title: Ambivalent effects of defective DNA in beet curly top virus-infected transgenic sugarbeet plants.
abstract: Beet curly top virus (BCTV) limits sugarbeet production considerably. Previous studies have shown that infections are associated with the generation of defective DNAs (D-DNA) which may attenuate symptoms. Transgenic sugarbeet lines were established carrying a partial direct repeat construct of D-DNA in order to examine whether they are useful as a means of generating tolerance against BCTV. Thirty four independent transgenic lines were challenged. Viral full-length and D-DNAs were monitored by polymerase chain reaction (PCR) or rolling circle amplification (RCA) and restriction fragment length polymorphism (RFLP). The differential accumulation of both DNA species was compared with symptom severity during the course of infection. RCA/RFLP allowed the discrimination of two D-DNA classes which were either derived from the transgenic construct (D(0)) or had been generated de novo (D(n)). The statistical analysis of the results showed that the presence of D(0)-DNA correlated with increased symptom severity, whereas D(n)-DNAs correlated with attenuated symptoms.
authors.affiliation: Biologisches Institut, Abteilung für Molekularbiologie und Virologie der Pflanzen, Universität Stuttgart, Pfaffenwaldring 57, D-70550 Stuttgart, Germany.
authors.forename: J
authors.initials: J
authors.lastname: Horn
authors.forename: S
authors.initials: S
authors.lastname: Lauster
authors.forename: B
authors.initials: B
authors.lastname: Krenz
authors.forename: J
authors.initials: J
authors.lastname: Kraus
authors.forename: T
authors.initials: T
authors.lastname: Frischmuth
authors.forename: H
authors.initials: H
authors.lastname: Jeske
mesh_terms: D027461:Beta vulgaris / Q000276:immunology* / Q000821:virology; D004279:DNA, Viral / Q000096:biosynthesis* / Q000235:genetics / Q000302:isolation & purification; D003673:Defective Viruses / Q000235:genetics* / Q000276:immunology* / Q000302:isolation & purification; D017791:Geminiviridae / Q000276:immunology* / Q000302:isolation & purification / Q000472:pathogenicity*; D005838:Genotype; D021141:Nucleic Acid Amplification Techniques; D010935:Plant Diseases / Q000517:prevention & control* / Q000821:virology; D030821:Plants, Genetically Modified / Q000276:immunology / Q000821:virology; D012150:Polymorphism, Restriction Fragment Length
chemical_list: D004279:DNA, Viral