Importance of Transpiration - QS Study
QS Study

Transpiration is important to plants. The importance of transpiration is discussed briefly: –

Ascent of water and cell sap: Transpiration creates a pull on the water column in the xylem vessel (which is called transpiration pull); as a result the water absorbed by the root and cell sap goes upwards.

Conduction of water and minerals to leaves: water and minerals conducted to the leaves by transpiration pull. So water, necessary for photosynthesis and Mg, necessary for production of chlorophyll, conducted to leaves by transpiration. So it can be said that transpiration plays an indirect role on manufacturing food by photosynthesis.

Maintaining proper temperature and release of energy in leaf: Leaves are taking energy from the sun every moment. Only 1 % of this energy is utilized in different reactions. The rest heat energy released by transpiration. If the temperature in leaf does not remain in optimum condition, all the organic activities would have been seized. So this is also a good aspect of transpiration.

Cell division and physical growth: Transpiration indirectly maintains osmosis and thus keeps all the cells rigid. As a result it enhance cell division and development of the organ.

Resistance to Fungal infection: Due to transpiration there deposits certain hygroscopic salts on the leaf surface, which resists fungal infection.

Absorption of CO2 for photosynthesis: Spongy mesophyll cells of leaves receive CO2 from air present in the air spaces, by diffusion. For this the outer layer of the spongy mesophyll should always be wet. The air inside the air spaces absorbs water from here and transpires through stomata.

Excess of transpiration may cause shortage of water in plant. So excess of transpiration is harmful to plants.