Figure 1.

Comparison of low molecular weight RNA from PSTVd-infected and non-infected tomato and from Nicotiana benthamiana transformed with a [³⁵S]GFP transgene that is undergoing PTGS. All samples were run on the same gel and blotted onto the same membrane. The lanes containing tomato RNA were hybridised with a full length PSTVd(–) RNA transcript. The uninfected control contains an unspecific cross hybridisation signal detected under these low stringency conditions. The lane containing N.benthamiana RNA was hybridised with a full length GFP(–) RNA transcript. Markers were ³²P-labelled mGFP5 RNA, transcribed in vitro and digested with RNase T1. Sizes are indicated to the left of the gel. PTGS-specific RNA is indicated by an arrow to the right of the gel.