the presence of myosin in the nuclei of the generative cell of flowering plants. The possible implications of these findings are discussed in relation to movement of the generative cell in the pollen tube cytoplasm.