Figure 5.

Northern blot analysis for int98(+)/(−) spliced intronic lariat degradation. Total RNA (7 µg) was extracted from PSTVd-infected and non-infected plants and subjected to long and small RNA analysis using the 3´ part of S. lycopersicum intron (‘-ron’) as a hybridization probe. Hybridization took place at 64°C and the blot was exposed for 72 hrs to phosporimager screen. Actin and U6 hybridization of the stripped membranes served as loading controls. An unexpected band of unknown nature of approximate 1000-nt in size was detected below the 1365-nt GFP pre-mRNA. We suggest that this RNA is most probably reflecting an intermediate splicing product.