The
phragmosome is a sheet of cytoplasm forming in highly vacuolated
plant cells in preparation for
mitosis. In contrast to animal cells, plant cells often contain large central
vacuoles occupying up to 90% of the total cell volume and pushing the
nucleus against the
cell wall. In order for mitosis to occur, the nucleus has to move into the center of the cell. This happens during G1<ref>Plant Biology,Andrew Lack and David Evans</ref> phase of the
cell cycle.