Short Lyc EPRV RNAs after heterologous virus infection. The short RNA fraction of S.lycopersicum leaves derived from the cultivar "Moneymaker" (MM), a transgenic line of "Moneymaker" (CS3, ) and the cultivar "MicroTom" (MT) was hybridized to TAV (B, D) and IGR (A, C) riboprobes after infecting the plants with PVY (Potyvirus Y; in A, B) or TBSV (Tomato bushy stunt virus; in C, D) that express suppressors of PTGS. Individual plants may show different reactions to virus infection therefore several individuals were infected in each assay. Since a general trend became visible only one representative plant is shown here. C0: bulked leaves harvested before infection; C-: mock infection; TBSV+: infected with Tomato bushy stunt virus; PVY+: infected with Potyvirus Y. Ethidium bromide staining of the major RNA on the gel is shown as a loading control below each blot.