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

Abstract

The interactions of seven isolates of peanut stunt cucumovirus (PSV) originating from North America, Europe and Africa, and two variants of PSV satellite RNA (sat RNA) were analysed. Electrophoretic and immunoblot analyses of the coat protein (CP) and Northern blot hybridization analyses of the viral RNAs showed that isolates PSV F352, 1339 and 1507 belonged to subgroup I, and isolates PSV W, Su and B to subgroup II. The seventh isolate, robinia mosaic virus (RoMV) clustered with subgroup I isolates by CP analysis, but was related to both subgroups by RNA hybridization analysis. The ability to support the accumulation of two newly described sat RNA variants, P4 and P6 sat RNAs, was not

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

“…Another taxonomically uncertain PSV isolate is PSV-Ro, originally named Robinia mosaic virus. Recently PSV-Ro was placed with in PSV subgroup I, based on Western blot analysis, but it could not be classified within either subgroup based on Northern hybridization results [11]. These results indicate that within the Cucumovirus genus, PSV is genetically the most diverse, followed by CMV, whereas TAV is least variable.…”

“…PSV-E and W in subgroups I and II were first reported in the United States. At present, strains of both of these subgroups have been reported worldwide [11,21]. PSV widely occurs in the peanut growing areas in Northern China, including the Shandong, Hebei, Henan and Jiangsu provinces [22].…”

Production of infectious RNA transcripts from full-length cDNA clones representing two subgroups of peanut stunt virus strains: mapping satellite RNA support to RNA1.

“…Results of computer-assisted protein secondary structure prediction, using the GOR algorithm (as used by Roossinck et al, 1997), revealed that a 13 aa α-helix at the Cterminal region of the 1a proteins from subgroup I strains PSV-ER and PSV-J was shortened to 7 aa followed downstream by a 4 aa β-sheet region in the two subgroup II strains, PSV-W and PSV-B (data not shown). These differences in secondary structures apparently have no bearing on support of satRNA replication, since the predicted secondary structure of the 1a protein from PSV-B, a subgroup II strain that supports satRNA replication (Milita4 o et al, 1998), is identical to that of PSV-W. Thus the proposal that changes in the secondary structure of the C-terminal region of the 1a protein are responsible for the loss in ability to replicate satRNA may not be applicable to PSV satRNA.…”

“…We have recently cloned and sequenced RNA1 from strain PSV-B which belongs to subgroup II of PSV strains (C.-C. Hu and others, unpublished data). Because PSV-B is closely related to PSV-W (about 95 % nt sequence identity) and, unlike PSV-W, is capable of replicating satRNA (Milita4 o et al, 1998), it should provide valuable material for mutational and molecular genetic analysis to map the RNA1 sequences required for satRNA replication.…”

3′-End Stem-Loops of the Subviral RNAs Associated with Turnip Crinkle Virus Are Involved in Symptom Modulation and Coat Protein Binding

“…It was suggested that the hairpin forms a tertiary structure with a distantly located bulged loop which then interacts with putative host and/or viral components, leading to the suppression of viral symptoms (28). However, there is yet no evidence for host involvement (5,23).…”