Metabolism and the absorption of water by root hairs

Direct measurements of water uptake on individual root hairs of intact roots have established new parameters of the absorption of water. They show that the velocity of absorption is not proportional to the water stress. Furthermore, absorption takes place only where the main cytoplasmic mass is located in the cell, while no measurable absorption can be found at regions facing the main vacuole. The effects of CO2, age, metabolites, poisons, indicate that there is an intimate correlation between the intensity of metabolism and the velocity of absorption of water. On the other hand, excretion is associated with low metabolism. These new aspects show that absorption of water is a complex phenomenon involving metabolism.