Effects of K^$(⁸⁶Rb) transport and the net H^$ efflux on electrical properties along bean (phaseolus mungo) roots

The three-phase electric potential distribution along two-day-old intact Phaseolus roots was investigated in relation to cell growth and K^$ and H^$ transports using tracer K^$(⁸⁶Rb) and pH experiments. The activity of a radial electrogenic component located between the cortical cells and the external solution was high in the elongating region and in the completely matured region. The activity of another radial electrogenic component located between the cortical cells and the stele was maximal in the elongating region. Both potassium uptake from the external solution into the cortical cells and H^$ excretion took place mainly in these regions.