Lenticels

What Are Lenticels?

Lenticels are specialised pores of the outer layer in plant tissues and occur, by far, most on stems and roots. They facilitate the gas exchange process between the internal plant tissues and the outside environment, which helps the plant take in oxygen and release carbon dioxide.

Structure Of Lenticels

• Location: They are found in the periderm or outer bark of stems and roots.

• Appearance: The lenticels usually appear as small, elongated, or round openings on the surface.

• Composition: Loosely packed, cork-like cells form an irregularly shaped opening.

• Function: Provide a pathway for gas exchange through the outer protective layers of the plant.

Types Of Lenticels

Lenticels can be divided into, according to structure and function in different types of plants. Following are the major types of lenticels and their features:

Corky Lenticels

• Occurs in many woody plants.

• Visible on the plant surface.

• Provides extra protection to the plant.

Non-corky Lenticels

• Occur in herbaceous plants.

• Not visible easily, less prominent.

• Permits good exchange of gases.

Function Of Lenticels

How Lenticels Facilitate the Exchange of Gases:

• Openings: Openings are formed in the bark for gases to diffuse through.

• Gas Movement: Allows oxygen into the plant and carbon dioxide out of the plant.

• Efficiency: These work with the stomata to control the gas exchange.

Role In Respiration

• Oxygen Supply: The required amount of oxygen is supplied to the inner tissue of the plants for cellular respiration.

• Carbon dioxide removal: Promote the removal of carbon dioxide that is produced as a by-product of respiration.

• Support: Provide the inner tissues with the correct amounts of gases required for energy production.

Lenticel Adaptations In Various Environments

• Dry Environments: Lenticels are smaller in size or smaller in number, which reduces the loss of water.

• Wet Environments: The lenticels may be larger in size or increase in number to allow for gas exchange in waterlogged soils.

• Extremes: Specialised lenticels adapt to some extreme environmental stresses, such as high altitudes or saline conditions.

Process Of Lenticel Formation

Formation of Lenticular from the Periderm:

• Initiation: It is initiated with the development of periderm, which includes the cork cambium and cork cells.

• Changes in Cells: The cells of cork cambium undergo differentiation into lenticel cells. Lenticel cells are loosely packed and form gaps between them.

• Maturation: The lenticels mature and become visible with the plant's growth when the bark expands.

Lenticels Vs. Stomata

Differences between Lenticels and Stomata:

• Location: Lenticels occur on the bark of stems and roots, but the stomata are found on the surface of leaves.

• Structure: Unlike stomata, which are small, round, and are surrounded by guard cells, lenticels are large, irregularly shaped openings.

• Function: Lenticels perform the exchange of gases in woody plants.

In contrast, stomata are involved in gas exchange and transpiration, which takes place in leaves.

Similarities

• Gas Exchange: Both provide for gas exchange—the entrance and exit of oxygen and carbon dioxide—in the plant.

• Regulation: Both are concerned with the regulation of respiration requirements and the general health of the plant.

• Adaptability: Both can adapt to environmental circumstances to promote gas exchange maximally.

Role Of Lenticels

Role of Lenticels in Adaptation and Survival of Plants:

• Adaptation: Facilitate the survival of plants in changing environments by allowing required gas exchange.

• Survival: Assist the plants to survive through environmental changes and stresses, such as drought or high humidity.

Agricultural Relevance

• Crop Management: This knowledge regarding the functioning of lenticels would help look after the health of plants and optimize growing conditions.

• Disease Prevention: The study of lenticels helps diagnose and prevent diseases that can be problems of gas exchange.

Some Examples Of Plants With Noticeable Lenticles

• Trees: Lenticels are very visible on trunks and branches of oak, maple, and birch trees.

• Shrubs: Lenticels are very evident on the stems of some shrubs, like honeysuckle.

Lenticels On Different Parts Of Plants

Description of Lenticels on Stems:

• Appearance: It normally appears as small, elevated dots or lines on the surface of the stem.

• Function: Assimilates gases as the plant grows and expands in size.

Location and Function of Lenticels on Roots:

• Location: They are found on the outer part of the roots, mostly on the aerial roots.

• Function: Allow for oxygen uptake in low-oxygen environments and contribute to the general vigour of roots.

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