Regulation of ion transport across the pollen tube plasmalemma by hydrogen peroxide

The polar growth of the pollen tube is a key stage in the life cycle of seed plants, which is critical for successful sexual reproduction. One of the most important components of this process is ion transport across the cell membrane coordinated in time and space. Different classes of signal molecules, including reactive oxygen species, as has been found recently, participate in regulation of ion transmembrane transport. In this study, based on the model system of subprotoplasts isolated from pollen tubes, we showed that hydrogen peroxide can regulate two targets located on the plasma membrane: nifedipine-sensitive Ca²⁺ channels and ion transport, both of which control the membrane potential. The interaction of hydrogen peroxide with these targets resulted in an increase in an intracellular Ca²⁺ concentration and hyperpolarization of the plasma membrane. Faster regeneration of the cell wall was a consequence of elevation of the Ca²⁺ intracellular concentration.