Evidence for recombination among isolates of <Emphasis Type="Italic">Tobacco leaf curl Japan virus</Emphasis> and <Emphasis Type="Italic">Honeysuckle yellow vein mosaic virus</Emphasis>

Summary Complete nucleotide sequences of Tobacco leaf curl Japan virus (TbLCJV) isolates from infected tomato (Lycopersicon esculentum) plants in Nara (-[Jp2], 2764nt; -[Jp3], 2761nt), Kochi (-[Koc], 2760nt) and Yamaguchi (-[Yam], 2758nt) Prefectures, of Japan were determined. These sequences were compared with each other and the sequences of further begomoviruses from Japan. TbLCJV, TbLCJV-[Jp2], TbLCJV-[Jp3], TbLCJV-[Koc], TbLCJV-[Yam], Honeysuckle yellow vein mosaic virus (HYVMV), Eupatorium yellow vein virus (EpYVV), EpYVV-[MNS2], EpYVV-[SOJ3], EpYVV-[Yam] and EpYVV-[Tob] are monophyletic. The intergenic region (IR) of TbLCJV has highest nucleotide sequence identity with that of HYVMV (93%) whereas the rest of the genomic DNA had higher identity with that of TbLCJV-[Jp2] or -[Jp3] (91100%) than with that of HYVMV. In conclusion, TbLCJV has a chimeric genome which may have arisen by recombination between TbLCV-[Jp2] or -[Jp3]-like and HYVMV-like ancestors. Similarly, TbLCJV-[Yam] DNA has a hybrid genome, with a major parent HYVMV and minor parent TbLCJV-[Koc].     

A virus related to <Emphasis Type="Italic">Soybean mosaic virus</Emphasis> from <Emphasis Type="Italic">Pinellia ternata</Emphasis> in China and its comparison with local soybean SMV isolates

Summary. A potyvirus isolated from Pinellia ternata in China was characterised and shown to be related to Soybean mosaic virus (SMV). The virus was pathogenic on P. ternata and some soybean cultivars, whereas the local soybean SMV isolate HH5 did not infect P. ternata. Western blot experiments demonstrated a serological relationship between the virus from Pinellia, SMV and Watermelon mosaic virus (WMV). The complete nucleotide sequences of the Pinellia virus (isolate P-1, 9735nt) and of the Chinese soybean SMV isolates HH5 (9585nt) and HZ (9588nt) were determined. A 1733nt sequence at the 3-terminus of a second isolate from Pinellia (isolate P-2) was also determined. The predicted polyprotein of isolate P-1 has 83% amino acid (aa) identity with those of published SMV sequences. In many parts of the genome, aa identity was about 90% but it was much lower in the P1 protein region (24–29%), where it more closely resembled Dasheen mosaic virus (62%). The partial sequence of isolate P-2 had 91%nt identity to P-1 and both isolates resembled a recent sequence in the public databases (AF469171) wrongly named Zantedeschia mosaic virus. The two complete SMV soybean sequences had 93–95%nt identity with those of the previously sequenced isolates and >97% amino acid identity. Phylogenetic analysis and comparisons of coat proteins suggest that the Pinellia, WMV and SMV potyviruses should probably be treated as strains of the same species.     

Complete nucleotide sequence and genome organization of <Emphasis Type="Italic">Pelargonium flower break virus</Emphasis>

Summary. The complete nucleotide sequence of Pelargonium flower break virus (PFBV) has been determined. The genomic RNA is 3923 nucleotides (nt) long and contains five open reading frames (ORFs). The 5-proximal ORF encodes a 27kDa protein (p27) and terminates with an amber codon which may be read-through into an in-frame p56 ORF to generate a 86kDa protein (p86) containing the viral RNA dependent-RNA polymerase motifs. Two small ORFs, located in the central part of the viral genome, encode polypeptides of 7 (p7) and 12kDa (p12), respectively, which are very likely involved in virus movement. Interestingly, p12 presents a leucine zipper motif that has not been previously reported in related proteins. The 3-proximal ORF encodes a 37kDa capsid protein (CP). The p12 ORF is in-frame with the p86 ORF and a double read-through protein of 99kDa (p99) may be produced. Amino acid sequence comparisons revealed that the proteins encoded by ORFs 2, 3 and 4 are more similar to the corresponding gene products of Carnation mottle virus than to those of other carmoviruses, whereas the p27 and the CP show higher identity with the equivalent proteins of Saguaro cactus virus. Phylogenetic analysis conducted with the different viral products confirmed the assignment of PFBV to the genus Carmovirus.     

Molecular analysis of <Emphasis Type="Italic">Fiji disease virus</Emphasis> genome segments 5, 6, 8 and 10

Summary. The complete sequences of Fiji disease virus (FDV) genome segments 5 (S5), S6, S8 and S10 were obtained and comprised 3150nt, 2831nt, 1959nt and 1819nt, respectively. Each segment contained a single ORF which encoded putative proteins of 115kDa, 97kDa, 69kDa and 63.0kDa, respectively. The putative amino acid sequences encoded by S5 and S6 contained putative leucine zipper motifs while FDV S5 and S8 each contained an ATP-GTP-binding motif. At the amino acid level, FDV S5, S6, S8 and S10 showed most similarity to the corresponding segments of Rice black-streaked dwarf virus. Based on sequence similarities, it is predicted that FDV S8 encodes a minor core protein, while FDV S10 encodes an outer capsid protein. The evolutionary relationships of FDV to other reoviruses are discussed.The nucleotide sequence data for FDV S5, S6, S8 and S10 are available in the DDBJ/EMBL/GenBank databases under the accession numbers AY029521, AF356083, AY297693 and AY297694, respectively.     

In vitro activity of voriconazole and other antifungal agents against clinical isolates of <Emphasis Type="Italic">Candida glabrata</Emphasis> and <Emphasis Type="Italic">Candida krusei</Emphasis>

The antifungal susceptibility of 309 Candida glabrata and 63 Candida krusei clinical isolates was tested via the Sensititre YeastOne-3 system (Trek Diagnostic Systems, East Grinstead, UK) to compare the in vitro activity of voriconazole with that of five other antifungal agents (amphotericin B, fluconazole, itraconazole, ketoconazole, and flucytosine). Voriconazole was highly active (MIC90, 0.5 g/ml) against isolates of both species, including those for which the MICs of itraconazole and fluconazole were high (MIC90s of itraconazole, 2 g/ml for C. glabrata and 0.5 g/ml for C. krusei; MIC90s of fluconazole, 32 g/ml for C. glabrata and 64 g/ml for C. krusei). Ketoconazole MIC90 values for both species were identical to those of voriconazole. The MIC90 of amphotericin B was similar for both species (0.125 g/ml for C. glabrata and 0.25 g/ml for C. krusei). As expected, flucytosine was only moderately active against C. krusei isolates (MIC90, 16 g/ml) but was highly active against C. glabrata isolates (MIC90, 0.03 g/ml). Potential cross-resistance within the azole class was noted for some strains of C. glabrata (5.5%) that presented high MIC values for all the azoles tested. In order to consider voriconazole a viable alternative to other triazoles for the treatment of infections caused by Candida species, susceptibility testing of all clinically significant isolates of C. glabrata and C. krusei is recommended because of the potential for azole cross-resistance. The Sensititre YeastOne-3 seems to be a suitable commercial tool for this purpose.     

A minor outer capsid protein,P9, of <Emphasis Type="Italic">Rice dwarf virus</Emphasis>

Summary Partial amino acid sequence of a minor 30kDa polypeptide in purified Rice dwarf virus (RDV) was identical to the deduced amino acid sequence encoded by the dsRNA segment S9 of the virus. This polypeptide was specifically detected by Western blotting analysis with antibodies raised against the product of S9 expressed in a baculovirus system. Treatment of purified RDV particles with a relatively higher concentration of MgCl₂ removed the polypeptide from core particles together with other outer capsid proteins. These results demonstrate that the 30kDa polypeptide is a minor outer capsid protein that is encoded by genome segment S9 of RDV. This protein was named P9 protein.Received April 23, 2003; accepted May 23, 2003 Published online August 7, 2003     

Changes in level of virus accumulation and incidence of infection are critical in the characterization of <Emphasis Type="Italic">Rice tungro bacilliform virus</Emphasis> (RTBV) resistance in rice

Summary. Analysis by enzyme-linked immunosorbent assay showed that Rice tungro bacilliform virus (RTBV) accumulated in a cyclic pattern from early to late stages of infection in tungro-susceptible variety, Taichung Native 1 (TN1), and resistant variety, Balimau Putih, singly infected with RTBV or co-infected with RTBV+Rice tungro spherical virus (RTSV). These changes in virus accumulation resulted in differences in RTBV levels and incidence of infection. The virus levels were expressed relative to those of the susceptible variety and the incidence of infection was assessed at different weeks after inoculation. At a particular time point, RTBV levels in TN1 or Balimau Putih singly infected with RTBV were not significantly different from the virus level in plants co-infected with RTBV+RTSV. The relative RTBV levels in Balimau Putih either singly infected with RTBV or co-infected with RTBV+RTSV were significantly lower than those in TN1. The incidence of RTBV infection varied at different times in Balimau Putih but not in TN1, and to determine the actual infection, the number of plants that became infected at least once anytime during the 4wk observation period was considered. Considering the changes in RTBV accumulation, new parameters for analyzing RTBV resistance were established. Based on these parameters, Balimau Putih was characterized having resistance to virus accumulation although the actual incidence of infection was >75%.Received December 18, 2002; accepted March 19, 2003 Published online June 5, 2003     

Characterization of the small subgenomic RNA of <Emphasis Type="Italic">Soybean dwarf virus</Emphasis>

Summary. We have characterized a small subgenomic RNA of Japanese strains of Soybean dwarf virus (SbDV). Northern blot analyses of SbDV-infected plants showed that the small RNA contained the 3 terminal sequence of the genome and was detected in four typical Japanese SbDV strains, YS, YP, DS and DP. In the case of SbDV-DS, the RNA was 220 nucleotides in length and was transcribed from the 3 terminal region of the genome. This RNA appeared at a similar time to genomic RNA and a large sgRNA, and thereafter persisted in the infected plant. Since no conserved open reading frame (ORF) among the strains was postulated in the 3 terminal region, the small subgenomic RNA may have some regulatory roles in SbDV infections.Received December 12, 2002; accepted April 16, 2003 Published online July 2, 2003     

Complete nucleotide sequence and genome organization of a <Emphasis Type="Italic">Cactus virus X</Emphasis> strain from <Emphasis Type="Italic">Hylocereus undatus</Emphasis> (Cactaceae)

Summary. The complete nucleotide sequence of a strain of Cactus virus X (CVX-Hu) isolated from Hylocereus undatus (Cactaceae) has been determined. Excluding the poly(A) tail, the sequence is 6614 nucleotides in length and contains seven open reading frames (ORFs). The genome organization of CVX is similar to that of other potexviruses. ORF1 encodes the putative viral replicase with conserved methyltransferase, helicase, and polymerase motifs. Within ORF1, two other ORFs were located separately in the +2 reading frame, we call these ORF6 and ORF7. ORF2, 3, and 4, which form the triple gene block characteristic of the potexviruses, encode proteins with molecular mass of 25, 12, and 7KDa, respectively. ORF5 encodes the coat protein with an estimated molecular mass of 24KDa. Sequence analysis indicated that proteins encoded by ORF1-5 display certain degree of homology to the corresponding proteins of other potexviruses. Putative product of ORF6, however, shows no significant similarity to those of other potexviruses. Phylogenetic analyses based on the replicase (the methyltransferase, helicase, and polymerase domains) and coat protein demonstrated a closer relationship of CVX with Bamboo mosaic virus, Cassava common mosaic virus, Foxtail mosaic virus, Papaya mosaic virus, and Plantago asiatica mosaic virus.     

The complete nucleotide sequence of isolate BYMV-GDD of <Emphasis Type="Italic">Bean yellow mosaic virus</Emphasis>, and comparison to other potyviruses

Summary. The complete nucleotide sequence of Bean yellow mosaic virus (BYMV) gladiolus isolate GDD was determined and compared to broad bean isolates BYMV-MB4 and BYMV-S. The BYMV-GDD genome (9528nt) was more similar to BYMV-MB4 (9532nt) than to BYMV-S (9547nt), which has atypical symptom expression and host range. The greatest variability occurred in the 5 untranslated region, P1 protein, and NIa-VPg protein, the N-terminal two thirds of HC-Pro, and the C-terminal one third of P3. Each of these regions has been correlated with symptom or host differences between isolates of other potyviruses, and may contribute to the atypical nature of BYMV-S.     

Genetic variation among isolates of <Emphasis Type="Italic">White spot syndrome virus</Emphasis>

Summary. White spot syndrome virus (WSSV), member of a new virus family called Nimaviridae, is a major scourge in worldwide shrimp cultivation. Geographical isolates of WSSV identified so far are very similar in morphology and proteome, and show little difference in restriction fragment length polymorphism (RFLP) pattern. We have mapped the genomic differences between three completely sequenced WSSV isolates, originating from Thailand (WSSV-TH), China (WSSV-CN) and Taiwan (WSSV-TW). Alignment of the genomic sequences of these geographical isolates revealed an overall nucleotide identity of 99.32%. The major difference among the three isolates is a deletion of approximately 13kb (WSSV-TH) and 1kb (WSSV-CN), present in the same genomic region, relative to WSSV-TW. A second difference involves a genetically variable region of about 750bp. All other variations >2bp between the three isolates are located in repeat regions along the genome. Except for the homologous regions (hr1, hr3, hr8 and hr9), these variable repeat regions are almost exclusively located in ORFs, of which the genomic repeat regions in ORF75, ORF94 and ORF125 can be used for PCR based classification of WSSV isolates in epidemiological studies. Furthermore, the comparison identified highly invariable genomic loci, which may be used for reliable monitoring of WSSV infections and for shrimp health certification.     

Two unrelated double-stranded RNA molecule patterns in <Emphasis Type="Italic">Gremmeniella abietina</Emphasis> type A code for putative viruses of the families <Emphasis Type="Italic">Totiviridae</Emphasis> and <Emphasis Type="Italic">Partitiviridae</Emphasis>

Summary. Two double stranded (ds) RNA molecule patterns, probably of viral origin, were sequenced from Gremmeniella abietina var. abietina type A. The genome of Gremmeniella abietina RNA virus L1 (GaRV-L1) from isolate HR2 was 5133bp and contained two open reading frames (ORFs). The 5-proximal ORF coded for a putative coat protein (CP) and the 3-proximal ORF encoded putative RNA-dependent RNA polymerase (RdRp). GaRV-L1 had sequence similarities with a previously described totivirus (Helminthosporium victoriae 190S virus) and two unclassified members of family Totiviridae (Sphaeropsis sapinea RNA virus 1 and Sphaeropsis sapinea RNA virus 2). The genome of Gremmeniella abietina RNA virus MS1 (GaRV-MS1) from isolate C5 was composed of three dsRNA molecules coding for a putative RdRp (dsRNA1), a putative CP (dsRNA2) and protein of unknown function (dsRNA3). The lengths of these dsRNA molecules were 1782, 1586 and 1181bp, respectively. Sequence comparisons indicated that the GaRV-MS1 dsRNA pattern comprises a putative virus that is highly similar to Discula destructiva virus 1, Discula destructiva virus 2 and Fusarium solani virus 1 of the family Partitiviridae.     

Characterization of genotype II <Emphasis Type="Italic">Rubella virus</Emphasis> strains

Summary. Two genotypes of Rubella virus have been described that differ by 8–9% at the nucleotide level in the E1 glycoprotein gene. Of these, genotype II (RGII) was only recently reported and in this study two RGII viruses, the BRDII vaccine strain and BR1 wild type strain, were characterized. Monoclonal antibodies against each of the virion proteins (capsid [C], glycoproteins E1 and E2) and polyclonal anti-rubella virus sera reacted similarly with purified virions from the RGII and reference RGI strains on Western gels, with the exception of one anti-E2 Mab, and thus the two genotypes are closely related antigenically. The genomic sequences of two genotype II (RGII) rubella virus strains were determined and compared with the six previously reported RGI sequences. The genomes of these viruses all contained 9762nts and the lengths of the three untranslated regions (UTRs) and two open reading frames (ORFs) were identical. The overall difference between the RGI and RGII sequences at the nt level was 8% and this difference was maintained across most of the genome. At the amino acid level, the RGI and RGII sequences differed overall by 4%, however this difference was not uniform across the ORFs as the N-terminal third of P150 and the entirety of P90, both replicase proteins, were more conserved (<1% difference) while the C-terminal two thirds of P150 exhibited greater variation (8% difference), including a hypervariable region between residues 771–801 within which divergence as great as 20–30% was detected. The parent wt virus of the BRDII vaccine was not available and its sequence was compared with the BR1 sequence to identify potential attenuating mutations. The BRDII and BR1 sequences varied at 252 residues (2.59%), including twelve in the UTRs and thirty coding differences in the ORFs. None of these differences in the BRDII sequence was vaccine-specific when compared with RGI wt and vaccine sequences and, therefore, there appeared to be no common pathway in the generation of live, attenuated rubella vaccines.Current address: Respiratory and Enteric Viruses Branch, Division of Viral and Rickettsial Diseases, US Centers for Disease Control and Prevention, 1600 Clifton Rd., Atlanta, GA 30333, USAReceived January 2, 2003; accepted April 15, 2003 Published online July 2, 2003     

Nucleotide sequence of the coat protein genes of <Emphasis Type="Italic">Alstroemeria mosaic virus</Emphasis> and Amazon lily mosaic virus,a tentative species of genus <Emphasis Type="Italic">Potyvirus</Emphasis>

Summary. The nucleotide sequences of the 3 terminal region of the genomes of Alstroemeria mosaic virus (AlsMV) and the Amazon lily mosaic virus (ALiMV) have been determined. These sequences contain the complete coding region of the viral coat protein (CP) gene followed by a 3-untranslated region (3-UTR). AlsMV and ALiMV share 74.9% identity in the amino acid sequence of the CP, and 55.6% identity in the nucleotide sequence of the 3-UTR. Phylogenetic analysis of these CP genes and 3-UTRs in relation to those of 79 potyvirus species revealed that AlsMV and ALiMV should be assigned to the Potato virus Y (PVY) subgroup. AlsMV and ALiMV were concluded to have arisen independently within the PVY subgroup.     

Nucleotide sequence and genome organization of <Emphasis Type="Italic">Cucurbit yellow stunting disorder virus</Emphasis> RNA1

Summary. The complete nucleotide sequence of Cucurbit yellow stunting disorder virus (CYSDV) RNA1, a member of the Crinivirus genus in the Closteroviridae, was determined. CYSDV RNA1 is 9126 nucleotides long and contains two overlapping open reading frames (ORFs) that encode the replication module, consisting of the putative papain-like cysteine proteinase, methyl transferase, helicase, and polymerase domains, a small 5kDa hydrophobic protein and two further downstream ORFs potentially encoding proteins respectively 25 and 22kDa in size. The genomic position and homology of the four domains comprising the replication module appear to be similar for all sequenced criniviruses but there is divergence in the downstream ORFs, in terms of number, size, position and sequence homology.Received January 24, 2003; accepted May 14, 2003 Published online July 17, 2003     

<Emphasis Type="Italic">Sugarcane bacilliform virus</Emphasis> encapsidates genome concatamers and does not appear to integrate into the <Emphasis Type="Italic">Saccharum officinarum</Emphasis> genome

Summary. Sugarcane bacilliform virus (SCBV) DNA molecules larger than the complete genome length of 7.6kbp were detected in infected plants and in virions. We have confirmed that these high molecular weight nucleic acids were open circular DNA and viral in origin. Due to their open circular conformation, accurate size determination of the DNA molecules was not possible using conventional electrophoresis. Using field inversion gel electrophoresis (FIGE), however, the DNA appeared to increase in genome size increments, with sizes ranging from 1 to 4 genomes (31kbp) detected. The DNA was packaged into virions, which may explain the observation of purified virions with lengths corresponding to one, two or three times the modal length of 130nm. The DNA products were possibly concatamers formed during replication as a result of a terminal overlap on the sense strand, and were shown to be overlapped individual genome-length molecules and not covalently-bonded continuous DNA strands. Southern analysis indicated that SCBV sequences are not integrated into the sugarcane genome and that the high molecular weight DNA observed in the sugarcane accessions analysed represents SCBV concatamers.     

Strains of <Emphasis Type="Italic">Peru tomato virus</Emphasis> infecting cocona (<Emphasis Type="Italic">Solanum sessiliflorum</Emphasis>), tomato and pepper in Peru with reference to genome evolution in genus <Emphasis Type="Italic">Potyvirus</Emphasis>

Summary. Two isolates (SL1 and SL6) of Peru tomato virus (PTV, genus Potyvirus) were obtained from cocona plants (Solanum sessiliflorum) growing in Tingo María, the jungle of the Amazon basin in Peru. One PTV isolate (TM) was isolated from a tomato plant (Lycopersicon esculentum) growing in Huaral at the Peruvian coast. The three PTV isolates were readily transmissible by Myzus persicae. Isolate SL1, but not SL6, caused chlorotic lesions in inoculated leaves of Chenopodium amaranticolor and C. quinoa. Isolate TM differed from SL1 and SL6 in causing more severe mosaic symptoms in tomato, and vein necrosis in the leaves of cocona. Pepper cv. Avelar (Capsicum annuum) showed resistance to the PTV isolates SL1 and SL6 but not TM. The 5- and 3-proximal sequences of the three PTV isolates were cloned, sequenced and compared to the corresponding sequences of four PTV isolates from pepper, the only host from which PTV isolates have been previously characterised at the molecular level. Phylogenetic analyses on the P1 protein and coat protein amino acid sequences indicated, in accordance with the phenotypic data from indicator hosts, that the PTV isolates from cocona represented a distinguishable strain. In contrast, the PTV isolates from tomato and pepper were not grouped according to the host. Inclusion of the sequence data from the three PTV isolates of this study in a phylogenetic analysis with other PTV isolates and other potyviruses strengthen the membership of PTV in the so-called PVY subgroup of Potyvirus. This subgroup of closely related potyvirus species was also distinguishable from other potyviruses by their more uniform sizes of the protein-encoding regions within the polyprotein.The first two authors contributed equally.     

Determination of complete nucleotide sequence of <Emphasis Type="Italic">Hibiscus latent Singapore virus</Emphasis>: Evidence for the presence of an internal poly(A) tract

Summary. We have sequenced the complete genome of a hibiscus-infecting tobamovirus, Hibiscus latent Singapore virus (HLSV). The experimental host range of HLSV is similar to that of another distinct species of hibiscus infecting tobamovirus, Hibiscus latent Fort Pierce virus (HLFPV). The genomic structure of HLSV is similar to other tobamoviruses in general. It consists of a 5 untranslated region (UTR), followed by ORFs encoding for a 128kDa protein and a 186kDa readthrough protein, a 30kDa movement protein (MP), 18kDa coat protein (CP) and a 3 UTR. The unique feature of HLSV is the presence of a poly(A) tract within its 3 UTR. In our previous work, we have reported MP and CP sequences of HLSV and its phylogenetic analysis. Here we report the complete nucleotide sequence of HLSV, phylogenetic analysis of the nucleotide and amino acid sequences of 128/186kDa ORFs and the presence of a uniquely located poly(A) tract within the 3 UTR.The GenBank accession numbers of the sequences reported in this paper are AF400156, AF400157 and AY497578, respectively.     

The complete sequence of the genomic RNA of an isolate of <Emphasis Type="Italic">Lily virus X</Emphasis> (genus <Emphasis Type="Italic">Potexvirus</Emphasis>)

Summary. The complete sequence of the genomic RNA of an isolate of Lily virus X (LVX) has been determined for the first time. The isolate from the Netherlands was 5823 nucleotide (nt) long excluding the 3-poly(A) tail, making it the shortest reported potexvirus sequence. The 5-non-coding region begins with GGAAAA like that of Scallion virus X (ScaVX) and some isolates of Cymbidium mosaic virus (CymMV), whereas those of other sequenced potexviruses probably all begin with GAAAA. The genome organisation was similar to that of other members of the genus except that a TGBp3-like region lacked a normal AUG start codon. A phylogenetic analysis based on the entire coding sequence showed that LVX was most closely related to Strawberry mild yellow edge virus and belonged in a subgroup of the genus that also contains CymMV, Narcissus mosaic virus, ScaVX, Pepino mosaic virus, Potato aucuba mosaic virus and White clover mosaic virus.     

Complete nucleotide sequence of the RNA 1 of a grapevine isolate of <Emphasis Type="Italic">Arabis mosaic virus</Emphasis>

Summary. The complete nucleotide sequence of the genomic RNA 1 of the grapevine isolate NW (Neustadt an der Weinstrasse) of Arabis mosaic virus (ArMV) was determined. It is 7334 nucleotides long excluding the poly(A) tail, and contains one long open reading frame encoding a polypeptide of 2284 amino acids. The 5 and 3 non-coding regions were 227 and 252 nucleotides long respectively, and showed stretches of high identity with the corresponding 5 and 3 non-coding regions of ArMV-NW RNA 2. The analysis of the amino acid sequence of the polyprotein encoded by the RNA 1 of the ArMV-NW showed that the conserved amino acid motifs, characteristic for the viral protease co-factor, the NTP-binding protein, the cystein protease, and the RdRp core domains, were all present. Amino acid sequence comparisons between the polyproteins encoded by the RNAs 1 of ArMV-NW and other nepoviruses showed 75% identity with the GFLV-F13, and up to 36% with other nepoviruses.