The plant cell wall is a dynamic compartment that changes throughout the life of the cell. The middle lamella forms the interface between the primary walls of neighboring cells. The plant cell wall is a highly organized composite of many different polysaccharides, proteins, and aromatic substances. Not all specialized functions of cell walls are structural. Some cells walls contain molecules that affect patterns of development and mark a cell s position within the plant.
Walls contain signaling molecules that participate in cell cell and wall nucleus communication.
The primary walls of cells are capable of expansion. The middle lamella is formed during cell division and grows coordinately during cell expansion. Contact between certain cells is maintained by the middle lamella, and the cell corners are often filled with pectin-rich polysaccharides. The production of complex, chemically diverse molecules within cell walls is developmentally regulated. The autofluorescence of lignin is shown in red.