The Complete Nucleotide Sequence of a Japanese Isolate of White clover mosaic virus Strain RC

The complete nucleotide sequence was determined for genomic RNA of White clover mosaic virus (WClMV-RC) isolated from red clover (Trifolium pratense) in Japan, It is 5843 nucleotides in length, excluding the poly(A) tail at the 3' terminus. Similar to other potexviruses, it contains five open reading frames (ORFs 1 through 5), which putatively encode an RNA-dependent RNA polymerase (RdRp) (147 kDa), a triple gene block (TGB) (26 kDa/13 kDa/7 kDa), and a coat protein (CP) (22 kDa), respectively. The deduced amino acid sequence of the WClMV-RC CP was identical to that of WClMV-O, one of two New Zealand isolates, but only 85% identical to that of WClMV-M, the other New Zealand isolate, because of heterogeneity in the C-termini of CP amino acid sequences. The implication of this CP heterogeneity is discussed. Received 30 August 2001/ Accepted in revised form 11 January 2002     

Nandina mosaic virus is an isolate of <Emphasis Type="Italic">Plantago asiatica mosaic virus</Emphasis>

The complete nucleotide sequence of the genome of Nandina mosaic virus (NaMV), which has tentatively been assigned to the genus Potexvirus, is reported. The sequence is 6066 nt in length, excluding the poly(A) tail, and contains ORFs coding for proteins of 155, 25, 12, 13, and 21 kDa (ORFs 1–4 and the CP), respectively. The genomic organization of the virus and the signature motifs in the putative protein products are similar to the data reported for potexviruses for which complete sequences are known. Phylogenetic comparisons indicated that NaMV is most closely related to Plantago asiatica mosaic virus (PlAMV). Pairwise comparisons of the sequence data for these two viruses indicate that, based on criteria recently proposed for genera within the family Flexiviridae, NaMV and PlAMV should be considered to be strains/isolates of the same viral species. Both NaMV and PlAMV were first reported in 1976 but, as PlAMV was sequenced first, this name should take precedence with the name NaMV being relegated to a synonym.     

Pepino mosaic virus isolates and differential symptomatology in tomato

Based on a survey conducted in commercial tomato production in Belgium in 2006, four Pepino mosaic virus (PepMV) isolates that differed in symptom expression in the crop of origin were selected for greenhouse trials. The selected isolates were inoculated onto tomato plants grown in four separate plastic tunnels. PepMV symptom development was assessed regularly and extensive sampling followed by ELISA analyses, genotyping and sequencing was performed to study viral presence and variation in PepMV sequences throughout the trial period. Two isolates (EU-mild and CH2-mild) that were selected based on mild symptom expression in the crop of origin caused only mild symptoms in the trial, while two other isolates (CH2-aggressive and EU + CH2) that were selected for severe symptom display, caused considerably more severe symptoms. Sequence homology between CH2-mild and CH2-aggressive was as high as 99·4%. Results of this study show that differential symptom expression can, at least partially, be attributed to the PepMV isolate, which may be related to minor differences at the nucleotide level between isolates.     

一种侵染滇重楼的Potexvirus病毒分离物分子鉴定及其3'末端序列分析

 从云南武定的滇重楼上得到一个病毒分离物Paris-YN,病毒粒体为弯曲线状。利用RT-PCR扩增获得一条1074bp的片段,序列比较分析发现其与马铃薯X病毒属(Potexvirus)病毒3'末端的结构最为相似,且与属内的白三叶草花叶病毒等20个不同分离物3'末端有36.7%~58.9%的同源性;该病毒cp基因长639个核苷酸,编码212个氨基酸(22.8kDa),与20个Potexvirus病毒分离物的CP氨基酸序列比较发现,Paris-YN与白三叶草花叶病毒的CP氨基酸同源性最高(60.1%)。证据表明,该分离物可能为Potexvirus的新成员,暂命名为重楼X病毒(Paris polyphylla virus X)。     

The Complete Nucleotide Sequence of Potato virus X Strain OS: The First Complete Sequence of a Japanese Isolate

The complete nucleotide sequence of the genomic RNA of a Japanese isolate of Potato virus X (PVX), strain OS (PVX-OS), was determined. The PVX-OS genome is 6435 nucleotides in length, excluding the 3′ poly(A) sequence, and encodes for five open reading frames (ORFs), similar to other reported PVX strains. Comparisons of the nucleotide sequence of PVX-OS with those of European and South American PVX strains revealed that the PVX-OS genomic sequence showed 95-96% homology with European strains and 77-78% with South American strains. Phylogenetic analysis of PVX-OS and other PVX strains found that PVX-OS clusters with European strains. This is the first report on the complete nucleotide sequence of a PVX strain from Japan. Received 10 May 2001/ Accepted in revised form 26 October 2001