👶 Plant Physiology

• Plant physiology is the study of vital or functional activities of plants.
• Stephan Hales is the Father of Plant Physiology.
• And water is essential for these functional activities.

Function of Water

• Water is essential for the germination of seeds and growth of plants.
• Water forms over 90% of the plant body by green or fresh weight basis.
• During the process of photosynthesis, plants synthesize carbohydrates from carbon dioxide and water. Therefore, water is one of the essential components for the plant.
• Water acts as a solvent for fertilizers and other minerals, which are taken up by the plant roots in the form of solution. Thus, water serves as the medium in which plants absorb soluble nutrients from the soil.
• Water serves as medium for transport of chemicals to and from cells.
• Water pressure in plant cells provides the firmness to the plants.
• Aquatic life is possible in water only.
• Water helps in the transpiration, which is very essential for maintaining the absorption of nutrient from the soil.
• Water regulates the temperature and cools the plant.

👉🏻 Thus almost all the functional activities of plants depend on the water relation. Under water relation we study the following points:

• How does water enter in the plant: This function & activity is studied under the heading ‘Osmosis’.
• How does water move-up inside the plant: It is studied under: ‘Ascent of sap’ or `Translocation of sap’.
• How is water lost from the plant: It is studied under ‘Loss of Water’ or ‘Transpiration'.