Uptake kinetics of deuteriated water vapor by plants: Experiments of D₂O release in a greenhouse as a substitute for tritiated water

Potted plants were exposed to D₂O vapor in a greenhouse and uptake of D₂O by leaf and deposition of D₂O to pot soil were examined. Atmospheric D₂O concentration in the greenhouse increased rapidly after starting the release and reached constant level in a few hours. Although the variation of D₂O concentration in leaf followed that in air with showing a time delay, D₂O concentration in leaf did not become the same level as that in air and vein showed lower concentration than lamina. D₂O concentration in the pot soil increased slowly with diffusing in deeper layer.