What is the Difference Between Dermal Vascular and Ground Tissue

The main difference between dermal, vascular, and ground tissue is that the dermal tissue is composed of epidermis and periderm. But, the vascular tissue is composed of xylem and phloem. Meanwhile, ground tissue is composed of parenchyma tissue, collenchyma tissue, and sclerenchyma tissue. Furthermore, dermal tissue provides protection and prevents water loss; vascular tissue conducts water and food, while ground tissue undergoes photosynthesis, food storage, regeneration, support, and protection. 

In brief, dermal, vascular, and ground tissue are three tissue systems of plants. Generally, they organize into different functional layers in the stem, leaves, roots, and other parts of the cell. 

Key Areas Covered 

1. What is Dermal Tissue
     – Definition, Anatomy, Function
2. What is Vascular Tissue
     – Definition, Anatomy, Function
3. What is Ground Tissue
     – Definition, Anatomy, Function
4. What are the Similarities Between Dermal Vascular and Ground Tissue
     – Outline of Common Features
5. What is the Difference Between Dermal Vascular and Ground Tissue
     – Comparison of Key Differences

Key Terms 

Collenchyma, Dermal Tissue, Epidermis, Ground Tissue, Parenchyma, Phloem, Sclerenchyma, Vascular Tissue, Xylem

What is Dermal Tissue 

Dermal tissue is the external tissue responsible for protecting the soft tissue inside the plant body. Also, it controls the interactions of the plat with the surrounding environment. Further, there are two types of dermal tissue, occurring in plants at different developmental stages. They are the epidermis and the periderm. 

Epidermis 

The epidermis is a single layer of closely-packed, parenchymatous cells. Its function is to cover the underlying tissues. Therefore, it serves as the skin of the plant. In addition to that, it secrets a waxy substance called the cuticle, which coats, waterproofs, and protects the above-ground parts of plants. On that account, the cuticle prevents abrasions, water loss, infections, and damages from toxins, respectively.

Figure 1: Leaf Epidermis

Besides, the epidermis contains several types of specialized cells, including pavement cells, guard cells, and hair cells. Of these, pavement cells are large, irregular-shaped parenchyma with no chloroplasts. Also, they make up most of the epidermis. Meanwhile, guard cells are pairs of bean-shaped, sclerenchyma cells that swell and shrink by osmosis to open and close stomata. Here, stomata are the tiny pores, which control the exchange of oxygen and carbon dioxide gases and the release of water vapor. Significantly, the lower surface of leaves contains the highest number of stomata; 100,000 stomata per square centimeter.

Apart from those two cells, the third is the hair cells. And, three types of hair cells occur; epidermal hairs, glandular hairs, and root hairs. Function-wise, epidermal hairs lower the water loss by decreasing the flow of air over the plant surface, while glandular hairs prevent herbivory by storing substances that are harmful to insects. Meantime, root hairs increase water uptake by increasing the surface area of the cell.  

Periderm 

While epidermis is the primary plant tissue, periderm is the secondary tissue, which replaces the epidermis in the stem and roots during the secondary growth of woody plants. Furthermore, periderm composes of three layers of cells, initiated from the cork cambium or phellogen. Of these, the cork cambium produces cork cells outward and phelloderm inwards.

Figure 2: Periderm

Moreover, cork cells undergo secondary wall-thickening with suberin depositions, while phelloderm contains living cells. Also, it provides protection to the internal tissue while permitting gas exchange.  

What is Vascular Tissue 

Vascular tissue includes xylem and phloem, conducting respectively water and dissolved food throughout the plant. In the stem, they arrange in vascular bundles, the distinct strands, which run in length-wise. Specifically, in the dicot stem, vascular bundles occur in a ring while in the monocot stem, they are scattered.  

Xylem 

Xylem is the type of vascular tissue responsible for conducting water and dissolved minerals. Also, it provides mechanical support to the stem. Furthermore, the two types of conducting elements of the xylem are the tracheids and vessel elements. Of these, tracheids are long and have thicker secondary cell walls. But, vessel elements are short and have thinner cell walls. In addition to that, xylem contains parenchyma cells and fibers.

Figure 3: Xylem and Phloem

Phloem 

Phloem is the type of vascular tissue responsible for conducting food from leaves to the different parts of the plant. Here, the conducting component is the sieve-tube cell and its companion cell, which are arranged end to end to make up a long sieve tube. Furthermore, while the sieve-tube cells are alive, the nucleus of it is disintegrated. Therefore, the companion cell provides metabolic support to the sieve-tube cells. Similarly, phloem also contains parenchyma and fibers. 

What is Ground Tissue 

Ground tissue contains the cells produced by ground meristems. And, these cells include parenchyma, collenchyma, and sclerenchyma. Furthermore, the main function of ground tissue is to fill the spaces between the vascular and dermal tissue. Apart from that, the cells of the ground tissue are specialized for various functions including photosynthesis, storage, regeneration, support, and protection. 

Parenchyma 

Parenchyma cells are living cells that perform most of the plant’s metabolism. Therefore, they have only the primary cell wall thickening by cellulose. Also, they have the ability to undergo proliferation. Functionally, the parenchyma in leaves undergoes photosynthesis. In addition to that, parenchyma serves as a storage tissue and undergoes healing and tissue regeneration.

Figure 4: Mesophyll contains Photosynthetic Parenchyma

Collenchyma 

Collenchyma cells are living cells with uneven cell wall thickenings of cellulose and pectin. Also, they have a polygonal shape, and their function is to provide structural support to the young parts of the plant, including stems, roots, and petioles.  

Sclerenchyma  

On the other hand, sclerenchyma is non-living cells with cell wall thickenings of cellulose, hemicellulose, and lignin. Also, there are two types of sclerenchyma cells; they are the fibers and sclereid cells. Typically, fiber cells are long cells that occur in bundles. And, they occur in xylem and phloem. Meanwhile, sclereid cells have highly thickened cell walls with lignin. Also, they occur in small bundles.

Besides, the main function of sclerenchyma is to provide structural support to the different parts of the plant. 

Similarities Between Dermal Vascular and Ground Tissue 

• Dermal, vascular, and ground tissue are three tissue systems of a Plant. 
• Also, all three are permanent tissues, which differentiate and specialize them from the cells produced by the meristem. 
• Therefore, they perform specialized functions by losing their ability to dived further. 
• Besides, these three tissues occur in the stem, leaves, and roots. 

Difference Between Dermal Vascular and Ground Tissue 

Definition 

Dermal tissue refers to the tissue system that protects the internal structures of the plant and control interactions with the plant’s surroundings. Meanwhile, vascular tissue refers to the xylem and phloem, whose function is to transport water and dissolved substances. On the other hand, ground tissue refers to the soft tissue that functions in photosynthesis, storage, regeneration, support, and protection. 

Component Tissue 

While dermal tissue composes of epidermis and periderm, vascular tissue composes of the xylem and phloem. Meantime, ground tissue composes of parenchyma, collenchyma, and sclerenchyma. 

Cell Types 

Dermal tissue contains parenchyma cells. Vascular tissue contains conducting elements, parenchyma, and fibers, but ground tissue contains parenchyma, collenchyma, and sclerenchyma. 

Function  

Dermal tissue provides protection and prevents water loss. Vascular tissue conducts water and food, while ground tissue undergoes photosynthesis, food storage, regeneration, support, and protection. 

Conclusion 

Dermal tissue is the tissue responsible for protecting the internal, soft tissues of the plant. It is composed of epidermis and periderm. Also, the function of the dermal tissue is to provide protection to the internal tissue while preventing water loss. On the other hand, the vascular tissue is composed of xylem and phloem, which are the conducting tissues of the plant. And, they transport water and dissolved food, respectively. Meanwhile, ground tissue composes parenchyma, collenchyma, and sclerenchyma cells, filling the spaces between vascular and dermal tissue. In addition to that, they undergo photosynthesis, storage, and regeneration. Therefore, the main difference between dermal, vascular, and ground tissue is the type of cells present and their functions. 

References:

1. “Concept 3: Plant Tissue Systems|BioCoach Activity.” Pearson – The Biology Place, Available Here.

Image Courtesy:

1. “Leaf Structure” By Zephyris – Own work (CC BY-SA 3.0) via Commons Wikimedia   
2. “Tree secondary components diagram” Автор: Brer Lappin (Public Domain) via Commons Wikimedia  
3. “Plant cell types” By Kelvinsong – Own work (CC BY-SA 3.0) via Commons Wikimedia   
4. “Leaf Tissue Structure” By Zephyris – Own work (CC BY-SA 3.0) via Commons Wikimedia