Evidence for the occurrence of two distinct subgroups of peanut stunt cucumovirus strains: molecular characterization of RNA3.

Abstract

Strains of peanut stunt cucumovirus (PSV) were classified into two distinct subgroups, I and II, based on Western and Northern blot analyses using antisera and cloned cDNA probes to strains PSV-ER and PSV-W. These results were corroborated by nucleotide sequence analyses of full-length cDNA clones of RNA3 from representative strains of the two subgroups. Whereas the percentage nucleotide sequence identity between PSV-ER (or PSV-J) and PSV-W RNA3s was determined to be 80 %, the corresponding value between strains ER and J was 91 %, confirming that strains ER and J belong to the same subgroup (subgroup I) whereas strain W belongs to a separate subgroup (subgroup II). PSV-W and PSV-ER RNA3s are 2173 and 2188 nucleotides long, respectively. Each is dicistronic,

Nucleotide sequence analyses of genomic RNAs of Peanut stunt virus Mi, the type strain representative of a novel PSV subgroup from China

“…The complete nucleotide sequence of the RNAs of PSV-J was first reported by Karasawa et al in 1992 [7, 8]. Hu and colleagues classified PSV strains into two distinct subgroups based on the RNA sequence of RNA3: subgroup I containing PSV-ER and related strains and subgroup II containing PSV-W [6].…”

“…ORF3a (nt 117-980 of RNA3) encompasses 864 nt and encodes the movement protein with a calculated M r of 30,942. The deduced aa sequence of this protein contains the conserved motif MSVPQVLCAITRTVTAEAEGSIRIYLADLGDNE typical of the 30 K movement protein superfamily [14]; within this 33 aa conserved region, PSV strains exhibit eight variable residues compared to only one variable residue among CMV strains [6]. PSV-Mi ORF3b (nt 1229-1882 of RNA3) encodes the viral coat protein with a calculated M r of 23,643.…”

Differential interactions among isolates of peanut stunt cucumovirus and its satellite RNA.

“…Thus, hybridization analyses confirm that PSV isolates F352, 1339 and 1507 and isolates B, Su and W form two welldefined groups corresponding to the subgroups I and II defined by Hu et al (1997). RoMV which, according to CP analysis, could be grouped into subgroup I, does not belong clearly to only one of these two subgroups and is partially related to both.…”

“…azRuiz & Kaper, 1983 ;Xu et al, 1986 ;Naidu et al, 1995 ;Hu et al, 1997). Subgroup I was exemplified by isolates from the Eastern (E) serotype, and subgroup II by isolates of the Western (W) serotype (Mink et al, 1969).…”

“…Classification of PSV strains into two subgroups was further supported by competition hybridization analyses (Dı! az-Ruiz & Kaper, 1983) and, recently, by nucleotide sequence analysis of RNA 3, which showed identities of above 90 % for subgroup I (E-type) strains and of about 80 % between subgroup I and subgroup II (W-type) strains (Hu et al, 1997). Nevertheless, serology comparisons involving primarily Old World isolates suggest a higher diversity for PSV, as there are strains that do not fit clearly into types E (subgroup I) or W (subgroup II) (Richter et al, 1987).…”