AUTHOR CORRECTION
Volume 81, no. 17, p. 9339–9345, 2007. The authors were unable to repeat baculovirus expression of infectious Rhopalosiphum padi virus (RhPV) from AcRhPV6, and the sequence of the infectious clone of RhPV (RhPV6) used for baculovirus expression was found to be incorrect. A mutation in the clone at 2185 nt (deletion of a cytosine) results in a frameshift and an early stop codon in ORF1. The helicase, protease, and the RNA-dependent RNA polymerase (RdRP), which is required for virus replication, are not expected to be produced. Therefore, the clone RhPV6 is highly unlikely to be infectious.
The results reported in this manuscript may be explained by the following. (i) There is evidence for the presence of other viruses in the aphid host (Rhopalosiphum padi). In particular, sequences similar to aphid lethal paralysis virus (Dicistroviridae) and Big Sioux River virus (of which the reported partial structural polyprotein is 70% identical to RhPV at the amino acid level) were detected in R. padi. Complementation between RhPV6 and other viruses present in aphids could have occurred such that the mutant RhPV6 genome was replicated in trans by the RdRP from other viruses. (ii) Tagged primers, which are now deemed essential for accurate detection of positive- and negative-strand dicistrovirus sequences, were not used in this study. (iii) The viral coat protein could have been produced via translation of nonreplicating, noninfectious viral RNA owing to the powerful IRES in the viral genome. A heterologous protease would be required for processing of the polyprotein for assembly of coat proteins with the RNA into virions.
The authors thank Jimena Carrillo-Tripp, Nikki Krueger, and Jeremy Kroemer, Department of Plant Pathology and Microbiology and Department of Entomology, Iowa State University, for resolving the problem. The authors deeply regret any inconvenience that the error may have caused.