Redifferentiation

Introduction

After being dedifferentiated, a mature plant cell loses its capacity to divide. This is referred to as redifferentiation. The result of dedifferentiated cells/tissues that lose their capacity to divide is referred to as redifferentiated cells/tissues and the event is referred to as redifferentiation.

However, plant growth and differentiation are open since, for example, the same apical meristem cells give birth to xylem, phloem, fibres and so on, and cells/tissues originating from the same meristem have various morphologies at maturity. The cell placement inside determines the eventual structure at maturity of a cell/tissue coming from the same meristem.

Cells positioned distal to the root apical meristem (RAM) for example, distinguishes as root cap cells, whereas those pushed down to the periphery mature as the epidermis. However, we do not know what is meant by “commitment” as well as “determination.” The terms determination and commitment are used interchangeably.

Body

Redifferentiation in Plants

Redifferentiation is when dedifferentiated cells mature to execute specified roles and lose their ability to divide. For example, secondary phloem, secondary xylem, secondary cortex, cork and so on are formed from interfascicular cambium and cork cambium.

Differentiation, Dedifferentiation, and Redifferentiation in Plant Tissue Culture

Differentiation 

Differentiation refers to the process through which cells mature. A few or large alterations occur in the protoplasm and cell walls of the cells during differentiation. Root apical meristem (RAM), shoot apical meristem (SAM) , cambium cells develop and mature to accomplish distinct roles. Differentiation is the process that results in maturation. They undergo minor or large structural changes in their cell walls and protoplasm. Let’s look at the tracheary element as an example. A tracheary element’s cells lose their protoplasm and develop extremely strong, elastic, lignocellulosic secondary cell walls. These modifications allow the tracheary element to transport water over extended distances even under tremendous stress.

Plants pertain to a separate kingdom, and their differentiation and evolutionary processes differ from those of other kingdoms. Differentiation and development arise in plants in distinct ways than in animals. Plant differentiation is the maturation of cells from the root system, shoot apical meristem and Cambium to execute specialised roles. To put it another way, cellular differentiation is the process by which a cell converts from one cell type to another. This change occurs mostly to generate a more specialised sort of cell. Cells undergo structural changes in their cell wall and protoplasm throughout differentiation processes. For example, to become a tracheary element, the cell must shed its protoplasm. Additionally, the cell must build a highly robust, elastic and lignocellulosic cell wall to carry water and minerals under harsh circumstances.

It is also referred to as the process by which various types of cells split from their progenitor cells and become distinct. Plants have several sorts of fundamental cells and all of these types of cells are responsible for basic plant function. Depending on the conditions, one kind of cell can be changed into another type of cell.

Dedifferentiation

Under specific conditions, a differentiated cell can restore its ability to divide. This is referred to as dedifferentiation. Dedifferentiation may be seen in the formation of interfascicular cambium and cork cambium from completely differentiated parenchyma cells. Under some conditions, live differentiated cells in plants can regain the ability to divide mitotically. Dedifferentiation refers to the collection of events that provide this ability to divide once again. A meristem is a type of dedifferentiated tissue.

Redifferentiation

A mature plant cell loses its ability to divide after being dedifferentiated. This phenomenon is called redifferentiation. When new cells are produced from dedifferentiated tissues that function as meristems, the cells relinquish their capacity to divide and differentiate further. They ultimately develop to perform specialised plant body tasks. Secondary xylem and secondary phloem are the greatest examples for describing the redifferentiation process. The secondary xylem on the inside and secondary phloem on the exterior is formed by the dedifferentiated vascular cambium. Secondary phloem and secondary xylem cells lose their capacity to divide and instead develop to perform specialised activities of the plant body, such as food and water transportation, respectively. The dedifferentiated cork cambium produces phelloderm, a layer of secondary tissues.

Difference between Dedifferentiation and Redifferentiation

Plant Developmental Processes

This comprises all of the changes that an organism undergoes during its life cycle. The life cycle of seeds begins with germination and ends with senescence. This process comprises all of the processes – cell division, cell elongation, differentiation, maturation and so on.

Cell division occurs in meristematic tissues, resulting in cell elongation or expansion. These cells differentiate and mature into mature cells, which then experience senescence (ageing) and eventually die. This is the entire plant growth process.

The developmental process is said to be the sum of growth and differentiation. This process in plants is governed by various elements, some of which are intrinsic, such as genetic and chemical components,  others that are extrinsic, such as light, temperature, nutrients, water, oxygen and so on.

Plasticity refers to the fact that plants pursue multiple routes in response to their environment, at different stages of life and exhibit diverse structures. For example, heterophily is a phenomenon in which the forms of leaves of juvenile plants differ from those of older plants’ leaves. Cotton, coriander and other plants contain this.

Plant Growth Types

1. Primary and Secondary Growth: The mitotic division of meristematic cells at the root and shoot apex lengthens the plant body. This is referred to as primary growth. Secondary growth refers to the process through which the secondary meristem expands the diameter of the plant body
2. Unlimited Growth: Plants’ root and shoot systems develop constantly from germination to death or throughout the plant’s life cycle. It is referred to as ‘unlimited’ or ‘indeterminate’ growth
3. Limited Growth: Once the leaves, fruits, and flowers reach a specific size, they cease growing. This is referred to as ‘limited’ or ‘determinate’ growth
4. Vegetative Growth: Vegetative growth refers to the early growth of a plant that produces leaves, stems and branches but does not produce flowers
5. Reproductive Development: Following vegetative growth, plants produce flowers, which serve as the plant’s reproductive organ. This is referred to as reproductive growth.

Conclusion

Plant growth differs from animal development in several basic ways, including immobile cells, a stiff cell wall and a big central vacuole. Plant growth and cell division are confined to meristems, which are specialised areas of the shoot and root. Plants have the ability to differentiate, dedifferentiation and redifferentiation. Hormonal and genetic variables govern the development and differentiation processes in plants. Plant growth and development can be influenced by phytohormones in both independent and dependent ways. A pool of stem cells is positioned in the apical meristem’s niche, which is the source of the cell system’s self-renewal and maintenance to deliver cells to developed tissues. A complex network of interactions between hormones and other variables keeps cell division and differentiation in check. Mechanisms aid in the perception of the stress signal and allow the plant to respond optimally to it. Plants are frequently subjected to various abiotic and biotic stressors, such as heat, cold, drought, salt and so on. In contrast, biotic stress is caused mostly by fungus, bacteria, insects and so on. Phytohormones are important components of well-developed systems that aid in perceiving stress signals and enable the plant’s best development response.