Transpiration is the process of loss of water in the form of water vapor from the leaves and other aerial parts of the plant
Transpiration has great significance for the plants.
Its main advantages are
- Absorption of water
- Creating Suction force
- Transportation of water
- Transportation of Minerals
- Protection from heat injury
- The evaporation of water during transpiration cools the leaves.
- The result of transpiration is also evaporative cooling, which can lower the temperature of a leaf and prevent denaturation of various enzymes involved in photosynthesis and other metabolic processes.
Absorption of water
- Transpiration influences the rate of absorption of water from the soil.
- Transpiration helps in the ascent of sap by producing a suction force acting from the top of a plant.
- Evaporation from the leaves concentrates cell sap and increases their osmotic pressure.
- This draws water from the cells at the lower levels in a sequential manner (ascent of sap) and finally favors absorption of water from the soil by the roots.
- As the water evaporates from the leaves, a suction force is produced at the top of the plant drawing more water up through the stem and making the roots absorb more of it from the soil.
Transportation of water
- Since leaves are present at the tips of all branches and twigs, transpiration from their surfaces
- tends to draw water towards them and thus helps in the distribution of water throughout the plant body.
- By transpiration, water moves upwards and as it passes into the cell vacuoles, it makes the cells turgid. This gives form and shape to cells and plants as a whole.
- Higher the rate of transpiration, greater the rate of absorption of water and solutes from the soil.
Transportation of Minerals
- The water stream moving upwards carries dissolved minerals with it. Transpiration also helps in distributing these minerals throughout the plant.
Protection from heat injury
- Some plants like cacti, retain water by reducing transpiration.This saves the plants from high temperatures and strong sunlight.