Figure 5.

AtXRN2-GFP and AtXRN4-GFP localization. (A) AtXRN4-GFP was expressed in the ratl-l^ts strain, and GFP fluorescence was compared with DAPI-stained nuclear DNA. The GFP and DAPI images of the boxed cells are shown superimposed (Overlay). (B) Plasmids encoding AtXRN2-GFP and AtXRN4-GFP were used to transform onion epidermal cells by particle bombardment. GFP fluorescence of AtXRN2-GFP and AtXRN4-GFP was compared with that of GFP-GUS, a primarily cytoplasmic protein, and GFP-NIa, which is targeted to the nucleus. The onion epidermal cell images were obtained with a ×20 objective. A ×40 image of AtXRN4-GFP 1 μg is also shown. The arrows indicate the nuclei. (A larger version of Fig. 5. is published as supplemental data on the PNAS web site, www.pnas.org.)