Parenchyma cells are the type of living plant cells, which are known for healing and repair mechanism, and food storage. Collenchyma cells are known for providing mechanical support to the plants, by protecting the delicate inner part of the plant. Sclerenchyma cells are the matured dead cells and are found in wooden part or hard stem of the plant.
Likewise the humans, who have bones to support their body structure, plants also have certain specialized tissues which help them, by providing support to their structure, protecting the inner parts, giving strength, etc. These three tissues (Parenchyma, Collenchyma, and Sclerenchyma) are considered as the ground tissues of the plants and are known to provide mechanical strength to the plant right from its growing stage to lifelong.
Apart from the above-mentioned points, plant tissues also help in the division of the new cells, and in growing of the new plants. It also helps in various metabolic activities. They also help the tissues of the leaf, stems, and branches in bending and protect from the damage.
Tissues are formed from the group of cells performing a specialized function. Plant are also multicellular organisms, containing numerous cells and each one is assigned for the specific activity. Generally, there are two types of plant tissues, these are Meristematic and Permanent tissues. The permanent tissues are again divided into simple permanent tissue and complex permanent tissues.
In this article, we will be focussing about the three types of simple permanent tissues, which are parenchyma, collenchyma, and sclerenchyma tissues. We will also discuss the ground point on which they differentiate.
Content: Parenchyma Vs Collenchyma Vs Sclerenchyma Cells
|Basis for Comparison
|The living plant cells are originating from ground and protoderm meristem. These type of cells are most abundantly found in plants tissue.
|The type of living plant cells originating from the pro-cambium. The epidermal layers of the plant are made of collenchyma cell.
|The hard and outer part of the stem is made up of the sclerenchyma cells. These are the dead plant cells which originate from ground meristem and protoderm procambium.
|These type of cells are present in every soft part of the plant.
|These cells are found in specific part of the plant like leaves, stems, and petioles.
|It is found in mature parts of the plants or trees.
|Type of cell
|Unspecialized and living cells.
|Specialized cells and living cells.
|Specialized, matured and dead cells.
|There are various shapes of the cells, but generally, they are isodiametric.
|Elongated cells are present.
|Sclereids, elongated and fibre shape.
|Thin cell wall present.
|Uneven cell wall.
|Hard and thick cell wall present.
|The cell wall is made up of cellulose.
|The cell wall is made up of pectin and hemicellulose.
|The cell wall is made up of lignin.
|Intercellular space between the cells
|Less space is present between the cells.
|Absent and so cells are tightly packed.
|Parenchyma cells help in storage of foods, in gaseous exchange, and in photosynthesis.
|Collenchyma cells provide mechanical support and elasticity to the plant.
|Sclerenchyma cells provide mechanical support to the plant. It also supports transportation of water and nutrients to the plants.
Definition of Parenchyma
Parenchyma is the most simple tissues made up of living cells and forming the thin layer called as primary cell wall of the plant. Parenchyma is taken from the Greek word “Parenchyma”, meaning ‘something poured in beside’. In plants, parenchyma cells are widely distributed all over and occur as continuous mass from the stems to roots, leaves, fruits.
Parenchyma cells are responsible for generating many other specialised cells and tissues. Structurally they are isodiametric in shape as they have thin cell walls, due to which they face force and pressure around the walls of the cells and in this condition, the cell increases its volume capacity, in order to equalize the pressure all over the cells.
The walls of the cells are mainly composed of the hemicellulose and cellulose. The parenchyma cells are abundant in organelles like ribosomes, Golgi bodies, Endoplasmic Reticulum, Chloroplast and other content like pigments, starch, fats, proteins. These contents provide the nutrients to the germinating embryo.
Due to their cellular structure, parenchyma plays multiple roles in different parts of the plants. Some of the chief function of the parenchyma cells are storage, transporting, gas exchange, protection, photosynthesis, repairing the damaged tissues and in generating other specialised cells. Thus, parenchyma cells play a vital role in the overall development of the plant, throughout its life.
Definition of Collenchyma
Collenchyma cells are known as for providing the structural support to the cell. They are also living cells, having thick cell walls. The cell walls of the collenchyma cells are composed of the pectin, hemicellulose and cellulose and. The cells have a prominent nucleus with other organelles.
Collenchyma also stores food, prevents the tearing of leaves, it also performs the function of photosynthesis. Collenchyma cells push the plant’s organs for elongation and growth.
These cells are absent in monocots, and even in roots of all the plants, though it is present in the dicot leaves above petiole, leaf veins and midrib. There are three different types of collenchyma cells, which are angular, lacunar, and lamellar.
Definition of Sclerenchyma
As we discussed that sclerenchyma is said as the dead tissues of the plants because it comprises of the hardwood. The secondary walls of the matured sclerenchyma cells are densely thick and contain lignin and hemicellulose. These types of cells are hard, non-growing and non-stretchable and are present in mature stems or bark.
Sclerenchyma is found in many different sizes and shapes, but sclereids and fibres are of main types. Sclereids are found in tissues like xylem, phloem, pith, cortex and periderm. This cell also contributes to the hard covering of nuts and fruits and other seeds too.
Fibres support the plants, as these are elongated cells present in bulk in every part of the plant. Some types of fibres such as leaf, seeds hairs are economically important also as they are used as woven and textile materials.
Key Differences Between Parenchyma, Collenchyma and Sclerenchyma
Given below points will differentiate the three types of ground tissues present in plants, which are parenchyma, collenchyma and sclerenchyma:
- Parenchyma is one of the types of living plant cells originating from ground and protoderm meristem. These type of cells are most abundantly found in plants tissue. Another type of living plant cells originating from the pro-cambium, known as collenchyma cells. The epidermal layers of the plant are made of these cells. Thirdly the hard and outer part of the stem is made up of the sclerenchyma cells. These are the dead plant cells which originate from ground meristem and protoderm procambium.
- Parenchyma cells are found in every soft part of the plant, but collenchyma cells are found in specific part of the plant like leaves, stems, and petioles, whereas sclerenchyma cells are found in mature parts of the plants or trees.
- There are different types of shapes of all the cells, but generally, parenchyma cells are isodiametric, while collenchyma are elongated and sclerenchyma are sclereids, fibre in their shapes respectively.
- Parenchyma has a thin cell wall of their cells, and are made up of cellulose. Whereas collenchyma cells have an uneven cell wall made up of pectin and hemicellulose. There is a hard and thick cell wall present of the sclerenchyma cells, which is made up of the lignin.
- Intercellular space between the cells is present in parenchyma cells, while in collenchyma cells less space is present between the cells and in sclerenchyma cells, intercellular space is absent due to which cells are tightly packed.
- The function of parenchyma cells is in the storage of foods, in gaseous exchange, and in photosynthesis, while collenchyma cells provide mechanical support and elasticity to the plant, the sclerenchyma cells provides mechanical support to the plant. It also supports transportation of water and nutrients to the plants.
We all are aware of the importance of tissues in plants as well as animals, in this article we studied the plant tissues and their specialised functions. Though the plant anatomy also has different categories of tissues like vascular tissue, the epidermis and the ground tissues, above we study only about the ground tissues and how they variate from one another.