The complete genome sequence of alfalfa dwarf virus, a new putative cytorhabdovirus

BEJERMAN NICOLAS; GIOLITTI, FABIÁN; DE BREUIL SOLEDAD; TRUCCO VERONICA; LENARDON, SERGIO; DIETZGEN RALF

Montreal

Congreso; XVI International Congress of Virology; 2014

Alfalfadwarf virus (ADV) was detected in lucerne (alfalfa) crops distributedthroughout Argentina. Diseased plants had shortened internodes, a bushyappearance, deformations, puckering, epinasty of leaflet blades, vein enations,and varying sized papillae on the adaxial leaflet surfaces. The full-length nucleotide sequence of thegenomic RNA of ADV was obtained using a combination of deep sequencingof small RNAs and Sanger sequencing of PCR-amplified fragments. ADV genome comprised 14,491 nucleotides andthe analysis of the antigenomic sequence of the negative-sense viral RNA genomerevealed seven open reading frames (ORFs). Each of the ORFs found, except that encodingthe polymerase gene, was amplified and sequenced to confirm the results of the in silico analysis of the sequence. Thegenome organization of ADV was similar to that of strawberry crinkle virus(SCV), a member of the genus Cytorhabdovirus:3?-N-P-P3-M-G-P6-L-5?, where N is the nucleocapsid protein gene, P theputative phosphoprotein gene, 3 and 6 are genes coding for proteins of unknownfunction, M the putative matrix protein gene, G the glycoprotein gene, and Lthe putative polymerase gene. ADVformed a distinct cluster with viruses in the genus Cytorhabdovirus: persimmonvirus A (PeVA), lettucenecrotic yellows virus and lettuce yellow mottle virus ina phylogenetic tree based on the N protein sequence, which confirmed previousresults based on alignments of a partial fragment of the L gene. Furthermore, aminoacid sequence comparisons with the corresponding sequences of other rhabdovirusesrevealed the closest relationship to PeVA (genome sequence of SCV is notpublically available), with identities ranging from 17.4% for the matrixproteins and 43.1% for the L proteins. These results indicate that ADV may be classifiedas a new species in the genus Cytorhabdovirus.