Meristems play a central role in vegetative growth because they are the regions in plants where active cell division takes place. These growing regions continuously produce new cells that develop into roots, stems, and leaves — the main parts of the plant’s vegetative body.
Here’s how meristems contribute to vegetative growth:
- Apical Meristems:
- Found at the tips of roots and shoots.
- Responsible for primary growth, which increases the length of the plant.
- In shoots, they produce new leaves and branches; in roots, they form root hairs and root branches.
- Example: Growth of new leaves at the shoot tip or elongation of roots in soil.
- Intercalary Meristems:
- Located at the base of leaves or internodes (especially in grasses and monocots).
- Help in regrowth after cutting or grazing by animals.
- Allow rapid elongation of plant parts, supporting continuous vegetative expansion.
- Lateral Meristems:
- Found along the sides of stems and roots (e.g., vascular cambium and cork cambium).
- Responsible for secondary growth, which increases the thickness or girth of the plant.
- They produce secondary xylem and phloem, strengthening stems and roots for better support and transport.
- Cell Differentiation:
- The cells produced by meristems later differentiate into specialized tissues such as xylem, phloem, and parenchyma, forming the functional parts of roots, stems, and leaves.
In summary:
Meristems are the growth centers of plants.
- Apical meristems → lengthening (primary growth)
- Intercalary meristems → regeneration and elongation
- Lateral meristems → thickening (secondary growth)
Together, these meristems drive continuous vegetative growth, enabling the plant to expand, strengthen, and prepare for later reproductive development.