Assembly and disassembly of the peripheral architecture of the plant cell nucleus during mitosis

The architecture of the nuclei of higher plants includes a structure similar to the nuclear lamina of vertebrates. Changes in this structure were monitored during mitosis in carrot (Daucus carota L.) and celery (Apium graveolens L.) cells by immunofluorescence microscopy using an antibody that recognized the nuclear-matrix protein NMCP1. This protein has been shown to be localized exclusively at the periphery of the nucleus (K. Masuda et al. 1997, Exp Cell Res 232: 173-187). Immunofluorescence was recognized throughout cells in mitotic metaphase, although it was distributed predominantly in the mitotic spindle zone. At late anaphase or telophase, the immunofluorescence was localized around each set of daughter chromosomes. Immunofluorescence in newly formed daughter nuclei was restricted to the periphery of nuclei. This behavior was very similar to that of the nuclear lamina of vertebrates, suggesting that the structure located between the nuclear envelope and the chromosomes in plants disassembles and assembles in parallel with the disintegration and re-formation of the nuclear envelope.