Introductory Crop Physiology

Water relations in plants and its role in plant metabolism

Plant Water Relations

• Water is known as the liquid gold or elixir of life and a major constituent of all living cells.
  
• Water content in cell ranges from 70 to 90 per cent.
  
• Water is dynamic in plant. It forms the major constituent of living things (cells) and all the vital processes of the life are carried out in it.
  
• In living tissue, water is the medium for many biochemical reactions and extraction processes.
  
• Inorganic nutrients, photosynthates and hormones are transported in aqueous solution.
  
• Movement of water form soil solution to root, stem and then to atmosphere, this continuous movement from soil to atmosphere is called as soil-plant-atmosphere water continuum [SPAC].
  
• Evaporation of water can control the temperature of leaf on canopy. Soil nutrients are available to plant roots only when dissolved in water.