66. Lateral roots initiate from:
(a) Endodermis
(b) Pericycle
(c) Root apical meristem
(d) Root epidermis

Where Do Lateral Roots Originate in Plants?

In plant development, the initiation of lateral roots is a critical process for enhancing nutrient uptake, anchoring the plant, and adapting to environmental conditions. This process is tightly regulated and originates from specific internal tissues of the primary root.

Correct Answer:

(b) Pericycle

The Role of the Pericycle

The pericycle is a layer of parenchyma cells located just inside the endodermis and surrounding the vascular tissues in roots. It plays a pivotal role in:

• Initiating lateral root primordia

• Contributing to the plant’s ability to expand its root system

• Maintaining meristematic potential, allowing it to divide and form new structures

Lateral root formation begins when pericycle cells re-enter the cell cycle, divide asymmetrically, and form a new meristem that pushes outward through the cortex and epidermis.

Why Not the Other Options?

• (a) Endodermis: While adjacent to the pericycle, it does not initiate root development.

• (c) Root apical meristem: Responsible for primary root growth, not lateral roots.

• (d) Root epidermis: Involved in absorption and protection, not root branching.

Importance of Lateral Root Formation

• Enhances water and mineral uptake

• Increases anchorage and stability

• Enables better adaptation to soil heterogeneity

• Key for agricultural productivity and plant resilience

Conclusion

Lateral roots initiate from the pericycle, making it a key tissue in plant development and root architecture. This knowledge is essential in plant biology, crop improvement, and understanding root system dynamics.