Real Time Visualization of ⁵²Fe and ⁶²Zn Translocation in the Ear of Rice

Abstract

Iron (Fe) and zinc (Zn) are essential nutrients for plants. However, little is known how Fe and Zn are translocated in rice plants especially to the ears after absorption from roots. We traced ⁵²Fe and ⁶²Zn in rice plants (cv.Nipponbare) of 3 weeks after flowering by the 'PETIS method'. Image of the radioactivity appeared simultaneously in the ear and the flag leaf within 4 hours after supplying ⁵²Fe³⁺-DMA to the roots, suggesting that ⁵²Fe was not translocated to the ear via the flag leaf in short time. Image of the ear of rice appeared within 3.5 hours after supplying ⁶²Zn²⁺ and very little was translocated to the flag leaf during this experiment, suggesting that different from Fe, Zn was preferentially translocated to the ear at maturing stage. Real time translocation of ¹¹C-methionine and ¹³N-NH₄⁺ were also performed in rice plants.