Root parts and their functions

As we have just mentioned, the root of the plant fulfills several differentiated functions , the main three of which are: absorption, fixation and conduction.

• Absorption consists of the assimilation of water and nutrients present in the soil through the root hairs of the root, which have the ability to absorb the substances that the plant needs. We recommend that you also know everything about Plant Nutrition with this other article.
• Fixation is carried out by the entire root organ and it is simply a matter of offering a firm anchoring to the plant on the surface it is on. Usually this anchoring will be done in the ground or substrate, although some plants are fixed to other surfaces such as rocks or even other plants. Larger plants, such as tall trees, need deep and broad root systems to provide sufficient stability.
• Conduction , which is the transport of water and minerals from the root hairs to the stem, which will take them where they are needed.

The structure of the root comprises different general parts, easy to differentiate:

• Neck: to begin with, the part immediately buried below ground level is called the neck and is responsible for connecting the rest of the root system with the stem.
• Branching area: after the neck we find the branching area. It is located between the neck and the hairy area, and is characterized by being the area where the roots branch out and create secondary roots with which to increase the land they cover.
• Hairy area: it is found in the youngest areas of the root. In it are the absorbent hairs that are responsible for absorbing water and minerals. These have a life of up to three weeks and consist of a single cell. They are constantly formed at the end of the root, so those farthest from the end are longer. They can be arranged in a density of up to 2,000 hairs per cm2 and measure up to 1,500 microns in length.
• Meristem: next to the hairy area, we find the meristem or cell division area, which is where the growth of the root itself occurs.
• Caliptra: finally, the cap is the end of the root. It is a kind of soft cover, whose function is to protect the root while it makes its way through the subsoil. Its botanical name is Caliptra, and it is very difficult to differentiate with the naked eye. It is found around the meristematic tissue, which is growing, mechanically protecting it from friction and damage that the subsoil could cause. Due to the wear it suffers, caused by friction between the root and the soil, its cells are constantly destroyed, but are replaced at the same rate by those produced in the cell division zone or meristem.

In the scheme of the cover you will be able to see well these parts of the well differentiated roots. These are the most general parts of the root, but in a more specific sense, the parts of the root differ in another way, more specifically, according to the types of root tissues :

• Epidermis: it is the most superficial layer of the root: its skin, as the name suggests. Its cells produce the root hairs responsible for the absorption of water and minerals.
• Cortex: it is the layer following the epidermis. It is located under this and its most notable objective is to store nutrients in the form of starch. In addition, there are spaces between its cells that allow them to aerate, and therefore respiration.
• Endodermis: in the innermost layer of the cortex and around the vascular tissue we find the endodermis. In it, a substance called suberin is produced, which allows the formation of the caspari band, a kind of waterproof barrier. Thanks to this, the water flows only inwards.
• Vascular cylinder: finally, in the center is the stele or vascular cylinder, with the xylem and phloem adopting different distributions in it according to the characteristics of the specific type of plant.

In this diagram below you will be able to see these root tissues well. In addition, we encourage you to learn more about the Types of plant tissues with this other article.

In addition to the three basic functions of roots, there are other types of roots that fulfill additional or specialized functions.

• The root tubers create thickened areas that function as food reserve , stored in them plenty of nutrients booking.
• Others are capable of releasing certain substances into the soil , either to eliminate competition from other plants or to help in the process of dissolving the soil, making it more fertile and rich.
• Lastly, some plants have the ability to develop a type of underground communication network between their roots. Thanks to it, they can share nutrients when a weak or sick individual needs them.