Properties and importance of water to the plant life

1. Plant water relations
Dhole N. A.
Department of Botany,
Digambarrao Bindu ACS College, Bhokar

2. Introduction:
• Water is most important factor for growth, development and all
metabolic process of plant
• All terrestrial plants absorbs water and minerals from the soil by
their root system.
• The root differentiated into three regions, in which root hairs region
helps in the absorption of water.
• The absorbed water minerals is transported to upper parts of the
plant.
• The absorbed water is also vaporized through the aerial parts of
plant such as stomata, cuticle and lenticular transpiration.
• The phenomenon such as osmosis, diffusion, imbibition and
plasmolysis are totally depends on water.
• In soluble forms of all essential and non-essential nutrients are
absorbed by plants which is because of water.

3. Structure and properties of water:

5. • The pure water is colorless and odorless liquid.
• The melting point of water is 0 °C and boiling point is 100 °C .
• The maximum density of water is at 4 °C.
• The latent heat of water is higher than other liquids. (Latent heat: The
energy required to convert liquid water into gas or vapor at constant
temperature.
• Water expands as it freezes and its density decreases. Ex. Ice floats on
river or in oceans.

6. • Cohesive forces of water is very high. (The attraction of molecules
between similar molecules)
• Adhesive forces of water is also high. (The attraction of molecules
between dissimilar molecules).
• Water has high water tension.
• Water is polar solution.
• Water shows liquid, solid and gas state.
• Water is universal solvent.

7. Importance of water to plant life:
• Life of living organism is impossible without water. In plants, each &
every metabolic pathway requires water.
• The colorless properties of water have high importance in hydrophytic
plant life because it allows the light easily for their photosynthesis
process.
• Water required more energy to rise its temperature this property of
water has great importance to plants life in protecting them from high
temperature.
• The conversion of water to vapor from required high energy, this
property enables plant to protect from loss of water in the form of
vapor.
• Water has high importance in plant life because it expands at freezing
point and density decreases. Therefore ice can floats on water and
protects life present in ocean, etc.

8. • Cohesive and adhesive properties of water are of great importance in
absorption and transport of water from base to apex of plant.
• High surface tension of water is responsible for transpiration pull that
facilitates rising up water in higher plants.
• Water is excellent solvent and provide medium for dissolving variety of
substances than other solvents.
• It also helps to the movement of molecules within cell and between two
cells.
• Most of all biochemical reactions of the cell take place in water such as
hydrolysis, hydration and dehydration etc.

9. • Water is essential for the photosynthesis.
• Water helps to maintain the temperature of plant by transpiration.
• Water helps to absorbs minerals (Major and minor).
• In lower and higher plants, water requires for fertilization process.
• Water also helps for dehiscence of sporangia, seed dispersal and
pollination in many plants.
• Water produces many physiological processes in plants such as cell
enlargement, translocations of food material, maintaining the shape of
cell, seed germination, seed emergence etc.
• Water is very important for opening and closing of stomata.

10. Thank you