The genomic RNA of beet western yellows virus (BWYV) contains a potential translational frameshift signal in the overlap region of open reading frames ORF2 and ORF3. The signal, composed of a heptanucleotide slippery sequence and a downstream pseudoknot, is similar in appearance to those identified in retroviral RNAs. We have examined whether the proposed BWYV signal functions in frameshifting ...

Tobacco necrotic dwarf (TNDV) and potato leafroll (PLRV), viruses which are normally phloem-limited and are transmitted by aphids in the persistent manner, were successfully purified using Driselase, an enzyme that macerates plant tissue. Frozen tissue of Physalisfloridana infected with TNDV or PLRV was homogenized in buffer containing Driselase and incubated with shaking. The virus particles w...

A yeast homologous recombination system was used to generate mutants and chimeras in the genome of Potato leafroll virus (PLRV). A yeast-bacteria shuttle vector was developed that allows mutants and chimeras generated in yeast to be transformed into Escherichia coli for confirmation of the mutations and transformed into Agrobacterium tumefaciens to facilitate agroinfection of plants by the muta...

The discrepancy between published sequences of the 5' non-coding regions of RNA of a Scottish (S) and that of Dutch (D), Australian and Canadian isolates of potato leafroll virus (PLRV) was investigated. Reverse transcription followed by amplification by polymerase chain reaction showed that RNA from three distinct Scottish isolates of PLRV contained molecules with 5' ends like that of the orig...

Representative amino acid sequences of the RNA-dependent RNA polymerases of all groups of positive-strand RNA viruses were aligned hierarchiacally, starting with the most closely related ones. This resulted in delineation of three large supergroups. Within each of the supergroups, the sequences of segments of approximately 300 amino acid residues originating from the central and/or C-terminal p...

the use of healthy planting material is an important prerequisite for controlling destructive viral diseases in potato production. virus elimination methods such as meristem culture and thermotherapy are usually used to produce the nucleus stock of healthy planting material. here, we report a new technique of electrotherapy for elimination of two potyviruses, potato virus a (pva), and potato vi...