Serological Relationships among Tombusviruses

Abstract

SUMMARYSerological differentiation indices (SDIs) based on serum titrations in agar-gel double diffusion tests were determined for all ten definitive tombusviruses known at presen t, namely artichoke mottled crinkle, carnation Italian ringspot, cymbidium ringspot, eggplant mottled crinkle, Moroccan pepper, pelargonium leaf curl, petunia asteroid mosaic, the BS3 and type strains of tomato bushy stunt, and tombus Neckar viruses. More than 2000 titrations using 222 antisera from 36 rabbits were done. The SDIs ranged from 1 to >9, and all intermediate values were found. Simple trigonometry and computer methods were used to classify the results. There was no correlation between the serological relatedness of the particles of these viruses and the homology of their genome nucleic acids previously assessed by hybridization tests. In this respect they resemble the tymoviruses but not the tobamoviruses. The electrophoret~c migration of the particles of 12 tombusviruses was studied in 1 ~ agarose con:taining 20 mM-phosphate buffer pH 7.0. Some serologically indistinguishable tombusvirus strains migrated at different rates.

Nucleotide sequence, genomic organization and synthesis of infectious transcripts from a full-length clone of artichoke mottle crinkle virus

“…et al, 1985). Most of the definitive members of the tombusvirus group are serologically related (Koenig & Gibbs, 1986;Martelli et al, 1988) with a few exceptions, one of which is cucumber necrosis virus (CNV) (Rochon & Tremaine, 1988). The determination of three tombusvirus genomic sequences, those of tomato bushy stunt virus-cherry strain (TBSV-cherry;Hearne et al, 1990), cymbidium ringspot virus (CyRSV; Grieco et al, 1989 a) and CNV (Rochon & Tremaine, 1989), has been reported.…”

Nucleotide sequence of the coat protein gene of pelargonium leaf curl virus and comparison of the deduced coat protein amino acid sequence with those of other tombusviruses

“…RNA/cDNA hybridization tests have given conflicting results on the degree of relationship among individual tombusviruses. Data published by Gallitelli et al [6] suggested that there is no correlation between the estimates on genome homology and those on serological relatedness [18]. Serologically closely related viruses often seemed to have only relatively little genome homology and vice versa.…”

“…It is a member of the tombusvirus group which was established in 1971 [10]. Most of the first tombusviruses to be described affect ornamentals, vegetables, and woody plants and are serologically more or less closely interrelated [13,18]; however, those described more recently, cymbidium ringspot virus (CybRSV), cucumber necrosis virus (CNV) [23], and two viruses recently isolated from surface waters, namely Neckar river [20] and Sickte water-borne viruses [21], are serologically only very distantly or not at all related to the …”

“…Average serological differentation indices (SDIs), i.e., the numbers of twofold dilution steps separating homologous and heterologous titres of antisera [29,16], have been used to assess the extent of serological relatedness between individual tombusviruses and to establish a serological classification scheme [18]. RNA/cDNA hybridization tests have given conflicting results on the degree of relationship among individual tombusviruses.…”

Cytopathology in the Identification and Classification of Tombusviruses

“…The identification of individual tombusvi ruses is based primarily on serology [Koenig and Gibbs, 1986], although other means of differentiation, such as the extent of genome homology, have proved useful [Gallitelli et al, 1985]. However, no correlation appears to exist between serological data and estimates of genome homology.…”