Detection of PYDV transcripts in infected N. benthamiana. Northern gel-blot hybridizations were conducted with ORF-specific probes shown in Fig. 1. 32P-labeled cDNA probes were hybridized to total RNA extracted from PYDV- (lane 1), SYNV-infected (lane 2) or mock-inoculated (lane 3) plants. The relative positions of the PYDV genomic RNA (gRNA) and N, X, P, Y, M, G, and L transcripts are indicated on the right side of this Figure. Ethidium-bromide (EtBr) stained gels at bottom indicate RNA quality and loading for each hybridization. The strong cross-hybridization of the X gene probe with ribosomal RNA