What is transpiration and its role in plants?

Transpiration is the process by which water is lost from the aerial parts of a plant, mainly through the stomata of leaves, in the form of water vapor.

It is a vital physiological process that supports multiple functions in plants.

Process of transpiration:

• Water is absorbed by roots from the soil

• It travels upward through the xylem to the leaves

• Water evaporates from leaf surfaces and exits through stomata as vapor

Role of transpiration in plants:

1. Transpiration pull (water transport)
Transpiration creates a negative pressure that helps pull water and dissolved minerals from roots to leaves.

2. Cooling effect
Evaporation of water cools the plant, preventing overheating, especially in hot conditions.

3. Nutrient transport
Minerals absorbed from the soil are transported along with water to different parts of the plant.

4. Maintains turgor pressure
Helps keep plant cells firm, supporting structure and preventing wilting.

5. Supports photosynthesis
By maintaining water flow and stomatal function, transpiration indirectly supports photosynthesis.

Factors affecting transpiration:

• Temperature (higher → more transpiration)

• Humidity (lower → more transpiration)

• Wind speed

• Light intensity

In simple terms: Transpiration is the loss of water from plants that helps in water movement, cooling, and nutrient transport.