Plant Biology: Water Importance and Functions

Water

Importance of Water:

• Essential for plant growth and development
• Constitutes about 90% of a plant's tissue
• Necessary for photosynthesis, transportation of nutrients, and temperature regulation

Functions of Water:

• Photosynthesis: Water is the reactant that combines with CO2 to produce glucose and O2
• Transportation of Nutrients: Water helps dissolve and transport nutrients and minerals from soil to plant cells
• Temperature Regulation: Water helps regulate plant temperature through transpiration, evaporative cooling, and heat conduction
• Cell Turgor: Water maintains cell shape and structure, providing mechanical support to the plant

Types of Water Uptake:

• Active Uptake: Plants absorb water through root hairs, using energy from ATP
• Passive Uptake: Plants absorb water through osmosis, using concentration gradients

Water Deficiency:

• Drought: Prolonged water deficiency, leading to reduced growth, wilting, and plant death
• Water Stress: Short-term water deficiency, leading to reduced growth and productivity

Factors Affecting Water Uptake:

• Soil Type: Water availability and uptake affected by soil texture, structure, and moisture content
• Climate: Temperature, humidity, and light affect water uptake and transpiration rates
• Root Depth: Deeper roots can access more water, but may be less efficient in water uptake