Apoplast Pathway and Water Movement

The movement of water in a plant can take place through two pathways- symplast and apoplast. In the apoplast pathway, water moves exclusively through the cell walls and intercellular spaces. Let us understand this process in detail.

Apoplast Pathway

The apoplast pathway is the movement of water through the spaces outside the plasma membrane of plant cells. It includes the cell walls, intercellular spaces, and extracellular matrix. The apoplast pathway is the primary route for water movement in the roots and stems of plants.

Process of Water Movement in Apoplast Pathway

The following are the steps involved in the movement of water in the apoplast pathway:

1. Entry of water into the root hairs:
Water enters the root hairs through osmosis. The root hairs are surrounded by a film of water, which dissolves mineral ions, making them easier to absorb.

2. Movement through the apoplast pathway:
Water moves through the cell walls and intercellular spaces of the root cortex via the apoplast pathway.

3. Crossing the endodermis:
The endodermis is a layer of cells that surrounds the vascular tissues of the root. It is also known as the casparian strip. It is a waterproof strip of suberin that blocks the apoplast pathway, forcing the water to enter the symplast pathway.

4. Movement through the symplast pathway:
Water moves through the cytoplasm of the cells via the symplast pathway. It crosses the endodermis and enters the vascular tissues.

5. Transport to the stem and leaves:
Water is transported to the stem and leaves via the xylem.

Apoplast Pathway and Water Movement in NEET

In NEET, questions related to the apoplast pathway and water movement are asked to test the knowledge of the candidates about plant physiology. The candidates are expected to understand the process of water movement through the apoplast pathway and the significance of the apoplast pathway in the transport of water in plants.

Conclusion

In conclusion, water moves exclusively through the cell walls and intercellular spaces in the apoplast pathway. It is an important pathway for the transport of water in plants and is significant in the uptake and transport of mineral nutrients. Candidates appearing for NEET must understand the apoplast pathway and water movement in detail to answer questions related to plant physiology.