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Could someone explain the apoplast and simplest pathway?

Could someone explain the apoplast and simplast pathway in its simplest terms.

(edited 10 years ago)

Apoplastic Pathway:
As water's drawn into the endodermal cells, more water is pulled along behind it due to the COHESIVE properties of water molecules. This creates a tension that draws water along the cell walls of the cells of the root cortex.

Symplastic Pathway: (takes place across cytoplasm of the cells)
1. Water enters root hair cells by osmosis, increasing their water potential (WP)
2. WP in root hair cells are now greater than WP in 1st cortex cell. So, water moves by osmosis down the water potential gradient (WPG) from the root hair cell to the 1st cortex cell.
3. 1st cell now has higher WP than neighbouring cell so again, water moves into 2nd cell by osmosis along the WPG. (and this continues)
4. The loss of water from the previous cells lowers their WP causing more water to enter it by osmosis from root hair cell.
5. A WPG is set up in this way.

Hope that's okay for you!