In plants, following two pathways are involved in the water movement. They are
(1) Apoplastic pathway
(2) Symplastic pathway
(3) Transmembrane pathway
1. Apoplastic pathway
The apoplastic movement of water in plants occurs exclusively through the cell wall without crossing any
membranes. The cortex receive majority of water through apoplastic way as loosely bound cortical cells do not offer any resistance. But the movement of water in root beyond cortex apoplastic pathway is blocked by casparian strip present in the endodermis.
2. Symplastic pathway
The movement of water from one cell to other cell through the plasmodesmata is called the symplastic
pathway of water movement. This pathway comprises the network of cytoplasm of all cells inter-connected by
plasmodermata.
3. Transmembrane pathway
In plant roots, water movement from soil till the endodermis occurs through apoplastic pathway i.e. only
through cell wall. The casparian strips in the endodermis are made-up of wax -like substance suberin which blocks water and solute movement through the cell wall of the endodermis. As a result water is forced to move through cell membranes and may cross the tonoplast of vacuole. This movement of water through cell membranes is called transmembrane pathway.
