FIG. 5.

Packaging phenotype of BMV CP synthesized from FHV replication. (A) Schematic representation of a T-DNA construct of an F2 chimera harboring a BMV CP ORF (BCP). In wt F2, the positions of the start (AUG) and stop (UAG) codons of the FHV CP ORF are indicated. In the F2/BCP chimera, FHV CP was precisely replaced with that of BCP. The lengths of the wt F2 and F2/BCP and the number of nonviral nucleotides left after self-cleavage by the ribozyme (shown in parentheses) are indicated. The positions of the cauliflower mosaic virus 35S promoter, the ribozyme (Rz), and the 35S terminator (T) are identical to those of the T-DNA cassettes of wt FHV genomic RNAs shown in Fig. 1A. (B) The packaging phenotype of FHV progeny by BMV CP expressed in trans (BCP^Trans). N. benthamiana leaves were infiltrated with the indicated mixture of agrotransformants. Agrotransformant B4.1 was coinfiltrated with F1 to provide BCP in trans. Plants infiltrated with F1+F2 served as positive controls. Total and virion RNA profiles were analyzed by Northern blotting hybridization as described in the legend to Fig. 1. The positions of FHV RNA are shown. (C and D) Packaging phenotypes of BCP expressed via either (C) FHV replication (BCP^FHV-Rep) or (D) BMV replication (BCP^BMV-Rep). N. benthamiana leaves were infiltrated with the indicated mixture of agrotransformants. Total (top and middle panels) and virion RNA (bottom panel) profiles were analyzed by Northern blotting hybridization with the indicated riboprobes as described in the legend to Fig. 1. The positions of FHV and BMV RNA are shown at the right. The asterisk indicates a band of unknown origin (see text for details).