Root

ROOT 

 

  • In dicotyledonous plants, the primary root emerges from the elongation of the radicle and extends into the soil. 
  • This primary root gives rise to lateral roots of varying orders, collectively known as secondary, tertiary, etc. roots.
  • These primary roots and their branches collectively form the tap root system, exemplified by the mustard plant. 
  • In contrast, monocotyledonous plants exhibit a distinct root system.

 

Tap Root System (Dicotyledonous):

 

  • Dicotyledonous plants display a tap root system where the primary root elongates directly from the radicle. 
  • This central root gives rise to lateral roots of different orders. 
  • The combined network of primary and lateral roots constitutes the tap root system. 
  • This structural arrangement is evident in plants like the mustard plant.

 


 

Fibrous Root System (Monocotyledonous):

 

  • Monocotyledonous plants diverge from the tap root pattern. 
  • The primary root in these plants is short-lived and replaced by a multitude of roots that originate from the base of the stem. 
  • This intricate network of roots is referred to as the fibrous root system. 
  • The wheat plant serves as an exemplar of this arrangement.

 

Adventitious Roots:

 

  • Certain plant species, such as grass, Monstera, and the banyan tree, deviate from the conventional root initiation from the radicle. 
  • Instead, they generate roots from various parts of the plant, unrelated to the radicle.
  • These roots are termed adventitious roots and contribute to the plant's unique structural adaptation. 
  • Examples include grasses and the banyan tree.

 

 

Functional Roles:

The root system performs several vital functions for plants:

 

  • Water and Mineral Absorption:

- Roots are responsible for absorbing water and essential minerals from the soil, which are indispensable for plant growth.

 

  • Anchorage and Support:

- The root system ensures proper anchorage, stabilising the plant against external forces like wind and rain.

 

  • Storage:

- Roots serve as reservoirs for storing reserve food materials that can sustain the plant during periods of nutrient scarcity.

 

  • Plant Growth Regulation:

- Root tissues participate in the synthesis of plant growth regulators, contributing to overall growth and development.

Region of Root:

 

  • Root Cap and Protection:

- The root apex is shielded by a protective thimble-like covering called the root cap. 

- Root cap safeguards the tender tip of the root during soil penetration.

 

  • Meristematic Zone:

- Situated above the root cap, a few millimetres away.

- Cells in this zone are small, thin-walled, and densely packed with protoplasm.

- These cells undergo repeated divisions, contributing to root growth.

 

  • Region of Elongation:

- Adjacent to the meristematic zone.

- Cells in this region rapidly elongate and expand, promoting the root's lengthwise growth.

 

  • Region of Maturation:

- Proximal to the region of elongation.

- Cells in this zone differentiate and mature, transitioning into specialised structures.

 

  • Root Hairs and Nutrient Absorption:

- Emerge from the maturation zone, formed by epidermal cells.

- Root hairs are fine, thread-like structures.

- Function as absorptive extensions, enhancing water and mineral uptake from the soil.

 

 

Functions and Significance:

 

  • Root Cap Protection: 

Shields the delicate root apex from potential damage.

 

  • Meristematic Activity:

Facilitates continuous cell division, supporting root growth.

 

  • Elongation and Maturation:

Drives longitudinal growth and cellular specialisation.

 

  • Root Hairs for Nutrient Uptake:

Efficiently absorb water and essential minerals from the soil.