Abstract
We present the preparation of 28Mg to study Mg uptake manner by rice root. Since there is no convenient Mg tracer, we prepared 28Mg from a pure Al target irradiated by an α-particle beam. As a result, approximately 1MBq of carrier-free and salt-free 28Mg was purified. Mg uptake velocity of rice was analyzed using seedlings at the third-, fourth- and seventh-leaf stages. Prepared 28Mg was applied to the rice root for a short term (15 to 30min) with low (0.1mM) or high (5.0mM) concentration of Mg in a solution. After sample was washed with cold water, 28Mg distribution was detected by an imaging plate. From the analysis, the Mg uptake rate of the root in the 5.0mM Mg was approximately 6 to 7-fold higher than that in the 0.1mM. To confirm the result more in detail, the uptake analysis was also performed with various concentrations of Mg. The results indicate that Mg uptake systems concentrate Mg when the Mg concentration in the external solution is low, which suggests the high contribution of active Mg transport system in root.
