Wheat dwarf virus, a geminivirus of graminaceous plants needs splicing for replication.

AUTOR(ES)

Schalk, H J

RESUMO

By analysing mRNAs with the polymerase chain reaction (PCR) and by studying in vitro generated mutants we have identified an intron in the genome of wheat dwarf virus (WDV), a geminivirus of cereals. Polypeptides whose expression is essential for the replication of the viral DNA have been defined. They are encoded by two distinct overlapping open reading frames (ORFs). The joining of these two ORFs by deletion of the intron as well as the introduction of a frameshift mutation within the intron do not prevent replication of the viral genome in suspension culture cells. In contrast to WDV, the geminiviruses of dicotyledonous plants possess a single continuous ORF, highly homologous to the two individual ones of WDV. We propose that mRNA splicing is a common feature of all geminiviruses of the Gramineae and might contribute to their host class specificity. The existence of a functional intron is a novel finding for the plant viruses.

Documentos Relacionados

• Transcript mapping reveals different expression strategies for the bicistronic RNAs of the geminivirus wheat dwarf virus.
• Replication of wheat dwarf virus DNA in protoplasts and analysis of coat protein mutants in protoplasts and plants.
• DNA forms of the geminivirus African cassava mosaic virus consistent with a rolling circle mechanism of replication.
• Coordinate regulation of replication and virion sense gene expression in wheat dwarf virus.
• Wheat dwarf virus vectors replicate and express foreign genes in cells of monocotyledonous plants.