Forces Responsible for Transportation in Plants

Transportation is plants occurs as a result of the following forces:

Root pressure

This is responsible for moving or bumping water through very short distances. It allows the formation of a continuous water column which sometimes breaks due to the tension created by transpiration.

Transpiration Pull

Cohesion-tension- transpiration pull model of water transport is applicable in case of long trees and plants. Water is usually lost from the leaves through the stomata. This process is called Transpiration. Transpiration results in driving the xylem sap upwards towards the highest points of a tall tree. When water evaporates due to transpiration, a suctional pull is created which creates a continuous column of water. Few properties of water allows this process to happen like Cohesion, Adhesion and Surface Tension.

• Cohesion: This is the property by which water molecules stick to each other.
• Adhesion: This is the property by which water molecules attach to the wall of the polar surfaces.
• Surface Tension: This property makes sure that the water molecules are attracted to each other in liquid phase more than to water in the gas phase.

All these properties allow the water to rise in the form of small tubes which is known as the capillary action. The small diameter of tracheids and vessels aids in capillarity.

Transportation in plants is a fundamental process that is necessary for its survival. Plants make their food for the process of photosynthesis. This process requires water which is transported from the roots which further absorb the water from the soil. Plants need food for their growth. The flowering and fruit formation also require energy which gets transported from the leaves to the different parts of the plant.