Characterization of a pothos (Scindapsus aureus) virus with unusual properties

Abstract

A virus for which the name of pothos latent virus (PoLV) is proposed, was isolated by inoculation of sap from symptomless plants of Scindapsus aureus. PoLV had isometric particles c. 30 nm in diameter, a monopartite genome consisting of a non polyadenylated, single-stranded RNA molecule c. 4,300 nucleotides in length, constituting c. 17% of the particle weight, and a single type of coat protein subunit with a M~ of c. 40,000 Daltons. The biological properties (host range reactions) of PoLV resembled those of Tombusviridae for it infected most of the artificial hosts locally, inducing symptoms recalling those elicited by several species of the above family. Like tombus-and carmoviruses, PoLV had two subgenomic RNAs which, however, differed in size from those of both genera. The dsRNA pattern was also distinctly different. Cytopathological features recalled those of tombusviruses except for the lack of multivesicular inclusion bodies. PoLV was serologically related to, but distinct from two Carmovirus (i.e., galinsoga mosaic and Ahlum waterborne viruses) and three Tombusvirus species (i.e., eggplant mottled crinkle, Sikte waterborne and Lato river viruses). Thus, PoLV had properties somewhat intermediate between those of Tombusvirus and Carmovirus genera but bridged the two taxa through the serological relationship with some of their species. The taxonomic position of PoLV is still undetermined. It must await the results of molecular investigations now underway.

Maize Chlorotic Mottle Machlomovirus Expresses Its Coat Protein from a 1.47-kb Subgenomic RNA and Makes a 0.34-kb Subgenomic RNA

“…Both sgRNAs of tomato bushy stunt tombusvirus (TBSV) (Hillman et al, 1989), cymbidium ringspot tombusvirus (CyRSV) (Grieco et al, 1989), cucumber necrosis tombusvirus (CNV) (Rochon, et al, 1991), and artichoke mottle crinkle tombusvirus (Tavazza et al, 1994) have been mapped and have short untranslated leader regions 13-32 nt long. Although two sgRNAs were detected in pothos latent aureusvirus (Sabanadzovic et al, 1995) and cucumber leaf spot aureusvirus (Miller et al, 1997), only the transcription start site of the large sgRNA from cucumber leaf spot aureusvirus has been mapped to 30 nt upstream of the CP AUG. Dianthoviruses, the only genus with bipartite genomes, produce one sgRNA to express CP that is encoded on RNA1. The transcription start site of the sgRNA of red clover necrotic mosaic dianthovirus has been mapped to 62 nt upstream of the CP ORF (Zavriev et al, 1996).…”

Molecular characterization of a novel Aureusvirus infecting elderberry (Sambucus nigra L.)

“…The epidemiology of ElAV1 still remains unclear. Efforts at experimental transmission of ElAV1 to Nicotiana benthamiana and Chenopodium quinoa by mechanical inoculation have been unsuccessful so far, although the closely related Pothos latent virus is reported to be mechanically transmissible to these herbaceous hosts [ 1 , 5 , 12 ]. The evaluation of other transmission mechanisms typical for aureusviruses, by seeds or through the soil and/or soil-borne vector(s) is under progress.…”

Molecular analysis of the pothos latent virus genome.

“…PoLV was propagated in N. benthamiana. Virus purification and RNA extraction were as previously described (Sabanadzovic et al, 1995 ;. To obtain synthetic infectious transcripts of PoLV, a full-length cDNA copy of genomic RNA was cloned in two steps, downstream of the bacteriophage T7 RNA polymerase promoter.…”

“…Extracts were analysed for the presence of PoLV CP by SDS-PAGE and Western blotting. After transfer to Immobilon P nylon membranes (Millipore), the proteins were incubated with an antiserum raised against intact virus particles produced in rabbit (Sabanadzovic et al, 1995). The antigen-antibody complexes were detected by incubation with alkaline phosphatase-linked goat anti-rabbit IgG, followed by incubation with 5-bromo-4-chloro-3-indolyl phosphate (BCIP) and p-nitro blue tetrazolium (NBT) (Sigma).…”

“…Natural infection of other plants was not found (Sabanadzovic et al, 1995). Mechanical inoculation of PoLV to most herbaceous hosts results in chlorotic or necrotic spots on inoculated leaves 2-3 days post-inoculation (p.i.).…”