Page 195 - PG 101-Course notes مذكرة النظري 24-25 with spec

Medicinal plants (PG 101) Level 1 Clinical Pharmacy-PharmD

Water in the roots move by two pathways. They can be classified as:

1) Apoplast pathway 2) Symplast pathway

1) Apoplast pathway:

• In this pathway the movement of water occurs exclusively through cell wall

without the involvement of any membranes. Majority of the amount of water

goes through the apoplast pathway. The cortex of the root does not oppose
such movement of the water.

2) Symplast pathway:

• Here the movement of water molecules is from cell to cell through the

plasmodesmata. The plasmodesmata forms a network of cytoplasm of all cells.

The Casparian strip separates the cortex and the endodermis. It is composed of a

wax like substance called suberin, which blocks water and solute molecules

through the cell wall of the endodermis. Now the water is forced to go through

the cell membranes of different cells leading to a transmembrane pathway.

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