Host range, purification and properties of potato virus T

Abstract

SUMMARYPotato virus T (PVT) infected nine species of tuber‐bearing Solanum, most of them symptomlessly, and as a rule was transmitted through the tubers to progeny plants: two genotypes of S. tuberosum ssp. andigena were not infected. The virus was also transmitted by inoculation with sap to 37 other species in eight plant families. Chenopodium amaranticolor is useful as an indicator host, C quinoa as a source of virus for purification, and Phaseolus vulgaris as a local‐lesion assay host; the systemic symptoms in Datura stramonium, Nicotiana debneyi and in these three species are useful for diagnosis. Attempts to transmit PVT by aphids failed, but the virus was transmitted through seed to progeny seedlings of four solanaceous species, and from pollen to seed of S. demissum.PVT was purified by clarifying sap with n‐butanol or bentonite, followed by precipitation with polyethylene glycol, differential centrifugation and sedimentation in a sucrose density gradient. Purified preparations had an E260/E280 ratio of 1.18 and contained a single infective component with a sedimentation coefficient of 99 S. This component consisted of flexuous filamentous particles of about 640 times 12 nm that showed a characteristic substructure when stained with uranyl acetate. The virus particles contained a single species of infective single‐stranded RNA, of molecular weight 2–2 times 106 daltons, and a single species of polypeptide of molecular weight about 27 000 daltons.PVT is serologically related to apple stem grooving virus but not to four other common potato viruses with flexuous filamentous particles. Apple stem grooving virus and PVT cause similar symptoms in several hosts, but also differ somewhat in host range and symptomatology. Apple stem grooving virus did not infect potato, caused additional symptoms in C. quinoa also infected with PVT, and its particles did not show the structural features specific to PVT. The two viruses are considered to be distinct. The cryptogram of PVT is R/1:2–2/(5): E/E: S/C.

Properties of RNAs and Proteins of Apple Stem Grooving and Apple Chlorotic Leaf Spot Viruses

“…wt. 27K) (Salazar & Harrison, 1978), and differ from those of ACLSV. We support the proposal that ASGV and PVT should be removed from the closterovirus group and classified into a new virus group (Bar-Joseph & Murant, 1982).…”

Tepovirus, a novel genus in the family Betaflexiviridae

“…Seed-transmission has also been observed in Datura stramonium and Nicandra physaloides. No vectors are known; there is no transmission by aphids [15].…”

“…It was first classified as a possible member of the ''taxonomic group'' Closterovirus [11], but because of its distant serological relationship to apple stem grooving virus (ASGV) [15], the type member of the ''taxonomic group'' Capillovirus, it was later assigned to this group as a definitive member [4]. Sequencing of the 3 0 end of the viral genome [12] revealed a structural similarity to that of members of the genus Trichovirus, suggesting its re-classification as a member of a definitive trichoviral species [5,8].…”

“…The virus has no known vector, is pollen-and seed-borne, and is readily transmitted by inoculation of sap to a restricted range of experimental hosts [15,16].…”

Complete sequence of an infectious full-length cDNA clone of citrus tatter leaf capillovirus: comparative sequence analysis of capillovirus genomes

“…Their taxonomy has been unclear due to a lack of information other than on morphological features (Coffin & Coutts, 1993). The capillovirus genus includes apple stem grooving virus (ASGV; Lister, 1970), the type member of the group, potato virus T (PVT; Salazar & Harrison, 1978), citrus tatter leaf virus (CTLV; Nishio et al, 1989), lilac chlorotic leaf spot virus (LCLV; Brunt, 1978) and Nandina stem pitting virus (NSPV; Ahmed et al, 1983).…”