Figure 2. Proximal-to-distal gradient of programmed cell death in the aleurone layers of rice seeds.

The aleurone layers were longitudinally stripped from the rice grains cultured for 5 d, and changes in cells after staining with 8.5 μg mL⁻¹ AO were examined using fluorescence microscopy. Live cells appear green due to AO fluorescence. (A) The intensity changes in AO green fluorescence in the aleurone layer. (B–F) Corresponded to the intensity changes of AO green in the aleurone layers of the distal embryo, adjacent to the distal embryo, middle section of the seed, adjacent to the proximal embryo and the proximal embryo, respectively; the bar represents 20 μm. The assay was performed at least three times and a representative aleurone layer section is shown.