Water enters through the root hair cells, into the root cortex, through the Endodermis into the Xylem. The water is drawn in because of the water potential gradient. The soil has a high water potential and the leaves have a low water potential as the water is evaporating. Creating a water potential gradient high in the roots, low in the leaves.
Inside the Xylem:
There are 3 pathways that the water can take:
1. Apoplast pathway cell wall to cell wall, the non living parts of the cell.
2. Symplast pathway through the cytoplasm, the living parts of the cell.
3. Vacoular pathway through the vacuoles and cytoplasm.
When water reaches the Endodermis travelling via the Apoplast pathway it is blocked by the Casparian ***** - a waxy layer so the water has to follow either the Symplast or Vacoular pathways. Because of…