Plant Cell Wall Formation: 5 Facts You Should Know

This article has focused on the details of plant cell wall formation along with the associated facts important for the process of cell wall formation. 

Cell wall can be described as the rigid and specialised structure in plants which is made up of extracellular matrix and surrounds the cell membrane. It has three specific layers, the primary cell wall, followed by the middle lamella and the innermost secondary cell wall. 

What is plant cell wall formation?

The cell wall of plants is identified as a dynamic and specialised network which is formed by the heterogeneous mixture of cellulose, pectins and hemicellulose along with extent proteins and phenolic compounds. The biosynthesis of the cell wall begins during the division of cells during the phase of cytokinesis

The formation of the cell plate occurs during the cell wall generation in plants. Then, the primary cell wall is formed with the deposition of cellulose, pectin and hemicellulose. The formation is processed largely on the carbohydrate-carbohydrate interactions. It is structured outside the plasma membrane of the plant cells. 

How is a new cell wall formed by dividing plant cell?

There are few steps that can be established in learning the formation of cell wall in plants:

Step 1: 

The middle lamella gets deposited first during the phase of cytokinesis and then the primary wall gets deposited on top of the middle lamella.

Step 2: 

The primary cell walls are made of cellulose microfibrils which are aligned at all angles. These Cellulose microfibrils are produced at the site, plasma membrane using the cellulose synthase complex.

Step 3: 

These microfibrils are held together by hydrogen bonds in order to provide the tensile strength. This helps to hold the cells together in order to share the gelatinous membrane known as the middle lamella. The middle layer is made of magnesium and calcium pectates.

Step 4: 

The plants cells interact using plasmodesmata which are identical as interconnecting channels within cytoplasm used in connecting the protoplasts of adjacent cells across the two cell walls. 

Step 5: 

A secondary wall is formed after reaching the maximum size. Here, the cellulose microfibrils are aligned in parallel manner in layers in order to provide a helicoidal structure. 

When cell walls are formed in plant cells?

The cells of plants have their origin through division of cells and the cell wall is formed during the phase of cytokinesis where a new partition is built between the two daughter cells that are to be formed. 

In the cell wall formation, the cell centre wall has to be formed between the two dividing daughter cells. As the cells are highly rigid, the contraction of the edges is not possible. Hence, cell plate formation occurs in the centre during the former metaphase prophase phase, known as cytokinesis. 

plant cell wall formation
Plant cell wall from Wikimedia

What is needed for cell wall formation in a plant?

The cell walls in plants are made up of three main components, callose, cellulose and hemicellulose. These components are bound together by the substance called pectin. Pectin is identified as a sugar polymer with sticky properties. 

The necessary components for cell wall formation are as follows: 

Cellulose

This is established as the sugar chain which acts as the major reinforcement for the cell wall. Cellulose is organized in the form of strong beams within the cell walls called microfibrils. These microfibrils act as the backbone for the cell walls. 

Pectin

It works to keep the components of the cell wall bound to each other and helps in the extension of the cell wall. 

Hemicellulose 

This branches out to connect the cellulose beams and are mostly surrounded by the strings of pectin to ensure a string established network. 

Callose

It is used temporarily in the formation of cell walls but plays a very special role. It stabilises the process of cell wall formation by ensuring that the cellulose and hemicellulose are laid down in a proper manner. 

Proteins

There are various scattered proteins that help in cell wall formation. They help in changing the shape and facilitating the growth of the cell wall. 

Where are plant cell walls synthesised?

Enzymes, sugars, and other types of components needed in the cell wall formation are mostly and actively transported across the plasma membrane in a to and from manner during the diffuse growth. Cellulose, one of the main components of cell walls in plants, are long crystals of glucan chains. These form the microfibrillar foundation of plant cell walls which are synthesised in the plasma membrane. 

The components of the cell walls are transported using the vesicles through cytoskeletal tracks which are microtubules and actin filaments. The Golgi apparatus in plants have been identified to be playing a critical role in the biosynthesis of the cell wall. It is the site for producing cell wall matrix polysaccharides, modifying protein glycosylation, and assembling CSCs. 

Conclusion

In conclusion, it can be stated that cell wall plays an important role in plant and have an extremely complex biosynthesis process which occurs at the stage of cytokinesis of cell division.

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