Introductory Crop Physiology (1+1)

Functions of water in plant system

Water is the main constituent of protoplasm comprising up to 90-95 per cent of its total weight. In the absence of water, protoplasm becomes inactive.

Organic constituents of plants such as carbohydrates, proteins, nucleic acids, enzymes etc. lose their physical and chemical properties in the absence of water.

Water participates directly in many metabolic processes. Inter-conversion of carbohydrates and organic acids depend upon hydrolysis and condensation reactions.

Water increases the rate of respiration. Seeds respire fast in the presence of water.

Water is the source of hydrogen atom for the reduction of CO2 in the reaction of photosynthesis.

Water acts as a solvent and acts as a carrier for many substance. It forms the medium in which several reactions take place.

Water present in the vacuoles helps in maintaining the turgidity of the cells which is a must for proper activities of life and to maintain the form and structure.

Water helps in translocation of solutes.

In tropical plants, water plays a very important role of thermal regulation against high temperature.

The elongation phase of cell growth depends on absorption of water.