9 Major Difference Between Apoplast And Symplast Pathways

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There are two types of transport pathway for the conduction of the water from one region to another. The path followed by the water can be Symplast or Apoplast pathway. The Symplast is the pathway in which the water molecules move through the plasmodesmata region in the cells. The Symplast is the living region present between two cells which connect one cell with the other. The Apoplast pathway is the path in which the water is moving between the intercellular spaces. The Apoplast includes the non-living spaces between cells and the cell membrane.

Both the pathways are involved in the movement of water across the root. Water flows via Apoplast in the cortex. It enters the Symplast pathway in the endodermis where walls are impervious to flow of water due to the presence of casparian strips.

What Is Apoplast?

Apoplast is the space outside the plasma membrane that allows free movement of material. This pathway plays a crucial role and allows diffusion of a solvent across the tissue or organ. It is broken up by the casparian strip in roots, by air spaces between plant cells and by the plant cuticle.

In the Apoplast pathway, water is transported from the root hair to xylem through the cell wall of intervening cells without crossing any membrane or cytoplasm. The pathway provides the least resistance to the movement of water. However, it is interrupted by the presence of impermeable lignosuberin casparian strips in the walls of endodermal cells.

What You Need To Know About Apoplast

  1. Apoplast refers to the nonprotoplasmic components of a plant including the cell wall and the intracellular spaces.
  2. Apoplast consists of nonprotoplasmic parts such as cell wall and intracellular space.
  3. Apoplast is composed of non-living parts of a plant.
  4. In Apoplast, the water movement occurs by passive diffusion.
  5. In Apoplast, the water movement is rapid.
  6. The metabolic rate of the cells in the root cortex does not affect the water movement.
  7. It shows less resistant to the water movement.
  8. With the secondary growth of the root, most of the water moves by the Apoplast route.
  9. It is not aided by streaming movement of cytoplasm.

What Is Symplast?

Symplast is the protoplasts present in plants, which are interconnected by the plasmodesmata. It is the inner part plasma membrane, which plays a vital role in transporting or free movement of water and other low-molecular-weight solutes such as sugars, amino acids and other ions in between cells.

In Symplast pathway, water passes from cell to cell through their protoplasm. It does not enter cell vacuoles. Symplastic movement is aided by Cytoplasmic streaming of individual cells. It is, however, slower than apolastic movements.

What You Need To Know About Symplast

  1. Symplast refers to the continuous arrangement of protoplasts of a plant, which are interconnected by plasmodesmata.
  2. Symplast consists of protoplast.
  3. Symplast is composed of living parts of a plant.
  4. In Symplast, the water movement occurs by osmosis.
  5. In Symplast, the water movement is slower.
  6. The metabolic rate of the cells in the root cortex highly affects the water movement.
  7. It shows some little resistance to the water movement.
  8. Beyond the cortex, water moves through the Symplast.
  9. It is aided by streaming movements of cytoplasm.

Also Read: Difference Between Simple And Facilitated Diffusion

DifferenceBetween Apoplast And Symplast Pathways In Tabular Form

BASIS OF COMPARISON APOPLAST SYMPLAST
Description Apoplast refers to the nonprotoplasmic components of a plant including the cell wall and the intracellular spaces.   Symplast refers to the continuous arrangement of protoplasts of a plant, which are interconnected by plasmodesmata.  
Contents Apoplast consists of nonprotoplasmic parts such as cell wall and intracellular space.   Symplast consists of protoplast.  
Composition Apoplast is composed of non-living parts of a plant.   Symplast is composed of living parts of a plant.  
Water Movement In Apoplast, the water movement occurs by passive diffusion.   In Symplast, the water movement occurs by osmosis.  
Speed Of Water Movement In Apoplast, the water movement is rapid.   In Symplast, the water movement is slower.  
Metabolic Rate The metabolic rate of the cells in the root cortex does not affect the water movement.   The metabolic rate of the cells in the root cortex highly affects the water movement.  
Resistance To Water Movement It shows less resistant to the water movement.   It shows some little resistance to the water movement.    
Water Channel With the secondary growth of the root, most of the water moves by the Apoplast route.   Beyond the cortex, water moves through the Symplast.  
Cytoplasmic Streaming It is not aided by streaming movement of cytoplasm.   It is aided by streaming movements of cytoplasm.  

Similarities Between Apoplast And Symplast

  • Apoplast and Symplast are two ways in which the water moves from root hair cells to the xylem.
  • Both the Apoplast and Symplast occur in the root cortex.
  • Both the Apoplast and Symplast carry water and nutrients towards the xylem.

Also Read: Difference Between Active And Passive Transport