Quantitative Analysis of ²⁸Mg in Arabidopsis using Real-time Radioisotope Imaging System(RRIS)

Abstract

We present a quantitative imaging of ²⁸Mg in Arabidopsis using real‐time RI imaging system(RRIS). First, performance of RRIS in quantitative determination was characterized using standard spots. The results showed that the dynamic range for ²⁸Mg determination was three orders of magnitude. Next, quantitative accuracy of measurement was studied for a variety of pant tissues of Arabidopsis. The detection of the β‐rays emitted from ²⁸Mg and its daughter radionuclide, ²⁸Al, was found to be slightly affected by the self‐absorption by the plant tissue. Nevertheless, the degree of the self‐absorption could be determined by the tissue type, indicating that the RRIS can be applied to the quantitative and time‐course analysis of the ²⁸Mg in each tissue type. The ²⁸Mg transport amount in the Arabidopsis shoot tissue was analyzed using the system. It was found that the activity of Mg unloading from vascular tissue was higher in the young stem compared to the old stem.