celleplade

Cell plate (celleplade in Danish) is a plant-specific structure that forms during cytokinesis to separate the cytoplasm of two daughter cells. It originates from membrane vesicles that bud from the Golgi apparatus and accumulate at the center of the cell where a phragmoplast guides them to fusion. These vesicles carry components needed for the cell wall, including pectin, cellulose, and hemicellulose, and they may carry enzymes such as callose synthases. Initially, the vesicles fuse to form a small, disk-shaped or plate-like membrane layer that expands outward as more vesicles join. A temporary matrix rich in callose is deposited at the leading edges during this process and is later replaced as the cell plate matures. The expanding cell plate eventually develops into a separating cell wall, forming the primary cell walls of the daughter cells and the middle lamella that connects them.

The phragmoplast, a plant-specific assembly of microtubules and actin filaments, directs vesicle transport and fusion to the center of the cell. Once the cell plate has fused with the existing cell membranes at the periphery, the cell plate thins and tightens into the mature cell wall between the two daughter cells.

In contrast to animal cytokinesis, which relies on a contractile ring to form a cleavage furrow, plant cytokinesis proceeds by vesicle-driven assembly of the cell plate. Cell plate formation is essential for plant tissue development and is a key step in establishing the final cell walls that define plant anatomy.