Everything You Should Know about Plant Tissues and their Functions
Observed under a microscope
It is basic biological knowledge that the human body is made up of several atoms, cells and tissues. Not just human beings, but every living organism on this earth shares these basic constituents of life.
Plants, too, fall under the category of living organisms. So, just like animals and human beings, plants too are made up of several different collections of atoms, cells and tissues?
But, what are Tissues?
Tissues are pretty much the basic component that every living organism is made up of. The concept of tissues seems to be confusing but is not. So, let’s get back to some elementary school level biology, shall we?
As most of us know, cells are the most basic and are the smallest unit in any living organism. These cells are what make up an entire human body, or that of any other living organism. In the simplest of words, we are all made up of certain collections of cells. One collection of cells makes up for a tissue.
There are several collections of cells dedicated to the creation and functioning of different parts of the body. Each collection of cells deals with several components of the living organism. These collections of cells are referred to as tissues, in the plural. Multiple tissues work together to create well-functioning organs in living beings.
Example of Plant Tissue Types
Can be divided into different types
Plants too, form an evident part of living beings. They too have several tissues working to serve different functions and purposes related to the plants.
When it comes to plants, there are three different kinds of plant tissue systems.
- Ground Tissue: Deals with the manufacture of nutrients through photosynthesis and storage of nutrients.
- Epidermis: Consists of cells that form the upper layer of leaves and that of the young plant body.
- Vascular Tissue: Concerned with the internal transmission of fluids and nutrients in the plant.
Plant Tissues and their Functions
Different tissues are dedicated to different functions in the living organism. In the case of plants too, the plant tissues carry out different functions essential for the growth and survival of the plants.
In general, the plant tissues can be divided into two different types-
- Meristematic Tissues
- Permanent Tissues
Meristematic Tissues in Plants
Consists of actively dividing cells
Meristematic tissues in plants are made up of several actively dividing cells that aid in the growth of the plant. These cells have thin elastic primary cell walls made of cellulose and are mostly concerned with the increase in the thickness and length of plants.
There are three different components of Meristematic tissues in plants.
- Apical Meristem: The Apical Meristem is concerned with the increase in the length of the stems and roots in the plants. This means that the Apical Meristem is responsible for the primary growth of the plants, and also for the linear growth of the plant organs.
- Lateral Meristem: The lateral Meristem mostly comprises the dividing cells. These dividing cells of the Lateral Meristem lead to an increase in the girth and diameter of organs, thus leading to secondary growth of the plants.
- Intercalary Meristem: The Intercalary Meristem is present on the leaves and the base of nodes and internodes. The Intercalary Meristem consists of cells that are responsible for branch formation, growth of internodes and increased length of plants.
Meristematic tissues have a quite thin cell wall and are often of a spherical, polyhedral or rectangular shape. To properly serve its purpose, Meristematic tissues in plants are present at areas of primary growth in the plant, which are the tips of stems and roots.
Permanent Tissues in Plants
Permanent tissues consist of active or dead cells that are not actively dividing. These are basic cells of the Meristematic tissue that have lost their ability to actively divide and remain fixed at one spot in the plant. This process of taking shape into a permanently fixed position by the cells is also often referred to as Cell Differentiation.
Permanent Tissues can be divided into two different plant tissue types- simple permanent tissues and complex permanent tissues.
Simple Permanent Tissues
Can be categorised into 3 types
Similar permanent tissues consist of cells that have a similar function, origin and structure. The simple permanent tissues can be further divided into three types.
- Collenchyma: The Collenchyma tissues are made up of several thin-walled tissues that are mostly made up of cellulose, pectocellulose and water. The cells in the Collenchyma tissue are tightly packed with very little intercellular space.
The Collenchyma tissues mostly act as a support system for young plants as it is mostly responsible for the elasticity, mechanical support and tensile growth of plants. These cells also help to manufacture sugar and store it as starch in the plant body. The Collenchyma cells are mostly present in the hypodermis of the leaves and stems.
- Parenchyma: The Parenchyma tissues are a collection of different living yet unspecialized cells in the plant body. These cells have thin cell walls, are isodiametric in shape and are loosely packed, with an ample amount of intercellular space among the cells.
The Parenchyma tissues are mostly concerned with providing support for the plant and the storage of food. Chlorenchyma, a special kind of parenchyma, consists of chlorophyll and aids in the process of photosynthesis. Aerenchyma, a kind of Parenchyma present in aquatic plants, makes the plants buoyant, helping them sustain in water.
- Sclerenchyma: Unlike the Parenchyma, the Sclerenchyma tissue is made up of dead cells. These dead cells are thick-walled, with a thick and hard secondary wall as well. The Sclerenchyma tissue mostly deals with providing mechanical support to the plants.
The Sclerenchyma tissues are lined with a thick deposition of lignin that makes the cell walls rigid, strong and impermeable to water. The cells are tightly packed and have no intercellular space among them.
Complex Permanent Tissues
Deal with the transmission of food and water
The Complex Permanent Tissues consist of cells that have a similar origin and work together as part of one unit. There are two common types of permanent tissues in plants.
- Xylem: The Xylem in plants is responsible for the transportation of water and other inorganic solutes in the plant body. Also known as wood, the Xylem consists of four different kinds of cells- tracheids, vessels, xylem fibres (also known as xylem Sclerenchyma) and xylem parenchyma. The Xylem is constructed in a tubular form and is present towards the main axes of the roots and stems of the plant.
- Phloem: The Phloem is mostly responsible for the transportation of dissolved food substances to and fro in the plant body. The Phloem consists of several cells with absent secondary cell walls. The phloem consists of four different kinds of cells- companion cells, phloem fibre, phloem parenchyma and sieve tubes.
The Plant Tissue Culture
Aids in the creation of micropropagated plants
The term plant tissue culture generally refers to a host of techniques employed in the maintenance and growth of plant cells, tissues, organs, etc. on a chemically defined nutrient media and in sterile conditions. The Plant Tissue Culture mainly believes that certain cells of the plant can regenerate or produce a whole plant.
Plant Tissue Culture is often used to produce clones, through the method of micropropagation. Micropropagated plants are often a clone of plants that are difficult to grow or propagate.
What are the types of tissue in a plant?
There are different kinds of tissues in plants. They can be divided into categories like Epidermal, Ground, Meristematic, Vascular, etc.
What are plant tissue and its types?
The plant tissues are collections of cells that are dedicated to a common origin or function. Plant tissues can be classified into two general types- Meristematic and permanent.
What is meant by aquatic plants?
The term Aquatic plants are used to refer to plants that grow in water. Examples of aquatic plants are floating hearts, lattice plants, lotus, water lilies, etc.