Short Notes on the Water Absorbing Organs of the Plant

Roots arc the main water absorbing organs of the land plants and floating hydrophytes certain epiphytic plants absorb water from atmosphere by their hygroscopic hanging roo containing a special tissue called vclamen.

A root consists of five distinct regions based on thick function: root cap, meristematic zone or zone off ceil division, zone of cell elongation, root her zone and zone of maturation.

Root Cap

It is a multicellular cap like structure present at the tip of the root. It protects the growing point of the root. Water of soil solution cannot enter through root cap.

Meristematic zone: It lies just behind the root cap. It consists of small compactly arranged thin walled isodiametric cells having conspicuous protoplast. It adds new cells to the root. Absorption of water is restricted in this region because of dense protoplasm and lack of xylem elements.

Zone of cell elongation:

It lies behind the meristematic region. The zone consists of cells which are elongating and is responsible for the increase in length of the root. Very slow entry of water takes place in this region.

Root hair zone:

It occurs just above the zone of cell elongation. Xylem and phloem are well developed in this zone this zone has thousand of root hairs. Maximum absorption of water takes place in this zone. Root hairs are tubular hair like extension of cpiblcma cells which arc closed at its tip.

The root hairs project almost at right angles to the long axis of the piliferous cells. Root hairs arc meant for absorption of water. They enter into the capillaries of soil particles. Due to high concentration of their cell sap and permeability of cell wall, the)’ draw water from the soil.

Zone of maturation:

The rest of the root lying above root hair zone consists of mature cells which impeds water uptake.