Visualization of ¹⁴CO₂ gas fixation by plants

Using the real-time radioisotope imaging system (RRIS), we present the carbon dioxide gas fixation process of a soybean plant applying the ¹⁴C-labeled gas. When ¹⁴CO₂ gas was supplied to the selected mature leaf, the fixed carbon, photosynthate, was transferred and accumulated to the younger leaves preferentially within 24 h. When ¹⁴CO₂ gas was supplied to the younger leaves, fixed carbon was hardly moved. In the case of the pods, fixed ¹⁴CO₂ gas in the leaf was preferentially transferred to the closest pod.