Abstract
Beet curly top virus (BCTV) infection is associated with the de novo synthesis of a heterogeneous population of subgenomic viral DNAs. Nicotiana benthamiana plants transformed with a partial repeat of one such subgenomic DNA remained susceptible to infection but produced ameliorated symptoms when agroinoculated with BCTV. Symptom amelioration is associated with the mobilization of subgenomic DNA from the integrated copy. In an attempt to improve the resistance, N. benthamiana has been transformed with a partial repeat of a much smaller subgenomic DNA. However, transgenic plants showed almost no resistance although subgenomic DNA was mobilised from the host genome. To further understand the molecular basis of the interference phenomenon, we compared the ability of BCTV to replicate and accumulate in leaf discs derived from resistant and non-resistant transgenic plants. Both subgenomic DNAs were able to interfere with virus replication but only in case of resistant plants the DI DNA efficiently suppressed viral accumulation.
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References
Frischmuth T, Stanley J: Strategies for the control of geminivirus diseases. Semi Virol 4: 329–337 (1993).
Stanley J, Markham PG, Callis RJ, Pinner MS: The nucleotide sequence of an infectious clone of the geminivirus beet curly top virus. EMBO J 5: 1761–1767 (1986).
Briddon RW, Watts J, Markham PG, Stanley J: The coat protein of beet curly top virus is essential for infectivity. Virology 172: 628–633 (1989).
Stanley J, Latham JR: A symptom variant of beet curly top geminivirus produced by mutation of open reading frame C4. Virology 190: 506–509 (1992).
Stanley J, Latham JR, Pinner MS, Bedford I, Markham PG: Mutational analysis of the monopartite geminivirus beet curly top virus. Virology 191: 396–405 (1992).
Frischmuth S, Frischmuth T, Latham JR, Stanley J: Transcriptional analysis of the virion-sense genes of the geminivirus beet curly top virus. Virology 197: 312–319 (1993).
Hormuzdi SG, Bisaro DM: Genetic analysis of beet curly top virus: examination of the roles of L2 and L3 genes in viral pathogenesis. Virology 206: 1044–1054 (1995).
Stanley J, Frischmuth T, Ellwood S: Defective viral DNA ameliorates symptoms of geminiviruses infection in transgenic plants. Proc Natl Acad Sci USA 87: 6291–6295 (1990).
Stenger DC, Stevenson MC, Hormuzdi SG, Bisaro DM: A number of subgenomic DNAs are produced following agroinoculation of plants with beet curly top virus. J Gen Virol 73: 237–242 (1992).
Frischmuth T, Stanley J: Characterisation of beet curly top virus subgenomic DNA localises sequences required for replication. Virology 189: 808–811 (1992).
Frischmuth T, Stanley J: Beet curly top virus symptom amelioration in Nicotiana benthamiana transformed with a naturally occurring viral subgenomic DNA. Virology 200: 826–830 (1994).
Stenger DC: Strain-specific mobilisation and amplification of a transgenic defective-interfering DNA of the geminivirus beet curly top virus. Virology 203: 397–402 (1994).
Frischmuth T, Stanley J: African cassava mosaic virus DI DNA interferes with the replication of both genomic components. Virology 183: 539–544 (1991).
Sambrook J, Fritsch EF, Maniatis T: Molecular Cloning: A Laboratory Manual, 2nd ed. Cold Spring Harbor Laboratory, Cold Spring Harbor, NY (1989).
Hoekema A, Hirsch PR, Hooykaas PJJ, Schilperoort RA: A binary vector strategy based on separation of vir-and T-regions of Agrobacterium tumefaciens Ti-Plasmid. Nature 303: 179–180 (1983).
Ditta G, Stanfield S, Corbin D, Helinski DR: Broad host range DNA cloning system for Gram-negative bacteria: construction of a gene bank of Rhizobium melioti. Proc Natl Acad Sci USA 77: 7347–7351 (1980).
von Arnim A, Stanley J: Determinants of tomato goldenmosaic virus symptom development located on DNA B. Virology 186: 286–293.
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Frischmuth, T., Engel, M. & Jeske, H. Beet curly top virus DI DNA-mediated resistance is linked to its size. Molecular Breeding 3, 213–217 (1997). https://doi.org/10.1023/A:1009623010404
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DOI: https://doi.org/10.1023/A:1009623010404