Apoplastic reaches the endodermis

Casperian strip (waterproof band) prevents water going any further through the cell walls

Water forced into living protoplast 

Joins water from the symplasic pathway in the cytoplasm

Active transport of salts is the likely way

Need carrier proteins in cell membrane so water must enter cytoplams of endodermal cells 

ATP from inside the cell used to actively transport the salts but water must be inside the cell

Explains why casperian strip is there

Active transport of mineral ions into the xylem lowers its water potntial so water moves in

This creates root pressure to help it move up the plant

Minimal contribution to movement of water compared to transpiration pull

Root pressure makes a significant difference

Due to active transport of salts

Pressures increase and decrease with an increase or decrease in temperature

Low concentration of O₂ or glucose results in low root pressure

metabolic inhibitors prevent most ATP being released and root pressure to cease

Water loss from leaves creates transpiration pull

Pulls water up stem

Starts at stomata