title: Defective DNAs of beet curly top virus from long-term survivor sugar beet plants.
abstract: Long-term surviving sugar beet plants were investigated after beet curly top virus infection to characterize defective (D) viral DNAs as potential symptom attenuators. Twenty or 14 months after inoculation, 20 D-DNAs were cloned and sequenced. In contrast to known D-DNAs, they exhibited a large range of sizes. Deletions were present in most open reading frames except ORF C4, which encodes a pathogenicity factor. Direct repeats and inverted sequences were observed. Interestingly, the bidirectional terminator of transcription was retained in all D-DNAs. A model is presented to explain the deletion sites and sizes with reference to the viral minichromosome structure, and symptom attenuation by D-DNAs is discussed in relation to RNA interference.
authors: Biologisches Institut, Abteilung für Molekularbiologie und Virologie der Pflanzen, Universität Stuttgart, Pfaffenwaldring 57, D-70550 Stuttgart, Germany.
authors: Judith
authors: J
authors: Bach
authors: Biologisches Institut, Abteilung für Molekularbiologie und Virologie der Pflanzen, Universität Stuttgart, Pfaffenwaldring 57, D-70550 Stuttgart, Germany. Electronic address: holger.jeske@bio.uni-stuttgart.de.
authors: Holger
authors: H
authors: Jeske
mesh_terms: D027461:Beta vulgaris / Q000821:virology*; D004279:DNA, Viral / Q000235:genetics / Q000302:isolation & purification*; D003673:Defective Viruses / Q000235:genetics / Q000302:isolation & purification*; D017791:Geminiviridae / Q000235:genetics / Q000302:isolation & purification*; D005814:Genes, Viral; D017384:Sequence Deletion
chemical_list: D004279:DNA, Viral
keywords: Beet curly top virus (BCTV); Beta vulgaris L. (sugar beet); Chromatin; Defective DNA