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Plant Pathology 03/2009; 58(2):403 - 403. · 2.13 Impact Factor
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Plant Pathology 03/2007; 56(2):343 - 343. · 2.13 Impact Factor
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ABSTRACT: Leaf samples of Siegesbeckia glabrescens showing yellow vein, enation, and stunting symptoms were collected in Guangdong province, China. A specific 500-bp product was consistently detected in total DNA extracts, amplified with universal primers specific for members of the genus Begomovirus. Comparison of partial DNA sequences revealed that these virus isolates were identical, and therefore isolates GD13, GD24 and GD27 were selected for further sequence analysis. The complete nucleotide sequences of GD13, GD24 and GD27 were all found to be 2768 nucleotides (nts) long, with two open reading frames (ORFs) in the virion-sense strand and four ORFs in the complementary-sense strand, typical of the Old World begomoviruses. Sequence identities among the three isolates ranged from 99.7 to 99.8%. When compared with other reported sequences of begomoviruses, GD13 was most closely related to papaya leaf curl China virus (AJ876548), with a sequence identity of 76.8%. In addition, all isolates were found to be associated with DNAbeta molecules. The complete DNAbeta sequences of isolates GD13, GD24 and GD27 were determined. Sequence analysis showed that they had highest sequence identity with DNAbeta of Eupatorium yellow vein virus (AJ438938) (44.0, 43.9 and 45.6% identity). GD13, GD24 and GD27 are considered to be isolates of a distinct begomovirus species for which the name Siegesbeckia yellow vein virus (SgYVV) is proposed.
Archives of Virology 02/2007; 152(4):791-6. · 2.11 Impact Factor
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ABSTRACT: Two weed samples, G52 from Ageratum conyzoides and G87 from Malvastrum coromandelianum, showing leaf curling and vein thickening symptoms were collected in Nanning, Guangxi Province, China. The complete nucleotide sequences of DNA-A-like molecules of G52 and G87 were determined to be 2735 and 2745 nucleotides respectively. Both DNA-A molecules have a genomic organization typical of begomoviruses and share 73.4% sequence identity with each other. Sequence comparisons showed that the DNA-A of G52 and G87 were most closely related to those of Ageratum yellow vein virus (AYVV; 85% sequence identity) and Tobacco leaf curl Yunnanvirus (75.7% sequence identity) respectively. Further sequence comparisons showed that G52 has arisen by recombination among viruses related to AYVV, Papaya leaf curl China virus and an unidentified Begomovirus species. The molecular data suggest that G52 and G87 are two distinct begomoviruses, for which the names Ageratum leaf curl virus for G52 and Malvastrum leaf curl virus for G87 are proposed. The satellite DNAβ molecule was only found to be associated with G87. G87 DNAβ consists of 1354 nucleotides, and shares the highest nucleotide sequence identity (68.9%) with that associated with Sida yellow vein China virus. A defective DNAβ molecule was also found to be associated with G87.
Journal of Phytopathology 11/2006; 154(11‐12):648 - 653. · 0.79 Impact Factor
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Plant Pathology 03/2006; 55(2):291 - 291. · 2.13 Impact Factor
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ABSTRACT: Three begomovirus isolates, G46, G83 and G84 from Senecio scandens showing yellow mosaic symptoms were collected from Guangxi Province, P.R. China. The isolates were detected by PCR using universal primers for begomoviruses. Comparison of partial DNA-A sequences (approximately 500 bp) of the isolates revealed their 98.7-99.1% identity. The isolate G46, chosen for complete DNA-A sequencing, consisted of 2746 nt and had a typical genomic organization of begomoviruses. The G46 DNA-A had the highest sequence identity (72.4%) with that of Ageratum leaf curl virus among begomoviruses. The molecular data suggest that the isolate G46 is a new begomovirus (species), for which the name Senecio yellow mosaic virus (Senecio yellow mosaic virus) is proposed.
Acta virologica 02/2005; 49(3):211-5. · 0.68 Impact Factor
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Plant Pathology 12/2004; 53(6):799 - 799. · 2.13 Impact Factor
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ABSTRACT: Tobacco leaf curl Yunnan virus (TbLCYNV) isolates Y136 and Y143 were both shown to contain DNAβ molecules. Seven DNAβ molecules, each consisting of 1334–1341 nucleotides, were cloned and characterized. Sequence comparison showed that they were of two main types: type 1 included five DNAβ molecules with 75–99% overall nucleotide sequence identity, and type 2 included two DNAβ molecules with >99% overall nucleotide sequence identity. Only 52–54% nucleotide identity was found between the two types of DNAβ molecules. The two isolates were associated with both types of DNAβ. A relationship dendrogram analysis showed that type 1 DNAβ molecules clustered with the DNAβ molecules of Tomato yellow leaf curl China virus, whereas type 2 DNAβ molecules clustered with the DNAβ of Tomato yellow leaf curl Thailand virus. Evidence was also provided that type 2 DNAβ molecules may have arisen by recombination between the DNAβ of Tobacco curly shoot virus and another unidentified virus. To date, only a single type of DNAβ molecule had been found to be associated with one begomovirus. The possible reasons of TbLCYNV associated with two types of DNAβ molecules are discussed.
Journal of Phytopathology 12/2004; 152(11‐12):647 - 650. · 0.79 Impact Factor
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ABSTRACT: The importance of diseases of tomato caused by begomoviruses is increasing worldwide. Here, we report that several begomoviruses are associated with tomato leaf curl disease in Yunnan province, China. 14 tomato samples showing leaf curl symptoms were collected in three districts in Yunnan, and they fell into four groups according to their reaction with a panel of 16 monoclonal antibodies in TAS-ELISA. Comparison of partial DNA-A sequences amplified with degenerate primers confirmed the existence of several types of begomoviruses. The complete DNA-A sequences of 4 isolates (Y25, Y41, Y72, Y161), corresponding to the four groups, were determined. Sequence comparisons and phylogenetic analysis revealed that they corresponded to four previously identified begomoviruses. Groups I, II and IV are most closely related to Tomato yellow leaf curl China virus (TYLCCNV), Tobacco curly shoot virus (TbCSV) and Tobacco leaf curl Yunnan virus (TbLCYNV), respectively, while Group III shows close relationships with Tomato yellow leaf curl Thailand virus (TYLCTHV). In addition, all isolates in Groups I and III were found to be associated with DNAbeta molecules, while satellite DNA was not found in virus isolates in Groups II and IV. The complete DNAbeta sequences of three isolates from Group III (Y72, Y77, Y79) were determined. Sequence analysis showed that Y72beta, Y77beta and Y79beta seem to be different from other characterised DNAbeta, sharing the highest nucleotide sequence identity with DNAbeta of TbCSV.
Archives of Virology 10/2004; 149(9):1721-32. · 2.11 Impact Factor
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ABSTRACT: Virus isolate G35 was obtained from Euphorbia pulcherrima showing leaf curl and vein thickening symptoms in Tianyang, Guangxi Province, China. The virus was transmitted by whiteflies to Nicotiana tabacum, Lycopersicon esculentum, Datura stramonium and E. pulcherrima. DNA-A contains 2746 nucleotides, with two open reading frames (ORFs) in the virion-sense DNA and four ORFs in the complementary-sense DNA. When compared with the DNA-A sequence of other begomoviruses, the total DNA-A of isolate G35 was most closely related to that of Ageratum enation virus (79.9% sequence identity). However, the deduced coat protein of G35 is most like that of Pepper leaf curl virus from Bangladesh (94.9% amino acid sequence identity), and the AC1 of G35 is most like that of Cotton leaf curl Multan virus-Okra (87.2% amino acid sequence identity). The molecular data showed that G35 is a distinct Begomovirus species, for which the name Euphorbia leaf curl virus (ELCV) is proposed.
Journal of Phytopathology 04/2004; 152(4):215 - 218. · 0.79 Impact Factor
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ABSTRACT: Virus isolate Y23V, obtained from squash showing leaf curl symptoms in Yunnan, China, was readily differentiated from four studied Chinese begomovirus isolates in reactions with a set of monoclonal antibodies raised against begomoviruses. The complete nucleotide sequence (2714 nts) of the DNA-A-like molecule of Y23V was determined. The DNA-A of Y23V is most closely related to that of tomato yellow leaf curl Thailand virus-[1] (TYLCTHV-[1]) (84% sequence identity). However, the AC1 and AC4 gene of Y23V DNA-A resembled to Pepper leaf curl virus from Bangladesh (PepLCBDV). The DNA-A of Y23V has three distinct regions: the region from 74-2071 nts is 95% identical to TYLCTHV-[1] excluding a 27 nt deletion; the following 386 nts are 91% identical to PepLCBDV and the rest of the DNA-A is not closely related to any reported begomovirus. Y23V, therefore, is considered to have arisen by recombination. The 84% sequence identity of Y23V with TYLCTHV-[1] allows Y23V to be considered as a distinct begomovirus species, for which the name squash leaf curl Yunnan virus (SLCYNV) is proposed.
Archives of Virology 11/2003; 148(10):2047-54. · 2.11 Impact Factor
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ABSTRACT: Three monoclonal antibodies (MAbs) were raised against the virion protein of Sugarcane mosaic virus Zhejiang isolate (SCMV-ZJ). All three MAbs, which belong to the immunoglobulin (IgG1) subclass, reacted with isolates of SCMV but not with seven other viruses tested by indirect antigen-coating plate enzyme-linked immunosorbent assay (ELISA) (ACP-ELISA). MAb 2B5 was used in indirect ACP-ELISA for the detection of SCMV in maize leaf samples showing dwarf mosaic symptoms, and all 176 were found to be infected. Results of ACP-ELISA with MAb 2B5 correlated well with those obtained by reverse transcriptase-polymerase chain reaction (RT-PCR) using the same tissues. This demonstrates that MAb 2B5 can be used to detect isolates of SCMV in field samples and that the virus is possibly the most common cause of maize dwarf mosaic disease in different parts of China.
Journal of Phytopathology 06/2003; 151(6):361 - 364. · 0.79 Impact Factor
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ABSTRACT: Sugarcane mosaic virus (SCMV) was detected in all 62 maize samples collected from eight maize-growing provinces in China showing dwarf mosaic symptoms by immunocapture reverse-transcription polymerase chain reaction (RT-PCR). Maize dwarf mosaic virus (MDMV), Sorghum mosaic virus (SrMV) and Johnsongrass mosaic virus (JGMV), however, were not detected in any of the samples by RT-PCR. Eleven cDNA fragments of approximately 0.8 kilobases covering most of the coat protein (CP) gene of SCMV were sequenced and sequence analysis indicates that these eleven isolates share 98.1 to 100 % identity at the amino acid level. Sequence comparison and phylogenetic analysis of the CP genes from the eleven Chinese isolates as well as 21 SCMV subgroup virus isolates indicate that the eleven Chinese virus isolates were closely related to SCMV with 97.0 to 98.1 % sequence identity at the amino acid level, while relatively lower sequence identity was found with MDWV, SrMV or JGMV. The results indicate that the Chinese isolates are members of the SCMV species, and thus, SCMV can be considered as the most common and important potyvirus infecting maize in China.
Archives of Virology 01/2003; 147(12):2437-43. · 2.11 Impact Factor
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ABSTRACT: The VP37 protein encoded by the RNA2 of Broad bean wilt virus 2 (BBWV2) was overexpressed in Escherichia coli. The protein was purified and a polyclonal antibody specific for the protein was produced. Time course studies by Western blot assays in BBWV2-infected Chenopodium quinoa leaves showed that the VP37 protein was present in cells of the inoculated leaves by 12 h post inoculation and in cells of systemically-infected leaves by 2 days post inoculation. The protein was able to accumulate to a high level in infected leaves at the late infection stage. Gel retardation and UV cross-linking assays demonstrated that the VP37 protein bound preferentially single-stranded (ss) RNA and DNA in a non-sequence-specific manner. The VP37 protein-RNA complex was stable in solutions containing less than 400 mM NaCl, but became fully dissociated in the solutions containing 800 mM NaCl. Sequence analysis of the VP37 protein and its ability to bind ssRNA and ssDNA suggest that the protein may play a role similar to the movement proteins reported for other plant viruses.
Archives of Virology 06/2002; 147(5):917-28. · 2.11 Impact Factor
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ABSTRACT: Virus isolate Y3V, obtained from tobacco showing leaf curl symptoms in Yunnan, China, had particles with the size and morphology typical of geminiviruses. In reactions with a set of monoclonal antibodies raised against begomoviruses, Y3V was readily differentiated from two previously studied Chinese Begomovirus isolates. The complete nucleotide sequence of a DNA-A-like molecule of Y3V was determined; it comprises 2744 nucleotides and has a typical Begomovirus genome organization. When compared with the DNA-A sequences of other begomoviruses, the total DNA-A of Y3V was most closely related to that of Ageratum yellow vein virus (AYVV) (85% sequence identity), but the Y3V intergenic region differed greatly from those of the other sequences (maximum 70% identity). In contrast, the deduced coat protein of Y3V is most like that of Tomato yellow leaf curl Thailand virus-[1] (TYLCTHV-[1]) (92% amino acid sequence identity). The molecular data show that the Yunnan isolate of Tobacco leaf curl virus is a distinct Begomovirus species, for which the name Tobacco leaf curl Yunnan virus (TLCYnV) is proposed.
Archives of Virology 09/2001; 146(8):1599-606. · 2.11 Impact Factor
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ABSTRACT: Defective DNA of tobacco leaf curl virus (TLCV) was identified in TLCV-infected tobacco plants. The defective DNA was cloned and sequenced. The sequence showed it was about half the size of the TLCV DNA-A, and was derived from TLCV DNA-A by a large deletion. The defective DNA contained the intergenic region and part of the AC1 (Rep) gene of TLCV, and also novel open reading frames (ORFs). The immunotrapping tests showed the defective DNA was associated with geminate particles, suggesting it could be encapsidated in virus particles. It was transmitted, along with full-length DNA-A, to tobacco plants by grafting and whitefly (Bemisia tabaci).
Acta virologica 03/2001; 45(1):45-50. · 0.68 Impact Factor
