THE INFLUENCE OF TEMPERATURE ON THE ABSCISIC ACID STIMULATED WATER FLOW FROM EXCISED MAIZE ROOTS.

The stimulatory effect of ABA on fluid exudation from excised maize roots has been confirmed. The maximum stimulation of water flow by ABA occurred at about 20 °C, and was enhanced by low concentration of the bathing medium. ABA increased the hydraulic conductivity of the root and the activation energy of water permeability was greater in the presence of ABA. It is believed that ABA acts directly at the membrane level, where it forms pores or channels in the membrane; these increase permeability to ions and water. [ABSTRACT FROM AUTHOR]