Arch Virol (1999) 144: 1587–1600
Molecular characterization of an atypical Old World
strain of Peanut stunt virus
M. R. Hajimorad
, C.-C Hu
, and S. A. Ghabrial
Department of Plant Pathology, University of Kentucky, Lexington, Kentucky, U.S.A.
Accepted March 15, 1999
Summary. Northern blot analyses of RNAs from an Iranian strain of Peanut stunt
virus (PSV-ICucumovirus)using cloned cDNA probes to the genomic RNAsfrom
two PSV strains, PSV-ER (subgroup I) and PSV-W (subgroup II), indicated that
PSV-I RNA-3 is derived from a subgroup II strain. No hybridization signals, how-
ever, were detected with PSV-I RNAs 1 and 2 suggesting they are distinct from
both subgroups I and II. Nucleotide (nt) sequence analysis of cloned cDNA frag-
ments (1–1.5 kbp in size) representing PSV-I RNAs 1 and 2 showed that PSV-I
is more closely related to subgroup II strains than to any other sequenced cu-
cumovirus. The percent nt identity between RNA-1 sequences from PSV-I and
PSV-ER or between PSV-I and PSV-W were 79.1% and 88.8%, respectively. The
corresponding values for RNA-2 were 77.5% and 86.7%. Sequence comparison
analyses of deduced amino acid sequence of cloned partial sequences of PSV-I
RNAs 1 and 2 indicated that PSV-I 1a and 2a proteins are most closely related to
those of subgroup II strains (93% identity). PSV-I supported the replication and
encapsidation of PSV G-satellite RNA (G-satRNA), but not cucumber mosaic
virus WL1-satRNA. PSV-I may be perceived as an Old World derivative of sub-
group II strains, or it may represent a natural reassortment between a subgroup II
(RNA-3) and an as yet uncharacterized subgroup of PSV strains (RNAs 1 and 2).
Peanut stunt virus (PSV) is a member of the genus Cucumovirus in the family
Bromoviridae . Other members of the genus are Tomato aspermy virus (TAV)
The nucleotide sequence data reported in this paper have been deposited in the GenBank
under accession numbers AF083498 (PSV-I RNA-1) and AF083499 (PSV-I RNA-2).
Department of Plant Pathology, Iowa State University, Ames, IA
Agricultural Biotechnology Laboratories, National Chung-Hsing Univer-
sity, Taichung 402, Taiwan.