Apical Intercalary vs. Lateral Meristem

Attribute	Apical Intercalary	Lateral Meristem
Location	Found at the base of the shoot or internode	Found along the sides of the stem or root
Function	Responsible for elongation of the stem or internode	Responsible for increasing the girth or diameter of the stem or root
Cell Division	Primarily adds cells to the base of the shoot or internode	Primarily adds cells to the sides of the stem or root
Types	Apical Intercalary Meristem	Vascular Cambium and Cork Cambium
Plant Parts	Found in grasses and monocots	Found in dicots and gymnosperms

Introduction

Plant growth and development are fascinating processes that involve the activity of various types of meristems. Meristems are regions of undifferentiated cells that have the ability to divide and differentiate into specialized tissues. Two important types of meristems are apical intercalary and lateral meristem. While both contribute to plant growth, they differ in their location, function, and characteristics. In this article, we will explore and compare the attributes of apical intercalary and lateral meristem.

Apical Intercalary Meristem

Apical intercalary meristem is primarily found in grasses and some other monocotyledonous plants. It is located at the base of the internodes, just above the node. This meristem plays a crucial role in the elongation of plant organs, such as stems and leaves. It is responsible for the continuous growth of these structures, allowing plants to reach their full potential height.

One of the key characteristics of apical intercalary meristem is its ability to add cells at the base of the internodes, pushing the older cells upwards. This unique growth pattern enables the plant to elongate without disrupting the existing tissues. Additionally, apical intercalary meristem is responsible for the formation of new nodes, which are essential for branching and the development of lateral shoots.

Another important attribute of apical intercalary meristem is its sensitivity to environmental cues. It can respond to changes in light intensity, temperature, and other factors, adjusting the rate of cell division and elongation accordingly. This adaptive feature allows plants to optimize their growth in response to their surroundings.

Furthermore, apical intercalary meristem exhibits a high degree of plasticity. It can differentiate into various cell types, including parenchyma, collenchyma, and sclerenchyma, depending on the specific requirements of the plant. This versatility enables the meristem to contribute to the structural integrity and functionality of different plant organs.

In summary, apical intercalary meristem is located at the base of internodes, responsible for elongation, formation of new nodes, sensitive to environmental cues, and exhibits plasticity in cell differentiation.

Lateral Meristem

Lateral meristem, also known as cambium, is a type of meristem that is found in the vascular tissues of plants. It is located between the xylem and phloem, forming a thin layer of actively dividing cells. Unlike apical intercalary meristem, which contributes to primary growth, lateral meristem is responsible for secondary growth in plants.

The primary function of lateral meristem is to produce new cells that contribute to the increase in girth or thickness of plant organs. It is responsible for the formation of secondary xylem (wood) and secondary phloem, which play crucial roles in providing mechanical support and transporting water, nutrients, and sugars throughout the plant.

One of the distinguishing features of lateral meristem is its ability to produce cells in two different directions. The vascular cambium, a type of lateral meristem, produces cells towards the inside, contributing to the growth of secondary xylem. On the other hand, the cork cambium, another type of lateral meristem, produces cells towards the outside, leading to the formation of the protective cork layer.

Lateral meristem exhibits a remarkable property called secondary growth, which allows plants to increase their girth over time. This growth occurs in woody plants, such as trees, and results in the formation of annual rings. These rings represent the different growth rates during different seasons, providing valuable information about the age and environmental conditions experienced by the plant.

Furthermore, lateral meristem is responsible for the healing of wounds and the regeneration of damaged tissues in plants. It can produce new cells to replace the damaged ones, ensuring the survival and continued growth of the plant.

In summary, lateral meristem is located between the xylem and phloem, responsible for secondary growth, produces cells in two directions, exhibits secondary growth in woody plants, and plays a role in wound healing and tissue regeneration.

Comparison

While both apical intercalary and lateral meristem contribute to plant growth, they differ in several aspects. Let's compare their attributes:

Location

• Apical Intercalary Meristem: Located at the base of internodes, just above the node.
• Lateral Meristem: Found between the xylem and phloem in vascular tissues.

Function

• Apical Intercalary Meristem: Responsible for elongation of plant organs, formation of new nodes, and branching.
• Lateral Meristem: Contributes to secondary growth, increases girth or thickness of plant organs, and produces secondary xylem and phloem.

Characteristics

• Apical Intercalary Meristem: Sensitive to environmental cues, exhibits plasticity in cell differentiation, and adds cells at the base of internodes.
• Lateral Meristem: Produces cells in two directions (inside and outside), exhibits secondary growth in woody plants, and plays a role in wound healing and tissue regeneration.

Conclusion

Apical intercalary and lateral meristem are two important types of meristems that contribute to plant growth and development. While apical intercalary meristem is responsible for elongation and branching, lateral meristem plays a crucial role in secondary growth and the increase in girth or thickness of plant organs. Both meristems exhibit unique characteristics and contribute to the structural integrity and functionality of different plant tissues. Understanding the attributes of these meristems enhances our knowledge of plant biology and provides insights into the remarkable processes that allow plants to adapt and thrive in their environments.