The main difference between collenchyma and chlorenchyma is that the collenchyma is a type of simple permanent tissue that provides structural support to the plant whereas the chlorenchyma is a type of modified parenchyma, which is photosynthetic.
Collenchyma and chlorenchyma are two types of simple permanent tissue found in plants. Bothconsist of a primary cell wall made up of cellulose. However, the corners of the cell wall are interlocked in collenchyma cells while the corners of the cell walls are not interlocked in chlorenchyma cells.
Key Areas Covered
1. What is Collenchyma
– Definition, Facts, Types
2. What is Chlorenchyma
– Definition, Facts, Occurrence
3. What are the Similarities Between Collenchyma and Chlorenchyma
– Outline of Common Features
4. What is the Difference Between Collenchyma and Chlorenchyma
– Comparison of Key Differences
Key Terms
Chlorenchyma, Collenchyma, Mesophyll, Parenchyma, Simple Permanent Tissue
What is Collenchyma
Collenchyma is a type of simple permanent tissue in plants. It consists of living cells that occur in the sub-epidermal regions. Hence, collenchyma is a type of ground tissue as well. The primary cell wall of collenchyma cells is made up of cellulose. The secondary cell wall only occurs in the corners of the collenchyma cells. Therefore, the cells remain alive. Secondary cell wall is made up of pectin. Collenchyma can be found in the young parts of a plant such as petiole, stems, and leaves, giving strength and plasticity to those parts.
Figure 1: Collenchyma
Four types of collenchyma can be identified based on the thickening of the cell walls;
- Angular collenchyma – Secondary cell wall forming only at the intercellular contact points.
- Tangential collenchyma – The tangential face contains the secondary cell wall in tangential collenchyma. They occur in ordered rows.
- Annular collenchyma – They consist of uniformly thickened cell walls.
- Lacunar collenchyma – They occur in the intercellular spaces of the plant body.
What is Chlorenchyma
Chlorenchyma refers to parenchyma cells with chloroplasts found in the mesophyll of leaves. The main function of chlorenchyma is to fill the spaces while performing photosynthesis. Mesophyll is a soft and spongy material, which occur between the upper and the lower epidermis of the plant leaf. It is the main part in which the photosynthesis takes place. The two types of parenchyma cells in the mesophyll of dicot leaves are palisade parenchyma and spongy parenchyma. Palisade parenchyma contains a large number of chloroplasts; hence they are actively involved in photosynthesis. On the other hand, spongy parenchyma contains spaces between cells, aiding in the gas exchange. In the monocot leaf, cells in the mesophyll are not clearly differentiated into palisade parenchyma or spongy parenchyma. They are oval-shaped cells, which are irregularly arranged and they contain a large number of chloroplasts.
Figure 2: Dicot Leaf Anatomy
Some chlorenchyma occur in the stem as well.
Similarities Between Collenchyma and Chlorenchyma
- Collenchyma and chlorenchyma are two types of simple permanent tissue found in plants.
- Both contain chloroplasts.
- They fill the spaces and help in photosynthesis.
- Both are types of ground tissue.
- They consist of a primary cell wall made up of cellulose.
Difference Between Collenchyma and Chlorenchyma
Definition
The collenchyma refers to a tissue with living cells having unevenly thickened walls and acting as support, especially in areas of primary growth while the chlorenchyma refers to the parenchyma tissue that contains chloroplasts and is photosynthetic.
Type of Tissue
Collenchyma is a simple permanent tissue while chlorenchyma is a modified parenchyma tissue.
Chlorophyll
Collenchyma may or may not contain chlorophyll while chlorenchyma contains chlorophyll.
Shape
The collenchyma cells are elongated and angular in the transverse section while chlorenchyma cells are isodiametric cells.
Secondary Cell Wall
Collenchyma cells undergo secondary cell wall thickening only at the corner of the cells while chlorenchyma does not undergo secondary cell wall thickening.
Cell wall Uniformity
The collenchyma cells consist of a hard, unevenly thickened cell wall while chlorenchyma cells consist of a soft and uniform cell wall.
End walls
The corners of the cell wall are interlocked in collenchyma cells while the corners of the cell walls are not interlocked in chlorenchyma cells.
Occurrence
Collenchyma occurs in the sub-epidermal regions while chlorenchyma occurs in the mesophyll of the leaves.
Function
The main function of the collenchyma cells is to provide mechanical support to the plant while photosynthesis and storage are the functions of chlorenchyma cells.
Conclusion
Collenchyma is a type of simple plant tissue with secondary cell wall thickening only at the corner of the cells. Chlorenchyma is a type of parenchyma with chloroplasts. Collenchyma mainly occurs in the sub-epidermal regions of young plant structures while chlorenchyma mainly occurs in the mesophyll of the leaf. The main difference between collenchyma and chlorenchyma is their structure and the occurrence.
Reference:
1. Arrington, Derrick. “Collenchyma Cells: Function, Definition & Examples.” Study.com, Study.com, Available Here
2. “What Is a Mesophyll? – Definition from MaximumYield.” MaximumYield, Available Here
Image Courtesy:
1. “Plant cell type collenchyma” By Snowman frosty at English Wikipedia – Own work (Public Domain) via Commons Wikimedia
2. “Leaf Tissue Structure” By Zephyris – Own work (CC BY-SA 3.0) via Commons Wikimedia
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