First Report of Turnip mosaic virus in Rhubarb in Alaska

In July 2003, noticeable red lesions were observed on rhubarb leaves (Rheum rhababarum cv. Kerwin) from a plant at the Arctic Plant Germplasm Research and Introduction Project in Palmer, AK. Extracts of leaf tissue tested positive for a potyvirus using indirect enzyme-linked immunosorbent assay (ELISA) and western blots with a monoclonal antibody specific to the potyvirus group (Agdia, Inc., Elkhart, IN). During the following growing season (June 2004), obvious chlorotic ringspots developed into red lesions on the same plant and an adjacent plant of the same cultivar. Partially purified particles that were isolated from the infected rhubarb plants were mechanically inoculated to an experimental host range (number of infected plants per total number of plants), resulting in lesions on leaves of Rheum palmatum (1 of 2) and Chenopodium amaranticolor (3 of 5) but none on C. quinoa (0 of 4). The leaves with local lesions from C. amaranticolor were ground in phosphate buffer (1 g of tissue per 10 ml of buffer), and the extract rubbed onto a set of plants resulting in lesions on R. hybridum (raponticum) (1 of 2), C. amaranticolor (1 of 4), and C. quinoa (1 of 4). The original diseased rhubarb plants and experimental symptomatic plants were confirmed to have a potyvirus using ELISA. Subsequent compound direct ELISA and western blot assays revealed that the virus reacted strongly to monoclonal or polyclonal antibodies to Turnip mosaic virus (TuMV) (Agdia, Inc.). Total RNA was extracted from leaves of the naturally infected rhubarb plants with an RNeasy Plant Mini Kit (Qiagen Sciences, Germantown, Maryland), and used in reverse-transcription-polymerase chain reaction (RT-PCR) with specific primers for TuMV (1) predicted to amplify a 1,134-bp 3′-terminal cDNA fragment encompassing the 3′-end of the nuclear inclusion protein gene (NIb), the coat protein gene, and the 3′-nontranslated region. A PCR product of approximately the expected size was obtained and then sequenced. Sequences (1,077 nt) that corresponded to the TuMV coat protein gene and 3′-terminal noncoding region were submitted to Genbank (Accession No. AY744930). Blast searches against NCBI (National Center for Biotechnology Information) contained high identities to many TuMV isolates with up to 96% (1,043 of 1,077) nucleotide identity (i.e., GenBank Accession No. AF169561). Similar high identities of up to 97% at the amino acid level occurred within the coat protein coding region (i.e., GenBank Accession No. BAC02892.1). Infected rhubarb plants were removed from the site and none of the remaining 109 plants tested positive for TuMV using ELISA. On the basis of the mechanical transmission to plant hosts, the definitive TuMV serology, and the consensus of sequenced regions with TuMV, we concluded that the causal agent of the diseased rhubarb plants was TuMV. Although TuMV has a wide plant host range occurring worldwide (2), to our knowledge, this is the first report of TuMV in rhubarb in Alaska and the first time that TuMV has been detected in Alaska. References: (1) P. Lehmann et al. Physiol. Mol. Plant Pathol. 51:195, 1997. (2) R. Provvidenti. Page 1340 in: Viruses of Plants. A. A. Brunt et al., eds. CAB International, Wallingford, UK, 1996.

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First Report of Raspberry bushy dwarf virus in Rubus multibracteatus from China

Plant Disease ◽

10.1094/pdis.2003.87.5.603a ◽

2003 ◽

Vol 87 (5) ◽

pp. 603-603 ◽

Cited By ~ 13

Author(s):

C. J. Chamberlain ◽

J. Kraus ◽

P. D. Kohnen ◽

C. E. Finn ◽

R. R. Martin

Keyword(s):

Amino Acid ◽

Coat Protein ◽

Coat Protein Gene ◽

Protein Gene ◽

Dwarf Virus ◽

Enzyme Linked Immunosorbent Assay ◽

Black Raspberry ◽

First Report ◽

Raspberry Bushy Dwarf Virus ◽

Plant Pathol

Raspberry bushy dwarf virus (RBDV), genus Idaeovirus, has been reported in commercial Rubus spp. from North and South America, Europe, Australia, New Zealand, and South Africa. Infection can cause reduced vigor and drupelet abortion leading to crumbly fruit and reduced yields (3,4). In recent years, Rubus germplasm in the form of seed, was obtained on several collection trips to The People's Republic of China to increase the diversity of Rubus spp. in the USDA-ARS National Clonal Germplasm Repository, (Corvallis, OR). Before planting in the field, seedlings were tested for the presence of RBDV, Tomato ringspot virus, and Tobacco streak virus using triple-antibody sandwich enzyme-linked immunosorbent assay (TAS-ELISA) (antiserum produced by R. R. Martin). One symptomless plant of R. multibracteatus H. Lev. & Vaniot (PI 618457 in USDA-ARS GRIN database), from Guizhou province in China, tested positive for RBDV (RBDV-China). After mechanical transmission on Chenopodium quinoa Willd., this isolate produced typical symptoms of RBDV (3). To determine if RBDV-China was a contaminant during the handling of the plants, or if the source was a seedborne virus, the coat protein gene was sequenced and compared to published sequences of RBDV. RNA was extracted from leaves of R. multibracteatus and subjected to reverse transcription-polymerase chain reaction (RT-PCR) using primers that flank the coat protein gene. Products from four separate PCR reactions were sequenced directly or were cloned into the plasmid vector pCR 2.1 (Invitrogen, Carlsbad, CA) and then sequenced. The coding sequence of the coat protein gene of RBDV-China was 87.5% (722/825) identical to that isolated from black raspberry (Genbank Accession No. s55890). The predicted amino acid sequences were 91.6% (251/274) identical. Previously, a maximum of five amino acid differences had been observed in the coat proteins of different RBDV strains (1). The 23 differences observed between RBDV-China and the isolate from black raspberry (s55890) confirm that the RBDV in R. multibracteatus is not a greenhouse contaminant but is indeed a unique strain of RBDV. In addition, monoclonal antibodies (MAbs) to RBDV (2) were tested against RBDV-China. In these tests, MAb D1 did not detect RBDV-China, whereas MAb R2 and R5 were able to detect the strain. This is the first strain of RBDV that has been clearly differentiated by MAbs using standard TAS-ELISA tests. Although RBDV is common in commercial Rubus spp. worldwide, to our knowledge, this is the first report of RBDV in R. multibracteatus, and the first report of RBDV from China. The effects of this new strain of RBDV could be more or less severe, or have a different host range than previously studied strains. It is more divergent from the type isolate than any other strain that has been studied to date. Phylogenetic analysis of coat protein genes of RBDV may be useful in understanding the evolution and spread of this virus. References: (1) A. T. Jones et al. Eur. J. Plant Pathol. 106:623, 2000. (2) R. R. Martin. Can. J. Plant. Pathol. 6:264, 1984. (3) A. F. Murant. Raspberry Bushy Dwarf. Page 229 in: Virus Diseases of Small Fruits. R. H. Converse, ed. U.S. Dep. Agric. Agric. Handb. 631, 1987. (4) B. Strik and R. R. Martin. Plant Dis. 87:294, 2003.

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First Report of Cherry virus A and Little cherry virus-1 in Poland

Plant Disease ◽

10.1094/pdis.2004.88.8.909c ◽

2004 ◽

Vol 88 (8) ◽

pp. 909-909 ◽

Cited By ~ 12

Author(s):

B. Komorowska ◽

M. Cieślińska

Keyword(s):

Nucleotide Sequence ◽

Coat Protein ◽

Coat Protein Gene ◽

Protein Gene ◽

Germplasm Collection ◽

Mottle Virus ◽

Enzyme Linked Immunosorbent Assay ◽

Rt Pcr ◽

First Report ◽

Primer Sets

Cherry virus A (CVA), a member of the genus Capillovirus, has been reported in sweet cherry in Germany, Canada, and Great Britain. No data are available on the effects of CVA on fruit quality and yield of infected trees. Little cherry disease (LChD) occurs in most cherry growing areas of the world. Symptoms on sensitive cultivars include discolored fruit that remain small, pointed in shape, and tasteless. Three Closterovirus spp. associated with LChD have been described (Little cherry virus-1 [LChV-1], LChV-2, and LChV-3). Diseased local and commercial cultivars of sour cherry trees were found in a Prunus sp. germplasm collection and orchards in Poland during the 2003 growing season. The foliar symptoms included irregular, chlorotic mottling, distortion, and premature falling of leaves. Some of the diseased trees developed rosette as a result of decreased growth and shortened internodes. Severely infected branches exhibited dieback symptoms. Because the symptoms were suggestive of a possible virus infection, leaf samples were collected from 38 trees and assayed for Prune dwarf virus and Prunus necrotic ringspot virus using double antibody sandwich enzyme-linked immunosorbent assay (DAS-ELISA). RNA extracted from leaves was used in a reverse transcription-polymerase chain reaction (RT-PCR) with the One-Step RT-PCR with Platinum Taq (Invitrogen Life Technologies) and primer sets specific for CVA (1), LChV-1 (3), and LChV-2 (3). The RNA samples were also tested using RT-PCR for detection of Cherry mottle leaf virus (CMLV), Cherry necrotic rusty mottle virus (CNRMV), and Cherry green ring mottle virus (CGRMV) with specific primer sets (2). Amplification of a 397-bp coat protein gene product confirmed infection of 15 trees with CVA. A 419-bp fragment corresponding to the coat protein gene of LChV-1 was amplified from cv. Gisela rootstock and local cv. WVIII/1. To confirm RT-PCR results, CVA amplification products from local cv. WX/5 and LChV-1 from cvs. Gisela and WVIII/1 were cloned in bacterial vector pCR 2.1-TOPO and then sequenced. The sequences were analyzed with the Lasergene (DNASTAR, Madison, WI) computer program. The alignment indicated that the nucleotide sequence of cv. WX/5 was closely related to the published sequences of CVA (Genbank Accession No. NC_003689) and had an 89% homology to the corresponding region. The nucleotide sequence similarity between the 419-bp fragment obtained from cvs. Gisela and WVIII/1 was 87% and 91%, respectively, compared with the reference isolate of LChV-1 (Genbank Accession No. NC_001836). The sampled trees tested negative for LChV-2, CGRMV, CMLV, and CNRMV using RT-PCR. Some trees tested positive for PNRSV and PDV. To our knowledge, this is the first report of CVA and LChV-1 in Poland. References: (1) D. James and W. Jelkmann. Acta Hortic. 472:299, 1998. (2) M. E. Rott and W. Jelkmann. Eur. J. Plant Pathol. 107:411,2001. (3) M. E. Rott and W. Jelkmann. Phytopathology. 91:61, 2001.

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Molecular cloning and nucleotide sequence of coat protein gene of turnip mosaic virus

Nucleic Acids Research ◽

10.1093/nar/18.18.5555 ◽

1990 ◽

Vol 18 (18) ◽

pp. 5555-5555 ◽

Cited By ~ 12

Author(s):

Ling-Jie Kong ◽

Rong-Xiang Fang ◽

Zheng-Hua Chen ◽

Ke-Qiang Mang

Keyword(s):

Nucleotide Sequence ◽

Coat Protein ◽

Mosaic Virus ◽

Molecular Cloning ◽

Coat Protein Gene ◽

Protein Gene ◽

Turnip Mosaic Virus

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Isolation and Molecular Characterization of a Chilean Isolate of Zucchini yellow mosaic virus

Plant Disease ◽

10.1094/pdis.2001.85.6.644 ◽

2001 ◽

Vol 85 (6) ◽

pp. 644-648 ◽

Cited By ~ 6

Author(s):

H. Prieto ◽

A. Bruna ◽

P. Hinrichsen ◽

C. Muñoz

Keyword(s):

Coat Protein ◽

Mosaic Virus ◽

Coat Protein Gene ◽

Protein Gene ◽

Zucchini Yellow Mosaic Virus ◽

Yellow Mosaic Virus ◽

Enzyme Linked Immunosorbent Assay ◽

Sequence Comparisons ◽

Severe Stunting ◽

Chilean Isolate

Zucchini yellow mosaic virus (ZYMV) was described in 1981 affecting squash, melon, and other cultivated cucurbits with severe stunting and yellowing symptoms. It was reported to be present in most countries where cucurbits are grown, and in Chile since 1995, from surveys using enzyme-linked immunosorbent assay (ELISA) but without further characterization. A potyvirus was isolated from ELISA-positive symptomatic plants. The results indicate that this virus is ZYMV based on symptoms on herbaceous indicators, immunospecific electron microscopy of the purified particle, and sequencing of 395 bases of the 3′ end of the coat protein gene. The virus was detected in melon, watermelon, and squash plants. In agreement with previous descriptions for ZYMV, the Chilean isolate is a flexuous filamentous particle 740 nm long with one main protein of approximately 36 kDa. Nucleotide sequence comparisons of the 3′ portion of the coat protein gene revealed a high similarity to the Connecticut and California strains.

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First Report of Turnip mosaic virus on Watercress in Brazil

Plant Disease ◽

10.1094/pdis-94-8-1066a ◽

2010 ◽

Vol 94 (8) ◽

pp. 1066-1066 ◽

Cited By ~ 2

Author(s):

H. Costa ◽

J. A. Ventura ◽

A. S. Jadão ◽

J. A. M. Rezende ◽

A. P. O. A. Mello

Keyword(s):

Coat Protein ◽

Mosaic Virus ◽

Leaf Size ◽

Turnip Mosaic Virus ◽

Polyclonal Antiserum ◽

Cauliflower Mosaic Virus ◽

Mechanical Transmission ◽

Rt Pcr ◽

First Report ◽

Coat Protein Region

Watercress (Nasturtium officinale L.), a member of the family Brassicaceae, is consumed mainly as salad. Medicinal properties have also been attributed to this species. In Brazil, watercress is grown mainly by very small farmers. The crop is primarily seed propagated and growers can harvest several times per year in an established planting. Very few diseases have been reported in this crop worldwide. In Brazil, watercress infection by Cauliflower mosaic virus (CaMV) (3), Cucumber mosaic virus (CMV) (1), and an unidentified potyvirus (2) were previously reported. In January 2009, 80% of watercress plants, cv. Gigante Redondo, exhibiting severe mosaic, leaf size reduction, and plant stunting were observed in a crop in Marechal Floriano Municipality, State of Espírito Santo, Brazil. Preliminary leaf dip analysis by transmission electron microscopy revealed the presence of potyvirus-like particles. Sap from five infected plants reacted in plate-trapped antigen (PTA)-ELISA with polyclonal antiserum against Turnip mosaic virus (TuMV), but not with antiserum against CMV. Both antisera were produced in the Plant Virology Laboratory, ESALQ/USP. Mechanically inoculated watercress plants developed similar systemic mosaic symptoms. The virus was also transmitted to Nicotiana benthamiana, which exhibited severe mosaic and stunting. The presence of TuMV on these inoculated plants was confirmed by PTA-ELISA and reverse transcription (RT)-PCR. Total RNA extracted from infected and healthy watercress and infected N. benthamiana was analyzed by RT-PCR using specific pairs of primers flanking the coat protein gene of TuMV. Degenerated anti-sense (5′-t/caacccctt/gaacgcca/cagt/ca-3′) and sense (5′-gcaggtgaa/gacg/acttgat/ca/gc-3′) primers were designed after analysis to an alignment of the nucleotide sequences for five isolates of TuMV available in the GenBank (Accession Nos. NC_002509, D10927, EU680574, AB362513, and D88614). One fragment of 838 bp was amplified from samples in the infected plants, but not in the healthy controls. Two amplicons were purified and directly sequenced in both directions. Comparisons of the 731-bp consensus nucleotide sequence (Accession No. HM008961) to several other isolates of TuMV revealed 94 to 95% identity in the coat protein region. To our knowledge, this is the first report of TuMV in watercress in Brazil. Management of the disease should include propagation by seeds instead of vegetative parts of the plants and rouging of diseased plants to prevent mechanical transmission during successive harvestings. References: (1) A. J. Boari et al. Fitopatol. Bras. 25:438, 2000. (2) A. J. Boari et al. Fitopatol. Bras. 27:S200, 2002. (3) M. L. R. Z. C. Lima et al. Fitopatol. Bras. 9:403, 1984.

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