plasmodesma

Plasmodesmata (singular: plasmodesma) are microscopic channels which traverse the cell walls of plant tissue and some algal cells, enabling transport and communication between them.

Unlike animal cells, every plant cell is surrounded by a polysaccharide cell wall. Neighbouring plant cells are therefore separated by a pair of cell walls and the intervening lamella, forming an extracellular domain known as the apoplast. Although cell walls are permeable to small soluble proteins and other solutes, plasmodesmata enable direct, regulated, symplastic intercellular transport of substances between cells.

Three layer Structure: plasmodesmatal plasma membrane, cytoplasmic sleeve and desmotubule.