Arch Virol (1998) 143: 2189–2201
Nucleotide sequence of a resistance breaking mutant
of southern bean mosaic virus
L. Lee and E. J. Anderson
Department of Plant Pathology, University of Arkansas, Fayetteville, Arkansas, U.S.A.
Accepted June 16, 1998
Summary. SBMV-S is a resistance-breaking mutant of an Arkansas isolate of
the bean strain of southern bean mosaic virus (SBMV-B
) that is able to move
systemically in Phaseolus vulgaris cvs. Pinto and Great Northern, whereas the
causes local necrotic lesions and is restricted to the inoc-
ulated leaves of these hosts. Sequence analysis of the 4136 nucleotide genomes
and SBMV-S revealed seven nucleotide differences, but only
four deduced amino acid changes. A single amino acid change occurred in the
C-terminal region of the putative RNA-dependent RNA polymerase and three
differences were identiﬁed in the N-terminal portion of the virus coat protein.
and SBMV-S were compared with other sobemoviruses and were
found to contain a high level of nucleotide sequence identity (91.3%) to SBMV-
B. Unlike SBMV-B however, SBMV-B
and SBMV-S contained four putative
overlapping open reading frames, making them more similar in genome organiza-
tion to the cowpea strain, SBMV-C. The possibility exists that mutations or even
errors, that resulted in mis-identiﬁcation of open reading frames, occurred in pre-
viously published information on nucleotide sequence and genomic organization
The sobemovirus, southern bean mosaic virus (SBMV) causes mosaic and mottle
diseases in common bean (Phaseolus vulgaris L.) and cowpea (Vigna unguicu-
lata L. Walp.) [12, 27]. The virus is characterized by isometric particles (30 nm),
encapsidating a single-stranded positive-sense genomic RNA of approximately
The GenBank accession numbers of the sequences reported in this paper are SBMV-
: AF055887 and SBMV-S: AF055888.
Present address: Pioneer Hi-bred International, Inc., Johnston, Iowa, U.S.A.