Root uptake of soil water

In most flowering plants, plasma membrane transport proteins control the plant’s uptake of water and mineral ions from soil.

1 Most soil water moves from epidermis to vascular cylinder by diffusing through root cell walls.

2 The Casparian strip prevents soil water from diffusing around endodermal cells. To enter the vascular cylinder, water and dissolved mineral ions must enter cytoplasm by passing through the plasma membrane of a root cell.

3 Mineral ions actively transported into root hairs diffuse through plasmodesmata to the vascular cylinder.