What are the Main Functions of the Roots in a Plant

Root systems There are two main types of root systems: tap root and fibrous root system.

Functions of Roots Some functions of roots are given below:

Activity Aim: To observe anchorage by roots Method: Try pulling out a handful of grass from the ground. Observation: It would not be easy to pull out the grass and something would prevent the grass from being pulled out. Carefully dig out some grass and see what prevented the grass from being pulled out. Conclusion: Roots bind soil particles and hold the plant firmly in one place to the ground.

ActivityAim: To observe absorption by rootsMaterials needed: A carrot, a glass of water, and blue colouring agentMethod: 1. Put a carrot in a glass of water containing some blue colouring agent. 2. Leave the carrot in water for some days.

3. Then cut it into half (lengthwise) and look inside.Observation: Blue colouring can be seen from the bottom to the top of the carrot.Conclusion: Water is absorbed by the tip of the carrot and travelled up inside it along with the blue colouring agent.

Root Modifications Roots of some plants are modified to perform additional functions. Let us study some of these modifications and their functions.

The main difference between root system and shoot system is that the root system consists of roots, tubers, and rhizoids of the plant whereas the shoot system consists of leaves, buds, flowers, and fruits of the plant. Furthermore, Root system occurs in the ground while shoot system occurs on the ground.

Root system and shoot system are the two main parts of a higher plant divided based on the relative position on the ground.

Key Areas Covered

1. What is Root System     – Definition, Components, Function 2. What is Shoot System     – Definition, Components, Function 3. What are the Similarities Between Root System and Shoot System     – Outline of Common Features 4. What is the Difference Between Root System and Shoot System     – Comparison of Key Differences

Key Terms

Photosynthesis, Rhizoids, Root System, Shoot System, Stem, Support, Transport, Tubers

What is Root System

Root system represents the underground part of the plant. It includes roots, tubers, and rhizoids.

Root – The major part of the root system is the roots. Two types of root systems can be identified based on the type of plant. They are tap roots and fibrous roots. Tap roots occur in dicots while fibrous roots occur in monocots.

Figure 1: Cotton Roots

Tubers – They are the enlarged, fleshy underground stem, which consists of buds capable of producing new plants.

Rhizoids – They are the horizontal stem from which the adventitious roots grow.

The four main functions of the root system are absorption of water, fastening of the plant body to the ground, storage of food and nutrients, and prevention of soil corrosion.

What is Shoot System

Shoot system refers to the components of a plant, which grows above the ground. It includes stems, leaves, flowers, seeds, fruit, and buds.

Stem – The main part of the shoot system is the stem. It supports the plant while conducting water and nutrients throughout the plant. There are two types of stems in a plant; herbaceous stem and woody stem. The herbaceous stem is bendable and the woody stem does not easily bend as it is hard.

Figure 2: Root System and Shoot System

Leaves – Leaves are the photosynthetic structures of a plant. The cells in the leaf contain chlorophyll that capture sunlight, which is the source of energy for the production of glucose.

Flower – Flower helps in the sexual reproduction of angiosperms.

Seed – Both angiosperms and gymnosperms produce seeds, which are the reproductive structures.

Fruit – Fruit contains seeds inside it.

Bud – Buds only occur in dicots, developing into a flower or a leaf. The two types of buds are apical bud and auxiliary bud.

Difference Between Root System and Shoot System

The root system refers to the parts of a plant that generally grow beneath the ground, absorbing water and minerals while the shoot system refers to the aerial and erect part of the plant body which grows upwards.

Relative Position to the Ground

Root system occurs beneath the ground while shoot system occurs above the ground.

Growth

Root system grows into the ground while shoot system grows upwards.

Composed of

Root system is composed of roots, tubers, and rhizomes while shoot system is composed of leaves, buds, flowers, and fruits.

Main Function

The main function of the root system of a plant is to absorb water and minerals from the soil while providing support to the plant on the ground. On the other hand, the main function of the shoot system is photosynthesis, transport, and reproduction.

Photosynthesis

Root system does not undergo photosynthesis while shoot system undergoes photosynthesis.

Sexual Reproduction

Root system does not undergo sexual reproduction while shoot system undergoes sexual reproduction by means of flowers.

Timber

The parts of the root system cannot be used as timber while the parts of the shoot system can be used as timber.

Conclusion

The root system is composed of roots, tubers, and rhizoids while the shoot system is composed of stem, leaves, flower, seeds, fruit, and buds. The main function of the root system is to absorb water and minerals from the soil while the main function of the shoot system is to produce food by photosynthesis. The main difference between root system and shoot system is their structure and function.

Reference

1. “The Plant Root System and Its Functions.” CropsReview.Com, Available Here2. “Characteristics of Shoot Systems.” CliffsNotes, Houghton Mifflin Harcourt, 2016, Available Here

Image Courtesy

1. “Primary and secondary cotton roots” (Public Domain) via Commons Wikimedia2. “Plant” By Kelvinsong – Own work (CC BY-SA 3.0) via Commons Wikimedia

Contents

Thanks to the form $ ( , ) $
one can speak of metric relations between roots, in particular of the angle between roots and of the length of a root. It turns out that the magnitude of the angle is independent of the choice of $ ( , ) $,
while if a root system $ R $
is irreducible, then this is also true for the ratio of the lengths of two roots.

Classification of root systems.

and it can be described as the set of algebraic integers of the cyclotomic field generated by a cubic root of unity with norm $ 1 $
or $ 3 $.

In the Western literature one usually says Dynkin graph instead of Coxeter graph, especially in connection with Lie theory. The directed Coxeter graph or simple root diagram is commonly called Dynkin diagram.

How to Cite This Entry: Root system. Encyclopedia of Mathematics. URL: http://encyclopediaofmath.org/index.php?title=Root_system&oldid=44314

This article was adapted from an original article by V.L. Popov (originator), which appeared in Encyclopedia of Mathematics — ISBN 1402006098. See original article

There are two types of root system
Tap root system

Adventitious root system

Types of Root System

1. Tap root system

2. Adventitious root system

Tap root system

It develops from the radicle of the embryo. The radicle grows in to the primary or tap root. It produces branches called secondary roots. These branch to produce what are called tertiary roots. This may further branch to produce fine rootlets. The tap root with all its branches constitutes the tap root system. Tap root system is the characteristic feature of most of the dicot plants.

Adventitious root system

Root developing from any part of the plant other than the radicle is called adventitious root. It may develop from the base of the stem or nodes or internodes. The adventitious roots of a plant along with their branches constitute the adventitious root system.

In most of the monocots the primary root of the seedling is short lived and lateral roots arise from various regions of the plant body. They are thread like and are of equal size and length. These are collectively called fibrous root system. It is commonly found in monocot plants like maize, sugarcane and wheat.

Functions of roots

Roots perform two kinds of function namely primary and secondary function. The primary functions are performed by all the roots in general. In some plants the roots perform certain additional functions in order to meet some special needs. These are called secondary functions of the roots. In order to perform these special functions the roots show modification in their structure accordingly.

: The main function of any root system is absorption of water and minerals from the soil with the help of root hairs.

: The roots help to fix the plant firmly in the soil.

1. Storage of food

2. Additional support

3. Haustorial function

Study Material, Lecturing Notes, Assignment, Reference, Wiki description explanation, brief detail

The root is non-green, cylindrical descending axis
of the plant that usually grows into the soil (positively geotropic). It
develops from the radicle which is the first structure that comes out when a
seed is placed in the soil. Root is responsible for absorption of water and
nutrients and anchoring the plant.

Root is the descending portion of the plant axis.

Generally non-green in colour as it lacks
chlorophyll.

Does not possess nodes, internodes and buds
(Exception in sweet potato and members of Rutaceae, roots bear buds which help
in vegetative propagation)

It bears root hairs (To absorb water and minerals
from the soil)

It is positively geotropic and negatively
phototropic in nature.

Regions of root

Zone of Elongation

Zone of Maturation

Primary root is the direct prolongation of the
radicle. When the primary root persists and continues to grow as in
dicotyledons, it forms the main root of the plant and is called the tap root. Tap root produces lateral
roots that further branches into finer roots. Lateral roots along with its
branches together called as secondary
roots.

Root developing from any part of the plant other
than radicle is called adventitious

It may develop from the base of the stem or
nodes or internodes. Example: Monstera
deliciosa, Ficus benghalensis, Piper nigrum. In most of the monocots the primary root of the seedling is
short lived and lateral roots arise from various regions of the plant body.
These are bunch of thread-like roots equal in size which are collectively
called fibrous root system generally
found in grasses. Example: Oryza sativa,
Eleusine coracana, Pennisetum
americanum.

III. Functions of root

Root performs two kinds of functions namely primary
and secondary functions.

Absorb water and minerals from soil.

Help to anchor the plant firmly in the soil.

In some plants roots perform additional functions.
These are called secondary functions. To perform additional functions, these roots are modified in
their structure.

Storage roots

These are cone like, broad at the base and
gradually tapering towards the apex. Example: Daucus carota.

These roots are swollen in the middle and tapering
towards both ends. Example: Raphanus
sativus

It is very broad and suddenly tapers like a tail at
the apex. Example: Beta vulgaris

Breathing root

Some mangrove plants like Avicennia, Rhizophora,
Bruguiera develop special kinds of roots (Negatively geotropic) for
respiration because the soil becomes saturated with water and aeration is very
poor. They have a large number of breathing pores or pneumatophores for
exchange of gases.

These roots are swollen without any definite shape.
Tuberous roots are produced singly and not in clusters. Example: Ipomoea batatas.

These roots are in cluster from the base of the
stem Example: Dahlia, Asparagus, Ruellia.

In this type of roots swelling occurs only near the
tips. Example: Maranta (arrow root) Curcuma amada (mango ginger), Curcuma longa (turmeric)

Moniliform or Beaded root

These roots swell at frequent intervals giving them
a beaded appearance. Example: Vitis,
Portulaca, Momordica, Basella (Indian
spinach).

These roots have a series of ring- like swelling on
their surface at regular intervals. Example: Psychotria (Ipecac)

Mechanical support

These roots grow vertically downward from the
lateral branches into the soil.

Example: Ficus
benghalensis (banyan tree), Indian rubber.

Stilt
(Brace) root

These are thick roots growing obliquely from the
basal nodes of the main stem. These provide mechanical support.

Example: Saccharum
officinarum, Zeamays, Pandanus,
Rhizophora.

Climbing (clasping or clinging) roots

These roots are produced from the nodes of the stem
which attach themselves to the support and help in climbing. To ensure a
foothold on the support they secrete a sticky juice which dries up in air,
attaching the roots to the support. Example: Epipremnum pinnatum, Piper betel,
Ficus pumila.

In certain trees broad plank like outgrowths
develop towards the base all around the trunk. They grow obliquely downwards
and give support to huge trunks of trees. This is an adaptation for tall rain
forest trees. Example: Bombax ceiba (Red
silk cotton tree), Ceiba pentandra (white silk cotton tree), Terminalia arjuna, Delonix regia, Pterygota
alata.

Vital functions

Some epiphytic orchids develop a special kind of
aerial roots which hang freely in the air. These roots develop a spongy tissue
called velamen which helps in
absorption of moisture from the surrounding air. Example: Vanda, Dendrobium, Aerides.

Roots are produced from the veins or lamina of the
leaf for the formation of new plant. Example: Bryophyllum, Begonia, Zamioculcas.

Sucking or Haustorial
roots

These roots are found in parasitic plants.
Parasites develop adventitious roots from stem which penetrate into the tissue
of the host plant and suck nutrients.

Example: Cuscuta
(dodder), Cassytha, Orobanche (broomrape), Viscum (mistletoe), Dendrophthoe.

Photosynthetic or
assimilatory roots

Roots
of some climbing or epiphytic plants develop chlorophyll and turn green which
help in photosynthesis. Example: Tinospora, Trapa natans (water chestnut), Taeniophyllum.