FIG. 3.

Agrobacterium-infiltrated tobacco could be used to enrich a template-specific BMV replicase. (A) Initiation of minus-strand RNA synthesis by the BMV replicase extracted from barley and tobacco. Replicase assays were performed as described in Adkins et al. (1). The image is from a 12% denaturing polyacrylamide gel. Versions of the wild-type and mutant SLC+8 constructs used in each assay are indicated above the lane of the gel. RNAs CUA and mB have mutations in the clamped adenine motif and the bulge sequence, respectively (17, 45). The standard deviations (S.D.) of the results from this and several other experiments (not shown) are shown in parentheses. (B) Initiation of subgenomic RNA synthesis by the BMV replicase from barley and tobacco. The image is from a 20% denaturing polyacrylamide gel. The wild-type (Wt) RNA is named −20/13. The upper of the two bands has a nontemplated nucleotide added to the newly synthesized RNA (79). The numbers above the gel image denote mutations within the subgenomic core promoter that have been previously characterized in Siegel et al. (79). The symbol “Φ” denotes a reaction with no exogenously provided template. % syn, quantification of both bands normalized to the products in the wild-type core.