All the protoplasts in plants and their interconnecting cytoplasmic channels—the plasmodesmata. This effectively forms a continuous system of cytoplasm bounded by the plasma membranes of the cells. The movement of water through the symplast is known as the symplastic pathway. It is one of the routes by which water travels across the root cortex from the root hairs and is the only means by which water crosses the endodermis. Compare apoplast.