Transport of calcium, germanium and rubidium ions in rice seedlings in deuterium oxide.

Deuterium oxide affected all types of transport processes of ions in rice seedlings. The processes of the active transport of Rb+, the passive diffusion of Ca2+, and the preferential and specific absorption of Ge by the seedlings in D2O solutions, were suppressively distorted by D2O. The suppressive effect on the translocation of all ions studied and the absorption of Rb+, was greater with higher concentrations of D2O. However, clear-cut relations of the effect of increasing D2O concentrations on the ion transport were not obtained. The extent of the replacement of H2O by D2O in the plant appeared to affect the movement of ions in the plant.