STEPS OF PLANT GROWTH

During the process of plant growth, cells and organs grow in size irreversibly as a result of cell division and enlargement, resulting in an irreversible change in their size. Plant development is the progression of a plant’s life cycle from seed germination to maturation and beyond.

In informal interactions, the terms growth and development are sometimes used interchangeably to denote the same thing. Growth and development, on the other hand, are two distinctly different events in the organisation and production of a mature plant and its body structures, according to scientific principles and definitions. Plant growth and development are extremely time-consuming and difficult processes to understand. Both begin at the time of germination and continue throughout the plant’s whole life cycle.

When you say “growth and development,” what exactly do you mean?

Development is defined as the process of moving from one stage of development to another stage of development during the process of maturity. For example, development occurs when a fully grown plant is generated from a fertilised egg contained within a single cell of an organism. Growth, morphogenesis, and differentiation (the production of tissues with specialised and/or specified functions) are all processes that take place over the course of plant development, among others. It is the interaction of inherited genetic material and the surrounding environment that determines the development of a plant.

Growth, on the other hand, is defined as the permanent change in cell size that occurs as a result of cell elongation. Cell division and elongation are also used to explain the process by which plant organs grow in size as a result of cell division and elongation. For cells to lengthen, there must be a change in the flexibility of their cell walls, as well as an increase in the size of vacuoles and/or the amount of water in the vacuole. Growth can be classified into two categories:

Determinate:

When an organ or a part of or the entire organism stops developing after reaching a specific size, this is referred to as determinate growth. For example, plant leaves and flowers grow in a predictable manner most of the time.

Indeterminate:

An organ, part, or organism is said to be growing indeterminately when the cells of the organ, part, or organism divide indefinitely. Plants grow at an unpredictable rate as a group, according to the literature.

What are the Growth and Development Processes in Plants and How Do They Work?

The following are two important processes that occur during the growth and development of plants:

Differentiation

Undifferentiated cells undergo a process known as differentiation, during which they become cells with specialised functions and distinguishable morphological and physiological properties. All of the cells in a plant’s body share the same genetic make-up as one another. It is only in terms of appearance and physiology that cells of different parts or organs differ from one another. This is due to the way in which the cells undergo differentiation. Differentiation occurs as a result of the overexpression, underexpression, or repression of specific genes. Depending on where the cells are located, they will differentiate in a distinct manner. In the case of roots, cells that are located closer to the ground or a water supply produce the root, whereas cells that are exposed to sunlight form the shoot cells There are no differences between root cells and flower cells, and there are no differences between shoot cells and root cells.

Dedifferentiation:

Dedifferentiation is the polar opposite of differentiation in terms of behaviour. During this process, the mature and differentiated cells of the plant are stimulated under precise conditions to divide and become undifferentiated, resulting in the loss of all of the specialised features that the plant had previously acquired. These dedifferentiated cells undergo a second round of differentiation. When the plant tissues are damaged, it is stated that this has occurred.

Plants, in contrast to animals, grow in an undefined manner. Animals grow and mature until they reach the point where they can no longer grow any further. In the course of their development, the various sections of the animal grow until they reach a size that is dictated by their genetic make-up. However, plants never cease to expand in their capacity. Throughout their lives, they continue to grow and develop. As immature plants get older, the expansion of their meristematic tissues becomes increasingly constrained. Meristematic tissues are young, actively growing and dividing tissues that are present at the apex of the plant’s structure.

What is the process by which tissue grows when plants grow?

The plant’s continual growth patterns result in the production of two types of tissues: vascular tissues and spongy tissues.

1.Primary tissue

2.Secondary tissue

The Primary Tissues: 

For instance, apical meristems

The Secondary Tissues: 

The secondary tissues of the plant are the tissues that are engaged in the lateral growth of the plant. For instance, lateral meristems.

What is Apical Meristem?

These zones of cell division, made up of rapidly dividing cells, are responsible for the growth in height of a plant’s shoot and root regions. Apical meristems are responsible for the increase in height of a plant’s root region. In the primary plant body, it is in charge of the expansion of the length of the plant. This is due to the fact that primary tissues are formed from primary meristems. Apical meristems are composed of cells that are rapidly proliferating and elongating in length. It is feasible to achieve rapid cell elongation in primary tissue cells as a result of the rapid growth of the vacuoles in these cells. As a result, the girth of the stem and roots increases till they reach their maximum dimensions. The elasticity of the cells determines the greatest size that can be achieved. The main cells are unable to develop any further after they have reached their maximal size. Herbaceous plants have only one type of meristem: the primary meristem. This explains why they only develop in axial length, while their girth does not grow in proportion to their axial length.

When it comes to woody plants, however, we can see that they expand enormously in both size and girth. This is due to the fact that the secondary tissues created by the lateral meristems provide both strength and protection to the primary tissues. During the development of the plant, secondary tissues form around the perimeter of the roots and shoots.

What are Plant Growth Regulators, and how do they work?

Plant growth regulators are hormones that are responsible for controlling the growth of plants. A wide diversity of chemical compositions are found in the plant hormones, which are tiny organic molecules with a low molecular weight.

Growth Promoters for Healing Plants:

When a plant is under stress, these plant growth promoters kick in and help it to grow faster. These plant growth stimulants are simple organic chemicals that are created as a result of wounds and/or stresses on plants. Stresses can be of biotic or abiotic origin, depending on their source. Biological agents such as animals, insects, vermin, and other pests are examples of biotic stresses. Abiotic stressors include elements like as temperature, moisture, and other environmental conditions.

Hormones that stimulate plant growth include:

These are simple chemicals known as plant growth promoters, and they work by stimulating the development of plants. Plant growth regulators are composed of a variety of chemical characteristics and chemical structures. Plant growth regulators (PGRs) are substances that aid in the growth of plants. Auxins and cytokines, for example, are plant growth stimulants that are commonly used.

CONCLUSION.

Plant growth happens as the lengthening of the stems and roots of the plant. During the course of their lives, some plants, particularly those that are woody, thicken in both height and width. Growing the length of the shoot and the root is referred to as primary growth, and it is a result of cell division taking place in the shoot apical meristem of the plant.