F. Moonan et al., Sugarcane yellow leaf virus: An emerging virus that has evolved by recombination between luteoviral and poleroviral ancestors, VIROLOGY, 269(1), 2000, pp. 156-171
We have derived the genomic nucleotide sequence of an emerging virus, the S
ugarcane yellow leaf virus (ScYLV), and shown that it produces one to two s
ubgenomic RNAs. The family Luteoviridae currently includes the Luteovirus,
Polerovirus, and Enamovirus genera. With the new ScYLV nucleotide sequence
and existing Luteoviridae sequence information, we have utilized new phylog
enetic and evolutionary methodologies to identify homologous regions of Lut
eoviridae genomes, which have statistically significant altered nucleotide
substitution ratios and have produced a reconstructed phylogeny of the Lute
oviridae. The data indicate that Pea enation mosaic virus-1 (PEMV-1), Soybe
an dwarf virus (SbDV), and ScYLV exhibit spatial phylogenetic variation (SP
V) consistent with recombination events that have occurred between polerovi
ral and luteoviral ancestors, after the divergence of these two progenitor
groups. The reconstructed phylogeny confirms a contention that a continuum
in the derived sequence evolution of the Luteoviridae has been established
by intrafamilial as well as extrafamilial RNA recombination and expands the
database of recombinant Luteoviridae genomes that are currently needed to
resolve better defined means for generic discrimination in the Luteoviridae
(D'Arcy, C. J. and Mayo, M. 1997. Arch. Virol. 142, 1285-1287). The analys
es of the nucleotide substitution ratios from a nucleotide alignment of Lut
eoviridae genomes substantiates the hypothesis that hot spats for RNA recom
bination in this virus family are associated with the known sites for the t
ranscription of subgenomic RNAs (Miller et al. 1995. Crit Rev. Plant Sci. 1
4, 179-211), and provides new information that might be utilized to better
design more effective means to generate transgene-mediated host resistance.
(C) 2000 Academic Press.