The Shoot System

Living organisms are generally classified as plants and animals. However, there are various other life forms such as bacteria, unicellular organisms, fungi, viruses, etc. too. These life forms are classified based on the structure of their various systems and what functions they perform. 

Plants are one such lifeform. The plant structure consists of many complex systems that work with each other to keep the plant alive and cause its growth. The shoot system is one such system. 

Plants

Plants are the source of food for many heterotrophic herbivores and indirectly the food source of carnivorous animals who consume herbivorous animals. They are full of nutrition and exhale oxygen, which is essential for life. Plants are made up of many complicated systems that work together and coordinate with each other for the survival and growth of the plant. There are various parts of a plant.

A plant is divided into two primary parts: the part that is buried below the ground; the roots, and the part that shoots up the ground; the stem or the shoot system. The parts of the plant that are buried below the ground are collectively referred to as the root system. Let us study this shooting system.

The shoot system

The shoot system of the plant comprises the parts of the plant that rise above the ground. These parts include buds, leaves, flowering buds, flowering stems, and the main stem. Together they make up the shoot system. The word shoot generally refers to the main stem. As we move from the surface of the stem near the ground to the upper end of the undeveloped shoot, various nodes and internodes can be seen. Let’s see what these nodes and internodes are.

• Nodes: They are the points in the stem through which the leaves grow out. There are as many nodes on a plant as there are leaves.
• Internode: They are placed between the nodes.

There are two types of nodes, as given below.

• Axillary buds

In the crux between the node and the stem lie the axillary buds. These are the dormant nodes that are not developed but have the potential to grow into vegetative branches. The axillary buds remain undeveloped because the plan tries to utilise most of its resources for the terminal bud.

• Terminal bud

This is the main node of the plant on which it focuses most of its resources. It grows out of the apex of the plant. The function of the terminal buds is to grow bigger and taller and facilitate the growth of the plant. However, if any damage is incurred by the terminal bud, the axillary buds that were lying dormant begin to grow and save the life of the plant.

Types of shoot systems

There are various types of plants present in various parts of the world. To survive, they have to adapt to their environment. The shoot systems of the plants have modified themselves into different types to fit with the environment, such as the following.

• Stem tendrils: They are weak and hence take the support of the neighbouring plant to grow.

• Thornes: They are hard structures and act as a defence mechanism and avoid the loss or act as climbing organs.

• Phylloclade: They are flattened, green, and shaped like a cylinder.

Structure of the shoot system

When the shoot system is cut into a transverse cross-section, you can study its anatomy or structure. Let’s take a look at various components of the shoot system. Let’s take the example of the shoot system of the sunflower.

• Epidermis:

The outermost layer of the stem or the shoot system is the epidermis. It is covered with cuticles and bears a lot of hair. The function of the epidermis is to protect the inner structure of the plant.

• Cortex: 

The layer inside the epidermis is called the cortex. The cortex is made up of three distinct layers.

1. Hypodermis: The function of hypodermis is to provide mechanical support
2. Middle layer: Consists of parenchyma
3. Endodermis: It is shaped like a barrel 

• The Stele:

All the tissues of the shoot system that lie inside of the endodermis make up the stele. The tissues are the pericycle, the vascular bundles, the Medullary rays, and the pith. Such is the shoot stem of the sunflower. The shoot systems of the plants are responsible for their growth.

Conclusion:

Plants are the food resources of a lot of organisms. They are made up of many complicated systems that work together in coordination to support the life and the growth of the plant. The plant is divided into two components, basically the root system and the shoot system. The parts of plants that shoot above the ground come in a shoot system. The shoot system includes the stem, leaves, flowers, fruits, and buds. The functions of the shoot system are to support the structure of leaves and the plant, store water, and nutrients for plants, etc.