Effects of penconazole on plasma membranes isolated from radish seedlings

The triazole derivative penconazole at concentrations from 10 −4 to 3 × 10 −4 M inhibited the plasma membrane H +-ATPase when its activity was assayed both on native membranes and on the partially purified enzyme. The same concentrations of penconazole also inhibited the plasma membrane Ca 2+-ATPase and increased the membrane permeability to ions. A possible dependence of these three effects on the interaction between penconazole and plasma membrane phospholipids is proposed.