Definition of Roots, Types, Characteristics, and Functions of Roots

Understanding Roots are part of the plant that is in the soil as a place for the entry of water and minerals from the soil to all parts of the plant. Roots also function to attach and support the body so that it is strong. In some plants, roots are also a place to store food reserves, for example in cassava.

In higher plants, the root system can be divided into two, namely fibrous roots and taproots. The fibrous root system is found in monocotyledonous plant groups, such as rice, corn and bamboo. The taproot system is found in groups of dicotyledonous plants, such as mango, guava and papaya. Roots come from prospective roots contained in the embryo or institution of the seed. Prospective roots that grow into roots are called primary roots, while root growth due to cambium activity will form secondary roots.

Functions and Properties of Roots

Root Function

What are roots? Roots are plant organs. And why are roots important? Because roots have important functions for plants, namely, as follows.

The root functions are:

1. To attach plants to the media (soil) because the roots have the ability to penetrate the soil layer.
2. Absorbing salts, minerals and water, through the root hairs, water enters the plant body.
3. In some plants, roots are used as a storage place for food reserves, for example: in sweet potatoes, potatoes, carrots, and others.
4. In certain plants such as mangroves play a role in respiration.
5. Strengthens the plant
6. Respirator
7. Vegetative means of reproduction
8. Transports water and nutrients that have been absorbed to places in the plant body that need it. Also read: How many Types and Kinds of Roots

Root Properties

Roots have the property that is one part of the plant whose position in the soil can continue to grow. The direction of movement of root growth is influenced by gravity (geotropic) or by water (hydrotropic). Roots can grow through the soil because they have a pointed tip. At a root, there are no visible books that form a segment. Roots are generally pale in color and do not contain chlorophyll, so they cannot carry out photosynthesis.

The properties of the roots are:

1. Is the part of the plant that is usually found in the soil, with the direction of growing the center of the earth (geotropic) or towards the water (hydrotropes), leaving air and light.
2. It does not have nodes, it is not segmented and does not support leaves or scales or other parts.
3. Color is not green, usually whitish or yellowish.
4. Grows steadily at the ends.
5. The tip is often tapered, making it easier to penetrate the ground.

What is Root Structure?

The structure of the root can be divided into several types:

1. Root neck or root base (collum), which is the part of the root that is continuous with the base of the stem.
2. The tip of the root (apex radicis), the youngest part of the root, consists of tissues that are still capable of growth.
3. Root stem (corpus radicis), the part of the root that is between the root neck and the tip.
4. Root branches (radix lateralis), which are parts of the root that are not directly connected to the base of the stem, but come out of the main root. And each of them can branch again.
5. Root fibers (fibrilla radicalis), root branches that are smooth and fibrous.
6. Root hairs or root hairs (pilus radicals) are parts of the root that are actually just protrusions of the long outer skin cells of the root. Its shape is like a feather or hair, therefore it is called root hair or root hair. With the presence of these root hairs, the absorption area of ​​the root becomes greatly expanded, so that more water and nutrients can be sucked in.
7. The root cap (calyptra), which is the part of the root that is located at the very end, consists of a network that is useful for protecting the tips of young and weak roots.

Root Anatomy

Anatomy The root tissue consists of four layers:

1. Epidermis (outer layer/outer skin)
2. Cortex (first layer/first skin)
3. Endodermis (the layer between cortex and stele)
4. Stele (central cylinder i.e. middle layer of the root)

Anatomy explanations of the constituent tissues can be seen below:

Epidermis

The epidermis is the outermost layer of the root and consists only of a single layer of cells composed of cells that are close to each other without intercellular spaces and are thin-walled. In relation to the water absorption process, the epidermis is semipermeable and easily permeable to water. In accordance with its function as a protector of the underlying tissue, the epidermis is thickened so that its structure becomes stronger. On the surface of the epidemic, root hairs grow which are protrusions of the epidermis and function to absorb water and necessary nutrients.

Cortex

Cortex is the first layer of skin on the inside of the epidermis consisting of many cells and has a thin cell wall. Inside there are spaces between cells for air storage and gas exchange. The cortex surrounds the central cylinder and serves as a storage area for food reserves. The tissues found in the cortex include parenchyma, collenchyma, and sclerenchyma.

Endodermis

Endodermis terletak di sebelah dalam korteks. Endodermis berupa satu lapis sel yang tersususn rapat tanpa ruang antar sel, dinding selnya mengalami penebalan gabus. deretan sel-sel endodermis dengan penebalan gabusnya dinamakan pita kaspari. penebalan gabus ini tidak dapat ditembus air sehingga air harus masuk ke silinder pusat melalui sel endodermis yang dindingnya tidak menebal, disebut sel penerus air. Endodermis merupakan pemisah yang jelas antara korteks dan stele.

Stele (Central Cylinder)

The central cylinder is a layer located in the middle of the root inside the endodermis. Inside there are wood vessels (xylem) and filter vessels (phloem) which play a very important role in the process of transporting water and minerals. Xylem transports water and minerals from the soil to the leaves, while phloem transports the products of photosynthesis to all parts of the plant body that need it. In addition to being a means of transport, roots also function to strengthen the plant so that it can stand upright where it grows.

In certain plants, roots also function as food reserves. The central cylinder/stele is the deepest part of the root.

Consists of various types of networks:

1. Perskel / Perikambium
Is the outermost layer of the stele. Branch roots are formed from the growth of personnel outwards.
2. Transport Vessels / Vases
Consists of xylem and phloem arranged alternately according to the direction of the fingers. In dicots between the xylem and phloem, there is cambium tissue.
3. Pith
is located in the deepest or in the bundle of transport vessels consisting of parenchyma tissue.