Significance of Transpiration

Significance of Transpiration :

Advantages:

i. It removes excess water.

ii. It helps in the passive absorption of water and minerals from the soil.

iii. It helps in the ascent of sap.

iv. As stomata are open, the gaseous exchange required for photosynthesis and respiration is facilitated.

v. It maintains the turgor (turgidity) of the cells.

vi. Transpiration helps in reducing the temperature of the leaf and in imparting a cooling effect.

Disadvantages: if transpiration becomes excessive — for example, in hot, dry or windy conditions where water loss outpaces the rate at which roots can replace it — the plant can wilt and suffer physiological injury, and in severe or prolonged cases this can even lead to the death of the plant.

Transpiration is 'A necessary evil' : This tension between benefit and cost is exactly what led Curtis, in 1926, to describe transpiration as 'a necessary evil'. For stomatal transpiration to occur at all, the stomata have to remain open during the day; but it is precisely because the stomata are open that the gaseous exchange needed for both respiration and photosynthesis is able to take place. If a plant were to stop stomatal transpiration entirely by keeping its stomata permanently shut, that would directly cut off the gas exchange its own photosynthetic and respiratory activity depends on, and its overall productivity would suffer as a direct result. So, for the plant to remain productive, its stomata must stay open, and transpiration — the water loss that inevitably comes bundled together with that open state — simply cannot be avoided. It is a g …