Pericycle
Pericycle is a layer of cells that surrounds the stele in the root or stem of plants. It is made up of sclerenchymatous or parenchymatous cells that lie just inside the endodermal layer. The pericycle has a unique ring-like or cylindrical structure that can be easily identified from other cells. It distinguishes the stele from other cells of the root or stem.
In dicot roots, the pericycle protects the vascular bundles and gives rise to lateral roots. Lateral roots are not found in monocots. It also contributes to the secondary growth of the plants by developing into cork cambium.
Endodermis
Endodermis is the innermost layer of the cortex. It acts as a boundary between the cortex and stele. It is made up of a single layer of barrel-like cells that are saturated with a suberised layer called casparian strips. The presence of casparian strips blocks the passage of water and solutes apoplastically (it is a space outside the plasma membrane that allows free diffusion of water).
The major function of the endodermal layer is to allow the movement of water and dissolved solutes only through the endodermal cells. Thus, the movement of water in or out of the xylem can be regulated by the endodermis. There are also starch granules embedded in the endodermal cells called amyloplasts that serve as the site of food storage.
Pericycle vs Endodermis
|
Pericycle |
Endodermis |
|
Description |
|
|
A layer of cells encircling the vascular bundles is referred to as a pericycle. |
The innermost layer of cortex is referred to as endodermis. |
|
Layers |
|
|
Multilayered |
It is a single layer. |
|
Composition |
|
|
It is made of sclerenchymatous or parenchymatous cells. |
It is made up of mainly parenchymatous cells. |
|
Location |
|
|
It lies between the endodermis and vascular bundles. |
It lies between the pericycle and cortex. |
|
Specialised Structure |
|
|
No such presence. |
It is embedded with a layer of suberin substances called casparian strips. |
|
Function |
|
|
It strengthens the roots, aids in the development of lateral roots, and also contributes to secondary growth. |
It allows the movement of water and dissolved solutes that come from the xylem via the endodermal cell layers. It also has starch granules that act as the site for storage of food. |
Explore BYJU’S Biology to learn more.
Also Read:
- Why Is the Endodermis Essential in the Root?
- What Is The Difference Between Epidermis And Endodermis?
- Anatomy of Dicotyledonous and Monocotyledonous Plants
- Is Pericycle A Ground Tissue?
Frequently Asked Questions
What is the difference between the pericycle and cambium?
Pericycle is a layer of cells that surrounds the vascular bundles, whereas cambium is the layer of cells present between the xylem and phloem.
Is endodermis present in all roots and stems?
Endodermis is not found in the stems of woody plants.
What is the cortex made up of?
Cortex is made up of thin walled parenchymatous cells.
Comments