High Speed Translocation of Ions in Seaweeds

Summary Radioisotopes ( 86 Rb or 32 P) injected or applied during short periods of time to different marine algae show by means of autoradiographic method, that a rapid component of translocation exists in these plants (several m · h -1 ). The larger the species (or more convenient for autoradiography with a thin thallus such as Himanthalia elongata or Chorda filum ), the higher are the experimental values obtained. Similarly, the shorter the transport time (between 2 and 10 min), the higher is the value of the speed obtained (extrapolated values may reach 20 to 25 m · h -1 ). In conclusion, the size of the sample, the sensitivity of the method and the experiment time appear to be the limiting factors for a better demonstration of a rapid component of long distance transport.