Lateral transport in roots.

  1. Root hairs absorb water and minerals, which move along the walls comprising the apoplast.

  2. Minerals and water that cross the plasma membranes of root hairs enter the symplast.

  3. Along the apoplast some water and minerals are transported into the cytosols of cells and then move via the symplast.

  4. The Casparian strip, a belt of waxy material, allows only minerals in the symplast to pass into the vascular cylinder through the plasma membrane of endodermal cells.

  5. Cells in the vascular cylinder transport water and minerals throughout the plant.