Characterization and transient replication of tomato leaf curl virus defective DNAs.
Distinct subgenomic DNA species known as defective (df) DNA molecules were found in plants infected with tomato leaf curl virus (TLCV). Four df DNAs derived from TLCV Type and Darwin 1 strains were found to contain large deletions that disrupt all of the viral genes required for viral replication, encapsidation and spread. However, the viral origin of replication (ori), including the replication-associated protein (Rep) binding domains, was present in all four df DNAs. Co-agroinfection of leaf strips with tandem repeat constructs of the viral and df DNAs resulted in their replication in the presence of the respective TLCV strain. However, the df DNAs failed to move in whole plants when co-inoculated with TLCV. The df DNAs were shown to be associated with TLCV coat protein, which may indicate encapsidation. Mutational analysis showed the minimum sequence requirements for df DNA replication by TLCV to be the intergenic region containing the Rep-binding domains.
Behjatnia
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CSIRO Plant Industry, Glen Osmond, Australia.
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Rezaian
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D016960:Agrobacterium tumefaciens / Q000235:genetics; D001483:Base Sequence; D053839:Begomovirus / Q000235:genetics* / Q000302:isolation & purification / Q000502:physiology*; D036022:Capsid Proteins / Q000235:genetics / Q000378:metabolism; D017931:DNA Primers / Q000235:genetics; D004279:DNA, Viral / Q000235:genetics* / Q000378:metabolism; D013286:Datura stramonium / Q000821:virology; D003673:Defective Viruses / Q000235:genetics / Q000302:isolation & purification / Q000502:physiology; D005822:Genetic Vectors; D016679:Genome, Viral; D018551:Solanum lycopersicum / Q000821:virology; D009154:Mutation; D010935:Plant Diseases / Q000821:virology; D014026:Nicotiana / Q000821:virology; D014779:Virus Replication / Q000235:genetics
D036022:Capsid Proteins; D017931:DNA Primers; D004279:DNA, Viral