The effect of Systox on ionic fluxes in excised barley roots

The influence of various concentrations of the thiol isomer of Systox on ionic fluxes in excised barley roots was investigated. For purposes of comparison, treatments with DNP alone, or in combination with the Systox isomer, were included. Rb and Cl absorption, regardless of the external salt concentrations, were progressively reduced as the Systox concentration in the external solution increased. Treatment with Systox did not result in any appreciable increase in the efflux rates of Rb or Cl ions. DNP treatment enhanced the efflux of Rb but not of Cl. The increased efflux was too small to account for the reduced net uptake. A comparison of individual and combined effects of Systox and DNP on ion absorption indicated an independent action of the two inhibitors.