Final answer:
Plant cells exchange materials through the plasma membrane using plasmodesmata, which are channels that pass between adjacent plant cells' cell walls.
Step-by-step explanation:
In general, plant cells exchange materials through the plasma membrane using plasmodesmata. These are numerous channels that pass between the cell walls of adjacent plant cells, connecting their cytoplasm. Plasmodesmata allow transport of water, nutrients, and other molecules from cell to cell, enabling communication and nutrient exchange throughout the plant.