Tobacco Streak Ilarvirus Research Articles

First report of Tobacco streak ilarvirus infecting jasmine and horse gram

During the rainy season of 2012, symptoms resembling viral infection were observed on two crops - Jasminum sambac (jasmine) and Macrotyloma uniflorum (horse gram) at Cheruvu Belagal and Kadiri mandals of Kurnool and Anantapuram districts…

First report of Tobacco streak ilarvirus infecting onion (Allium cepa)

Tobacco streak ilarvirus (TSV) is a member of the genus Ilarvirus (family Bromoviridae ) and consists of non-enveloped, isometric particles, approximately 25 to 35 nm in diameter. TSV has a wide host range, infecting more than 200 plant…

Virus-associated Diseases of Double Petunia: Frequency and Distribution in Ohio Greenhouses

Double petunia plants expressing virus-like symptoms were collected in greenhouses and garden centers throughout Ohio in Spring 1997 and 1998 in an effort to determine the frequency and distribution of petunia viruses present in the state. Direct antibody-sandwich and indirect enzyme-linked immunosorbent assay (ELISA) were conducted with commercial antisera made against 13 viruses, a potyvirus kit capable of detecting 80 different potyviruses, and our antiserum raised against a tobamo-like virus inducing severe mosaic in double petunia. Viral-associated double-stranded ribonucleic acid (dsRNA) analysis and light microscopy for detection of inclusion bodies were also carried out. ELISA, dsRNA analysis, and light microscopy revealed the presence of tobacco mosaic tobamovirus, an unknown tobamo-like petunia virus, tomato ringspot nepovirus, tobacco streak ilarvirus, and tobacco ringspot nepovirus. Tomato aspermy cucumovirus, tomato spotted wilt tospovirus, impatiens necrotic spot tospovirus, alfalfa mosaic virus, cucumber mosaic cucumovirus, potato virus X potexvirus, and chrysanthemum B carlavirus were not detected. No potyviruses were identified. A number of plants with virus-like symptoms tested negative for all viruses.

Serological and coat protein sequence studies suggest that necrosis disease on sunflower in India is caused by a strain of Tobacco streak ilarvirus.

Serological and coat protein sequence studies were conducted to identify an ilarvirus associated with necrosis disease on sunflower in India. In electroblot immunoassay, sunflower ilarvirus reacted strongly only with antiserum to Tobacco streak virus (TSV). The coat protein gene of sunflower ilarvirus was cloned and sequenced. The sequence analyses also showed that the CP gene was most closely related to TSV, the member of subgroup I of Ilarvirus. The sunflower ilarvirus CP shared 90% amino acid sequence identity with TSV. On the basis of serological relatedness and sequence identity, it is proposed that the sunflower ilarvirus from India should be considered a strain of TSV belonging to subgroup I and designated as TSV-SF. This is the first report of the molecular characterization of TSV on sunflower from the Indian subcontinent.

Virus Assessment of Ajuga reptans Cultivars Reveals Alfalfa Mosaic, Tobacco Streak, and Cucumber Mosaic (CMV) Viruses, and a CMV Satellite RNA

Ajuga reptans L. is an herbaceous ornamental mint grown in borders or as a groundcover, and is commonly propagated vegetatively and by seed. Three hundred and fifty-six A. reptans samples were obtained from growers in Washington, Michigan, Iowa, and Ohio, and screened for alfalfa mosaic virus (AMV), tobacco streak ilarvirus (TSV), cucumber mosaic cucumovirus (CMV), tomato aspermy cucumovirus (TAV), tomato spotted wilt tospovirus (TSWV), impatiens necrotic spot tospovirus (INSV), tobacco mosaic tobamovirus (TMV), potato virus × potexvirus (PVX), and 80 potyviruses, using direct antibody sandwich (DAS) and indirect enzyme-linked immunosorbent assay (ELISA). Viral-associated double-stranded ribonucleic acid (dsRNA) analysis was used to detect an apparent satellite (sat) RNA, and northern hybridization using a digoxigenin (DIG) labeled (S) CARNA-5 cDNA probe was used to confirm the identity of the apparent satRNA. No incidences of TAV, TMV, TSWV, INSV, PVX, or potyviruses were detected. CMV was detected in 11%, AMV in 22.2%, TSV in 3.7%, and mixed infections of CMV and AMV in 1.1% of the samples. SatRNA was detected in 36 A. reptans `Royalty', two `Rainbow', and two `Burgundy Glow' samples by dsRNA analysis, and confirmed by hybridization in 29 `Royalty' and one `Burgundy Glow' samples. Sixteen A. reptans `Royalty' seedlings grown from seed harvested from CMV-infected plants were tested by ELISA for CMV, AMV, and TSV. All were positive for CMV, and two were positive for a mixed infection of CMV and AMV. SatRNA was detected in all 16 seedlings by RT-PCR.

Virus infections reduce in vitro multiplication of ‘Malling Landmark’ raspberry

Virus-infected plants are often symptomless and may be inadvertently used as explant sources in tissue culture research. Our objective was to determine the effect of virus infection on micropropagation. We studied the effects of single and multiple infections of three common raspberry viruses on the in vitro culture of ‘Malling Landmark’ red raspberry (Rubus idaeus L.). Virus-infected reaspberry plants were produced by leaf-graft inoculation from known-infected plants onto virus-free ‘Malling Landmark’. Single-virus source plants were infected with either tobacco streak ilarvirus (TSV), tomato ringspot nepovirus (TomRSV), or raspberry bushy dwarf idaeovirus (RBDV) and were free of other viruses as determined by enzyme-linked immunosorbent assay (ELISA) and bioassay. Virus-free, single, and multiple virus-infected ‘malling Landmark’ explants were initiated into culture and multiplied on Anderson's medium with 8.9 μM N6-benzyladenine (BA). At the end of the multiplication tests, ELISA reconfirmed virus infections. In vitro multiplication of ‘Malling Landmark’ was significantly reduced by multiple infections, and multiplication of plants infected with all three viruses (RBDV+TomRSV+TSV) was less than half that of virus free cultures. Shoot height and morphology of in vitro cultures were not influenced by virus infection. The greenhouse stock plant with the three-virus infection was stunted and yellow compared to the control and the other infected plants.

First Report of Tobacco Streak Ilarvirus from Honeysuckle.

A honeysuckle (Lonicera fragrantissima) shrub on the grounds of the former Plant Quarantine Station, Glenn Dale, MD, had chlorotic leaves on some shoot tips and a mild veinal chlorosis. Young leaves were triturated in buffer and rub-inoculated onto a series of potential indicator hosts. The virus incited necrotic local lesions and necrosis of the growing point in Chenopodium quinoa, etched ringspots on inoculated leaves of Nicotiana tabacum Xanthi nc, mosaic in Zinnia violacea, and chlorotic local lesions in Tetragonia tetragonioides. It did not infect any of 46 other herbaceous genera in families Cucurbitaceae, Fabaceae, Asteraceae, Solanaceae, or Brassicaceae. In gel diffusion tests with symptomatic leaves from tobacco, this virus reacted with antiserum to tobacco streak virus (TSV) HR strain, but did not react with antisera to alfalfa mosaic or with antisera to 12 viruses in the NEPO or Sobemovirus groups. Virus in leaves directly from the source shrubs, tested by enzyme-linked immunosorbent assay (ELISA), also reacted with TSV strain HF antiserum. Examination by electron microscopy of leaf dips revealed isometric particles 27 nm in diameter. The now 12-ft tall shrubs were grown from seed imported from China in 1914 (PI 40689). This species is now widely commercially available in the U.S. and grown for its fragrant late winter flowers (2). Viral-infected Lonicera spp. have been reported from Europe, Russia, Japan, and Canada (1). TSV is reported to be seed-borne in several other genera. Among other viruses reported from honeysuckle are Lonicera latent carlavirus, tobacco leaf curl geminivirus, alfalfa mosaic virus, tomato bushy stunt virus, a rhabdovirus, and an aphid transmitted virus.

Biological and physicochemical properties of cowpea severe mosaic comovirus isolated from soybean in the State of Paraná

Soybean plants with symptoms of bud blight were growing close to cowpea with severe symptoms of mosaic associated with blisters in the leaves. A group of plants of both species were collected and used for etiological studies. This kind of symptom in soybeans was common in certain areas of the State of Parana, induced by tobacco streak ilarvirus. Host range, serological reaction, particle morphology and size, protein and nucleic acid analysis, and transmission by beetles from species Cerotoma arcuata Oliv. showed that the virus involved was cowpea severe mosaic comovirus. This is the first report on the occurrence of this virus in soybean plants in the State of Parana. Results using indirect ELISA showed that in cowpea the relative virus concentration was higher in green leaf areas than in chlorotic ones. Also, virus concentration, determined through indirect ELISA was much higher in plants kept at diurnal regime of 25o C x 23o C (12 x 12 h) than at 30o C x 28o C.

Cucumber Mosaic Virus, Tobacco Streak Virus, and Cucumber Mosaic Virus Satellite RNA Associated with Mosaic and Ringspot Symptoms in Ajuga reptans in Ohio.

Creeping bugleweed (Ajuga reptans L.) is a perennial ornamental commonly grown as a ground cover in temperate climates. Commercial samples of the A. reptans cultivars Royalty, var. Atropurpurea Bronze, Bronze Beauty, and Burgundy Glow showing mosaic and ringspot symptoms were tested for the presence of virus infection by direct antibody sandwich enzyme-linked immunosorbent assay (ELISA) and viral-associated double-stranded (ds) RNA analysis. Cucumber mosaic cucumovirus (CMV) was detected by ELISA and dsRNA analysis in symptomatic samples of all cultivars tested. ELISA values were considered positive if the absorbance values were twice the negative control. Negative control values were established with asymptomatic tissue of the cv. Bronze Beauty. Tobacco streak ilarvirus (TSV) was detected only by ELISA in symptomatic samples of all cultivars except Royalty. No dsRNA suggestive of TSV was detected. Alfalfa mosaic virus (AMV) was detected by ELISA and dsRNA analysis in symptomatic samples of all cultivars tested except Royalty and var. Atropurpurea Bronze. dsRNA analysis also indicated the presence of a low molecular weight, possible satellite (sat) RNA associated with all symptomatic and asymptomatic Royalty and var. Atropurpurea Bronze plants tested. Northern (RNA) blot analysis with a digoxigenin-labeled full-length clone of the (S) CARNA-5 (-) CMV satRNA (ATCC no. 45124) confirmed that the low molecular weight RNA associated with the Royalty and var. Atropurpurea Bronze cultivars was indeed CMV satRNA. Only AMV has been previously reported in A. reptans in the United States (1). This is the first report of CMV and its satRNA, as well as TSV, in A. reptans in the United States. Reference: (1) W. T. Schroeder and R. Provvidenti. Plant Dis. Rep. 56:285, 1972.

Transmission of Three Strains of Tobacco Streak Ilarvirus by Different Thrips Species Using Virus‐infected Pollen

AbstractWhen cucumber seedlings were dusted with tobacco streak ilarvirus (TSV)‐infected pollen and infested with 5–10 thrips (adults and larvae mixed), Thrips tabaci transmitted all three Australian strains of TSV. In similar work, Microcephalothrips abdominalis transmitted both and Frankliniella schultzei one strain, respectively, of two TSV strains tested. Transmission of the Ageratum strain (TSV‐Ag) infecting pollen of Ageratum houstonianum was very efficient (100%) by all three thrips species. However, transmission rates of only 0–28% were achieved using the Ajuga strain (TSV‐A) and the strawberry strain (TSVS) in pollen of other hosts. A fourth thrips species, T. parvispinus, transmitted TSV‐Ag from infected tomato pollen to Chenopodium amaranticolor seedlings. There was, therefore, little or no vector specificity in the thrips transmission of the three strains of TSV, but factors associated with the virus‐infected pollen affected the efficiency of transmission. This is the first report of F. schultzei and T. parvispinus as vectors of TSV.

Distribution of Tobacco Streak, Tomato Ringspot, and Raspberry Bushy DwarfViruses inRubus ursinusandR. leucodermisCollected from the Pacific Northwest

Clonal and seed propagules of Rubus ursinus, the trailing blackberry, and seed of R. leucodermis, the western black raspberry, were collected from throughout the Pacific Northwest (Oregon, Washington, and British Columbia). The collections were made in four general environmental regions: at sea level along the Pacific coast, in the coastal mountains adjacent to the coast, in the Willamette Valley, and in the Cascade Mountains. After the resulting propagules were established, leaves were tested by enzyme-linked immunosorbent assay according to standard procedures. None of the R. leucodermis samples tested positive for raspberry bushy dwarf idaeovirus (RBDV), tomato ringspot nepovirus (TomRV), or tobacco streak ilarvirus (TSV). Rubus leucodermis is either resistant to these viruses or their vectors, the viruses are not seed transmitted in this species, or the viruses were not detected due to inadequate sampling. No samples of R. ursinus tested positive for RBDV or TomRV. Samples from 77% of the sites where cuttings were taken and 37% of the seedling populations tested positive for TSV. Along the Pacific coast, only 20% of the sites sampled by cuttings tested positive for TSV. However, the percentage of infected sites where cuttings were taken increased to 88 and 100% in the coastal mountains and the Cascade Mountains, respectively. Along the Pacific coast, 14% of seedling sites tested positive for TSV. The number of TSV positive seedling sites increased to 45 and 36% in the Cascade Mountains and the coastal mountains, respectively. The Willamette Valley site tested negative for TSV. With one exception, all of the low elevation sites tested negative for TSV. Prevailing winds or earlier flowering may prevent some of these Pacific Coast populations from becoming infected. Many of the TSV positive sites had some samples that tested negative, indicating that TSV is unevenly distributed within these populations.

Studies on the mechanism of transmission of pollen‐associated tobacco streak ilarvirus virus by Thrips tabaci

Mixed instars of Thrips tabaci were allowed to feed on test seedlings of cucumber, the thrips were removed and wounds caused by thrips feeding dusted with tobacco streak virus (TSV) carried in tomato pollen. Transmission of TSV occurred in three out of the four experiments conducted. When Chenopodium amaranticolor test seedlings were dusted with infective tomato pollen, and thrips introduced for varying periods before being killed with insecticide, TSV transmission occurred after exposure to thrips for 1 h, 5 h, 1 day or 2 days, but not 5 min. Pollen‐washing experiments indicated that TSV was carried both internally and externally in pollen of tomato and several weed hosts. T. tabaci was able to transmit TSV from pollen of Nicotiana clevelandii and Nicandra physalodes, and TSV from tomato pollen was transmitted to several weed species. It is concluded that T. tabaci transmits TSV associated with tomato pollen by a mechanical mechanism whereby virus carried externally, or released from inside the pollen, infects feeding wounds.

Failure of Five Viruses to Cause Typical Australian Papaw Dieback Disease.

When the leaves of 4- to 6-weeks-old papaw seedlings were mechanically inoculated with sap extracts containing tobacco ringspot Nepovirus (TRSV), tobacco streak Ilarvirus (TSV), tomato spotted wilt Tospovirus (TSWV), lettuce necrotic yellows Rhabdovirus (LNYV) or solanum nodiflorum mottle Sobemovirus (SNMV), infection of some of the papaw seedlings resulted with TRSV,TSWV and TSV, but not with LNW and SNMV. However, LNW was transmitted to papaw seedlings by its aphid vectors, Hyperomyzus spp., without causing symptoms. Symptoms produced by TRSV and TSWV were similar, but not identical, to those shown by plants with naturally occurring Australian dieback disease. Infection by TSV caused a mild mottle. It is concluded that none of the five viruses is the likely cause of Australian papaw dieback disease.

Association Between Tobacco Streak Ilarvirus Seed Transmission and Anther Tissue Infection in Bean

Tobacco streak ilarvirus (TSV) seed transmission was investigated by reciprocal pollinations as well as by serological and infectivity assays of flower parts from beans (Phaseolus vulgaris) systematically infected with either TSV pathotype I (isolate Mel 40) or TSV pathotype II (isolate Mel F). Heathly and TSV-infected Black Turtle Soup (BTS) bean plants were reciprocally pollinated by using anthers from either heathly plants or plants systematically infected with Mel 40 or Mel F. When anthers from plants infected with Mel 40 were used to pollinate heathly plants, a high percentage of the resulting seedlings were infected with that isolate (...)