Origin of Cell wall
Origin of Cell wall /Biogenesis of Cell wall
- The origin of cell wall take place at the end of Telophase of cell Division.
- At the cell division cell plate formation take place in the equator.
- The cell plate is formed by the phragmoplast.
- Phragmoplast include – Fragment of E.R. (Tubules), Fragment of Golgi Bodies (20µm) and Large Vesicles (250µm), these three structures are jointly called phragmoplast.
- For cell plate formation the above said three components arrange themselves in a raw at the equatorial region of cell and divide cytoplasm into two parts.
- After the assembly fragment of E.R. and small vesicles are fused and form a membrane like structure, that joined with plasma membrane of daughter cells.
- After this the larger vesicles that are filled with Ca++ / Mg++ pactet are fused with this layer and formed middle lamella.
- At some point the fusion remain incomplete that result in the formation of plasmodesmata.
- AT both the side of this layer phragmosomes appear which are made of unit membrane and contain granular matrix.
- Their diameter is 250mµ, they also contribute to the material of the middle lamella, then they disappear.
- After this the primary cell wall materials such as cellulose and pectin are deposited.
- At the primary stage it is a thin (1-3µ) elastic and delicate layer . But after the maturation its thickness increase about 5 – 10µ due to the deposition of cell wall forming material.