Root System: Definition, Types, Examples, Morphology, & Functions

Root System In Plants

The underground organ that performs anchorage absorbs water and nutrients, provides support to the plant, and has a variety of roots necessary for improving survival and growth can all be considered as the root system. The root system gives critical stabilization to the plant but also provides access to resources in the soil.

The plant root system is one of the most important factors in plant fitness and development. They help keep the plant upright, preventing them from falling over by binding them securely to the ground. Apart from this, they take from the soil water and elements which are to be used in photosynthesis and growth. Other than that, some roots may store nutrients and energy to develop plant resilience, hence outcompeting or enduring poor environmental conditions.

Types Of Root Systems

The types of root systems are described below-

Taproot System

The taproot system has a primary root that grows downward into the soil, which has smaller lateral roots coming from it. The primary root is strongly attached to the plant, and most of the time, nutrients are stored here. Common examples would be the carrot—where the thick taproot is edible—and the dandelion, whose deep taproot allows access to nutrients from deeper layers of soil.

Fibrous Root System

In the fibrous root system, many roots of about the same size originate from the base of the stem and produce a diffuse network. This root system is very common in upper layers of soils and thus anchors and feeds the plant quite effectively. Examples include grass and wheat, which have shallow, but extensive root systems to prevent erosion and large absorption areas respectively

Adventitious Roots

Adventitious roots come from tissues other than root tissue, e.g. stems or leaves. These roots may serve as additional anchorage or in absorption. The classic example is the banyan tree that forms aerial roots from branches that grow down to the ground and anchor the plant. Corn also forms adventitious roots that help anchor the plant.

Root Structure

The root structure is described below-

External Structure

The external structure is described below:

Root Cap

The root cap makes a covering at the end of the root that protects the sensitive cells of the meristem During this process the root pushes through the soil. It also plays a role in detecting gravity, which guides root growth.

Epidermis

The epidermis is the outermost layer of cells covering the root, which protects the root and allows for the absorption of water and nutrients by increasing the surface area with the help of root hairs.

Internal Structure

The details are given below:

Cortex

This is the tissue found below the epidermis and is composed of parenchyma cells which mainly serve as storage sites and transport water and nutrients from epidermal tissues into the vascular tissues.

Endodermis

It is specialized a layer of cells surrounding the vascular tissues that regulate the flow of water and nutrients into the xylem. It contains the Casparian strip to ensure selective absorption.

Pericycle

The pericycle is the layer of cells just inside the endodermis and gives rise to lateral roots, but it can also contribute to secondary growth.

Vascular Bundles (Xylem and Phloem)

It contains vascular tissues: xylem and phloem, which are in charge of water, nutrient, and sugar conduction. Moves water and minerals from the root to other parts of the plant. The phloem distributes photosynthetic products throughout the plant.

Root Hair

Root hairs are thin elongated cells that grow from the root epidermis, increasing its surface area for water and uptake of nutrients. But highly increase the plant's ability to take up all the necessary nutrients from the soil.

Root Functions

The root functions are described below-

Anchorage

These roots anchor the plant firmly into the soil, thus offering support and stability to the same. This anchorage helps prevent the uprooting of the plant by wind or water.

Absorption Of Water And Nutrients

Absorption of water and nutrients from the soil takes place in root hairs and the cortex of the roots. This becomes the movement of water and dissolved minerals into a root then for transport throughout the vascular system.

Storage Of Nutrients

Some nutrients are stored in roots and often with energy reserves in which case it is normally starches and sugars. Some examples include the storage roots of beets and sweet potatoes.

Conduction

These are the vessels responsible for conducting the water and nutrients obtained from the soil to the rest of the plant. This is extremely important for the proper functioning of the plants, given that most plants are only able to absorb certain compounds through their roots.

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