Cover photograph (Copyright © 2003, American Society for Microbiology. All Rights Reserved.): Green fluorescent protein (GFP) fluorescence in a Nicotiana benthamiana leaf 2 days after infection with tobacco rattle virus (TRV) modified to express GPF. The image was produced under UV light, and the red fluorescence is due to chlorophyll. The TRV expression system was used to express the nonstructural proteins of cowpea mosaic virus in planta. (See related article in June 2002: vol. 76, issue 12, p. 6293.)