scholarly journals Nicotiana megalosiphon, a Highly Susceptible, New, and Useful Host for Potato Virus A

Plant Disease ◽  
2004 ◽  
Vol 88 (10) ◽  
pp. 1160-1160 ◽  
Author(s):  
P. E. Thomas
Keyword(s):  
The Netherlands ◽  
Potato Virus ◽  
Virus Disease ◽  
Plant Viruses ◽  
Enzyme Linked Immunosorbent Assay ◽  
Mechanical Transmission ◽  
Virus Concentration ◽  
Potato Virus A ◽  
Seed Potatoes ◽  
Nicandra Physalodes

Potato virus A (PVA; genus Potyvirus, family Potyviridae) occurs wherever potatoes are grown and may reduce tuber yields as much as 40%. Its host range consists of six experimental hosts (Lycopersicon pimpinellifolium (Jusl.) P. Mill., Nicandra physalodes (L.) Gaertn., Nicotiana tabacum L., Solanum demissum Lindl., S. demissum × S. tuberosum [2], and Nicotiana debneyi Domin.) and two natural hosts (S. tuberosum L. and S. betaceae (Cav.) Sendt.) (2). Aphids transmit PVA in a stylet-born manner. Its difficult mechanical transmission, caused by a low virus concentration in potato and other hosts (1), has constrained pathological research on the virus. In routine studies to identify virus isolates from the field, we discovered that N. megalosiphon Van Heurck & Mull. Agr. is a superior host of PVA that markedly facilitated diagnosis, selection for resistance to PVA, and other research applications. The efficiency of mechanical transmission of PVA to potato (5 duplicated assays and 10 plants per assay) ranged from 0 to 10% with PVA-infected potato as the virus source, 0 to 30% with Nicandra physalodes, 10 to 30% with N. tabacum cv. Samsun, and 20 to 80% with N. megalosiphon as the source of virus. The efficiency of mechanical transmission to four systemic hosts of PVA with potato (cv. Russet Burbank) as the source of virus (5 duplicated assays and 10 plants per assay) ranged from 0 to 20% to potato, 0 to 30% to Nicandra physalodes, 10 to 40% to N. tabacum cv. Samsun, and 80 to 100% to N. megalosiphon. The superiority of N. megalosiphon as a host and source of PVA was associated with a high virus concentration in tissues. Infected potato leaves yielded 0.32 to 0.54 mg of virus per kg of infected leaves, Nicandra physalodes yielded 0.37 to 0.66 mg per kg, N. tabacum cv. Samsun yielded 0.78 to 1.22 mg per kg, and N. megalosiphon yielded 5.16 to 9.39 mg per kg of infected leaves in five different purification experiments. These yields are based on the amount of virus isolated in sucrose gradients subjected to rate-zonal centrifugation as the last step in purification (3). The virus antigen concentrations of the original PVA-infected tissues measured using quantitative enzyme-linked immunosorbent assay ranked virus concentrations in the same relative order as purification but were nearly 2 times higher than were the purification yields. Similarly, local lesion assays on S. demissum A leaves (4) ranked infectious virus concentrations in the same order as did purification. Efficiency of aphid transmission from the four hosts was not assayed. Infected N. megalosiphon plants survived and served as sources of PVA for at least 1 year in a greenhouse. N. megalosiphon is an important new host of PVA because it facilitates the routine transmission of the virus and other manipulations essential for efficient research on control of the virus disease. References: (1) R. Bartels. No. 54 in: Descriptions of Plant Viruses. CMI, Kew, Surrey, UK, 1971. (2) A. Brunt. Page 77 in: Virus and Virus-Like Diseases of Potatoes and Production of Seed Potatoes. G Loebenstein et al., eds. Kluwer Academic Publishers, Dordrecht, the Netherlands, 2001. (3) P. E. Thomas and W. K. Kaniewski. Page 285 in: Virus and Virus-Like Diseases of Potatoes and Production of Seed Potatoes, G. Loebenstein et al., eds. Kluwer Academic Publishers, Dordrecht, the Netherlands, 2001. (4) R. E. Webb and R. W. Buck. Am Potato J. 32:248, 1955.

scholarly journals First Report on Natural Occurrence of Tomato Spotted Wilt Tospovirus in Basil (Ocimum basilicum)

Plant Disease ◽  
1999 ◽  
Vol 83 (10) ◽  
pp. 966-966 ◽  
Author(s):  
G. E. Holcomb ◽  
R. A. Valverde ◽  
J. Sim ◽  
J. Nuss
Keyword(s):  
Plant Viruses ◽  
Ocimum Basilicum ◽  
Enzyme Linked Immunosorbent Assay ◽  
Mechanical Transmission ◽  
Summer Drought ◽  
Natural Occurrence ◽  
Thin Sections ◽  
First Report ◽  
Tomato Spotted Wilt ◽  
National University

Virus-like symptoms were observed on basil plants (Ocimum basilicum L. ‘Mrs. Burns Lemon’ [MBL]) growing in containers and a demonstration plot at the Louisiana State University Burden Research Plantation, Baton Rouge, during July 1998. Symptoms consisted of ring spots, leaf distortion, and severe mosaic. Mechanical transmission of the suspect virus by sap inoculation from infected MBL to basil cvs. MBL, Aussie Sweet, Cinnamon, Siam Queen, and Sweet Dani was successful. Symptoms were similar to those on infected MBL. Nicotiana benthamiana Domin. reacted with local chlorotic spots followed by severe yellows, necrosis, and death. Electron microscopy of thin sections of infected basil revealed virus inclusions but no virus particles. However, infected N. benthamiana revealed the presence of 82-nm membrane-bound particles in the cytoplasm. The virus was identified from basil and N. benthamiana as the common strain of tomato spotted wilt tospovirus (TSWV) by enzyme-linked immunosorbent assay (Agdia, Elkhart, IN). An outbreak of thrips insects during the summer drought in 1998 was probably responsible for the occurrence of TSWV in basil. This is the first report of the occurrence of TSWV in basil (1). Reference: (1) A. A. Brunt et al., eds. 1996. Plant Viruses Online: Descriptions and Lists from the VIDE Database. Published online by Australian National University, Canberra.

scholarly journals Differential Accumulation of Potato virus A and Expression of Pathogenesis-Related Genes in Resistant Potato cv. Shepody upon Graft Inoculation

2001 ◽  
Vol 91 (2) ◽  
pp. 197-203 ◽  
Author(s):  
Xianzhou Nie ◽  
Rudra P. Singh
Keyword(s):  
Gene Expression ◽  
Potato Virus ◽  
Solanum Tuberosum L ◽  
Virus Concentration ◽  
Temperature Dependent ◽  
Susceptible Host ◽  
Potato Virus A ◽  
Chitinase A ◽  
Pathogenesis Related ◽  
Pathogenesis Related Gene

Potato (Solanum tuberosum L.) cv. Shepody is highly resistant to Potato virus A (PVA), yielding no visible symptoms after rub inoculation. In ‘Shepody’ rootstocks graft-inoculated by PVA-infected scions from a susceptible host, we found a resistance consisting of traces of necrosis (necrotic streaks) in stems and chlorosis in newly emerged leaves. The response was temperature dependent, appearing at 15 to 18°C but not at 28 to 31°C. Necrosis was also observed in tubers, appearing first in the bud end and spreading randomly throughout the majority of the tuber. Trace amounts of PVA in plant tissues were detected by a combination of reverse transcription polymerase chain reaction and Southern blot procedures. The virus concentration was significantly higher in visibly necrotic areas than in nonnecrotic areas, suggesting that presence of the necrosis may be concentration dependent. Pathogenesis-related gene expression showed that chitinase A and B, glucanase B, and PR-10a were associated with chlorotic or necrotic symptoms in leaves, stems, and tubers. Gene expression was markedly more evident in tuber tissues than in leaves and stems. Furthermore, generation of oxidants was also observed within the necrotic areas. Although PVA was detected in necrotic areas of tubers, newly emerged plants from the same tubers were PVA-free.

scholarly journals Survival and Transmission of Potato Virus Y, Pepino Mosaic Virus, and Potato Spindle Tuber Viroid in Water

2013 ◽  
Vol 80 (4) ◽  
pp. 1455-1462 ◽  
Author(s):  
N. Mehle ◽  
I. Gutiérrez-Aguirre ◽  
N. Prezelj ◽  
D. Delić ◽  
U. Vidic ◽  
...  
Keyword(s):  
Mosaic Virus ◽  
Potato Virus ◽  
Plant Pathogens ◽  
Potato Virus Y ◽  
Potato Spindle Tuber Viroid ◽  
Plant Viruses ◽  
Detection Methods ◽  
Mechanical Transmission ◽  
Pepino Mosaic Virus ◽  
Viroid Infection

ABSTRACTHydroponic systems and intensive irrigation are used widely in horticulture and thus have the potential for rapid spread of water-transmissible plant pathogens. Numerous plant viruses have been reported to occur in aqueous environments, although information on their survival and transmission is minimal, due mainly to the lack of effective detection methods and to the complexity of the required transmission experiments. We have assessed the role of water as a source of plant infection using three mechanically transmissible plant pathogens that constitute a serious threat to tomato and potato production: pepino mosaic virus (PepMV), potato virus Y (PVY), and potato spindle tuber viroid (PSTVd). PepMV remains infectious in water at 20 ± 4°C for up to 3 weeks, PVY (NTN strain) for up to 1 week, and PSTVd for up to 7 weeks. Experiments using a hydroponic system show that PepMV (Ch2 genotype) and PVY (NTN strain) can be released from plant roots into the nutrient solution and can infect healthy plants through their roots, ultimately spreading to the green parts, where they can be detected after a few months. In addition, tubers developed on plants grown in substrate watered with PSTVd-infested water were confirmed to be the source of viroid infection. Our data indicate that although well-known pathways of virus spread are more rapid than water-mediated infection, like insect or mechanical transmission through leaves, water is a route that provides a significant bridge for rapid virus/viroid spread. Consequently, water should be taken into account in future epidemiology and risk assessment studies.

scholarly journals Identification and Molecular Characterization of a Potyvirus Isolated from Native Larkspur (Delphinium glaucum) in Alaska

Plant Disease ◽  
2009 ◽  
Vol 93 (4) ◽  
pp. 428-428 ◽  
Author(s):  
N. L. Robertson ◽  
K. L. Brown
Keyword(s):  
Amino Acid ◽  
Potato Virus ◽  
Native Plants ◽  
Mechanical Transmission ◽  
Protease Gene ◽  
Western Blots ◽  
Potato Virus A ◽  
Vein Clearing ◽  
Putative Coat Protein ◽  
Potyvirus Species

Wild larkspur, Delphinium glaucum S. Watson, grows throughout most of Alaska along roadsides and in forests and is planted as an ornamental. Leaves containing distinct vein-clearing and chlorotic mosaic symptoms were first noticed on several D. glaucum plants during 2000 at the Georgeson Botanical Garden in Fairbanks, AK. Although affected plants continued to produce normal flowers, by 2008, the plants developed overall stunting. Initially, virus presence was determined by a general differential centrifugation extraction and concentration protocol followed by examination of the partially purified virus and leaf sap by electron microscopy. Filamentous particles approximately 725 nm long were observed. Virion protein extractions analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis revealed a putative coat protein (CP) of ~35 kDa. Potyvirus identity (family Potyviridae) was confirmed with universal potyvirus antiserum in western blots and ELISA assays (Agdia, Inc., Elkhart, IN). Exotic larkspur plants, D. elatum L., growing next to diseased D. glaucum plants, did not exhibit symptoms nor were they positive for potyvirus when tested serologically as described previously. Total RNA was extracted from potyvirus-infected leaves and used in reverse transcriptase-PCR assays that specifically targeted potyviruses (2,4) to generate genomic segments for identification and sequence analysis. Fragments representing portions of the helper component protease gene, HC-Pro (~700 bp), the cylindrical inclusion gene, CI (~700 bp), and the 3′-end (~1.7 kbp) were purified, cloned, sequenced, and deposited in GenBank (Accession Nos. FJ349329, FJ349328, and FJ349327, respectively). The sequenced 3′-end (1,674 nt) revealed a partial nuclear inclusion protein gene, NIb (1 to 630 nt), a CP gene (631 to 1,443 nt), and a 3′-untranslated region (1,447 to 1,674 nt) attached to a poly (A) tail. Blast searches in GenBank for percent identities of the nucleotide and amino acid comparisons resulted in highest similarities in conserved regions among members in the genus Potyvirus. For example, the highest CI, CP, and HP amino acid identities (0 gaps) were 67% with Potato virus A (Accession No. AF543709), 74% with Araujia mosaic virus (Accession No. EF710625), and 65% with Potato virus A (Accession No. AJ131403), respectively. However, none of the identities were sufficient for inclusion with an existing potyvirus species, whereby the CP amino acid sequence identity must be at least 80% (1). Mechanical transmission of purified virus to Chenopodium amaranticolor, C. quinoa, D. elatum, D. glaucum, and Nicotiana benthamiana seedlings was unsuccessful. We conclude that the isolated virus is a new species in the genus Potyvirus and propose the name Delphinium vein-clearing virus (DeVCV). To our knowledge, this is the first report of a virus isolated from D. glaucum and is representative of the growing number of viruses found in native plants (3). The distribution of DeVCV-infected larkspur is not known in managed or natural ecosystems. Identification of new viruses from native plants is important, in that, the host plant may act as a virus reservoir for transmission to other ornamental and crop plants. References: (1) P. H. Berger et al. Family Potyviridae. Page 819 in: Virus Taxonomy-8th Report of the ICTV. C. M. Fauquet et al., eds. Elsevier Academic Press, San Diego, CA, 2005. (2) J. Chen et al. Arch. Virol. 146:757, 2001. (3) I. Cooper and A. C. Jones. Adv. Virus Res. 67:1, 2006. (4) C. Ha et al. Arch. Virol. 153:25, 2008.

scholarly journals First Reports of Soilborne wheat mosaic virus and Wheat spindle streak mosaic virus in Africa

Plant Disease ◽  
2000 ◽  
Vol 84 (8) ◽  
pp. 921-921 ◽  
Author(s):  
R. G. Kapooria ◽  
J. Ndunguru ◽  
G. R. G Clover
Keyword(s):  
Triticum Aestivum ◽  
Mosaic Virus ◽  
Wheat Yield ◽  
Plant Viruses ◽  
Enzyme Linked Immunosorbent Assay ◽  
Infected Leaf ◽  
Mechanical Transmission ◽  
Panicum Maximum ◽  
Wheat Cultivars ◽  
Das Elisa

During 1997 and 1998, virus symptoms similar to those of Soilborne wheat mosaic virus (SBWMV) and Wheat spindle streak mosaic virus (WSSMV) were observed on nine wheat cultivars (Triticum aestivum cvs. Deka, Gamtoos, Lorie II, MM2, Nata, Nkwazi, P7, Scepter, and Scan) in the Central, Copper-Belt, Lusaka, and Southern provinces of Zambia. Symptoms were observed between June and August on wheat, which in Zambia is an irrigated crop grown during the cooler months (May to August). In fields suspected to be infected with SBWMV, irregularly distributed, circular patches of severely stunted sparse plants were observed. Because of these symptoms, the syndrome is described in Zambia as the “crater disease.” Infection was more common on light to medium sandy-loam clay soils, and affected patches were particularly common along the field edges and in poorly drained areas. Such waterlogged conditions are conducive to the multiplication and spread of Polymyxa graminis, the protist vector of SBWMV (1). Affected plants initially showed chlorotic streaks on all leaves, which became uniformly yellow and eventually necrotic. The roots of these plants were slightly swollen and enlarged and are likened to “Rastafarian pleats” locally. In fields suspected to be infected with WSSMV, symptomatic plants were observed in the border rows of affected fields. Chlorotic streaks and mosaics were observed on the leaves of affected plants, and the tips of these leaves were also frequently twisted. Using double antibody sandwich enzyme-linked immunosorbent assay (DAS-ELISA), SBWMV and WSSMV were positively identified in symptomatic plants. In total, 81 plants from the four provinces were tested, and 72 and 37% were infected with SBWMV and WSSMV, respectively. Identification was confirmed by DAS-ELISA using antisera from W. Huth (BBA-Braunschweig, Germany) and C. Rubies-Autonell (Bologna University, Italy) for SBWMV and using antisera from W. Huth (BBA-Braunschweig, Germany) and G. Bergstrom (Cornell University, New York) for WSSMV. Further confirmation of the identity of the two viruses was provided by the reaction of 12 indicator species (Chenopodium amaranticolor, C. quinoa, C. hybridum, Digitaria milanjiana, Eleusine indica, Oryza sativa (cv. IITA 212), Panicum maximum, Rottboellia cochinchinensis, Setaria verticillata, Sorghum bicolor(cv. Sima), S. halepense, and Triticum aestivum (cvs. Lucal, Kwale, Lorie II, Nkanga, 128, and GV 4–12) in mechanical transmission studies using infected leaf sap. This is the first report of SBWMV and WSSMV not only in Zambia but also Africa. The area of wheat grown in Zambia has risen in the past several years to approximately 18,000 ha per annum. However, annual wheat yield (60,000 tons) has not risen to match this increase. The effect of SBWMV and WSSMV on yield in Zambia has not yet been measured, but both viruses cause serious losses in other countries (1–3) and the severity of the symptoms suggests that significant yield reductions are likely. Furthermore, no Zambian wheat cultivars are known to be resistant to either virus. Generally, wheat production fails to meet demand in the country and therefore further yield losses due to virus infection could be disastrous. References: (1) M. K. Brakke. CMI/AAB Desc. of Plant Viruses 77, 1971. (2) J. T. Slykhuis. Phytopathology 60:319, 1970. (3) V. Vallega and C. Rubies-Autonell. Plant Dis. 69:64, 1985.

Detection of Hepatitis a Virus in Drinking Water by Enzyme -Immunoassay Using Ultracentrifugation for Virus Concentration

1985 ◽  
Vol 17 (10) ◽  
pp. 39-41 ◽  
Author(s):  
A. Schnattinger
Keyword(s):  
Membrane Filtration ◽  
Hepatitis A ◽  
Hepatitis A Virus ◽  
Solid Phase ◽  
Phosphate Buffer Solution ◽  
Enzyme Linked Immunosorbent Assay ◽  
Virus Concentration ◽  
Buffer Solution ◽  
Solution Ph ◽  
Two Stage

Ten litres of tapwater were seeded with 200 µl (8×108 HAV particles) of a commercial (Organon Teknika) suspension of hepatitis A virus. Following WALTER and RÜDIGER (1981), the contaminated tapwater was treated with a two-stage technique for concentration of viruses from solutions with low virus titers. The two-stage technique consists of aluminium hydroxideflocculation (200 mg/l Al2(SO4)3. 18 H2O, pH 5,4-5,6) as first stage, the second stage of a lysis of aluminium hydroxidegel with citric acid/sodium citrate-buffer (pH 4,7; 1 ml/l sample), separation of viruses from the lysate by ultracentrifugation and suspension in 1 ml phosphate buffer solution (pH 7,2). A commercial solid phase enzyme-linked immunosorbent assay (ELISA) was used for the detection of HAV. HAV was detecterl in the 10.000:1 concentrates, but not in the seeded 101 samples. Approximately 4×108 of the inoculated 8×108 HAV particles were found in the 1 ml concentrates. The efficiency of detection is about 50%, the virus concentration 5000-fold. Although the percentage loss of HAV in comparison with concentration by means of membrane filtration is similar, the ultracentrifugation method yields a larger sample/concentrate ratio, so that smaller amounts of HAV can be detected more efficiently because of the smaller end-volume.

scholarly journals Incidence and distribution of Sweetpotato viruses and their implication on sweetpotato seed system in Malawi

2021 ◽  
Author(s):  
Willard Mbewe ◽  
Andrew Mtonga ◽  
Margret Chiipanthenga ◽  
Kennedy Masamba ◽  
Gloria Chitedze ◽  
...  
Keyword(s):  
Sweet Potato ◽  
Virus Disease ◽  
Disease Incidence ◽  
Mottle Virus ◽  
Enzyme Linked Immunosorbent Assay ◽  
Foliar Symptoms ◽  
Membrane Enzyme ◽  
Sweet Potato Virus ◽  
Seed System ◽  
Clean Seed

AbstractA survey was carried out in 19 districts to investigate the prevalence and distribution of sweetpotato virus disease (SPVD) and its implication on the sustainability of clean seed system in Malawi. A total of 166 leaf samples were collected and tested for the presence of 8 viruses using nitrocellulose membrane enzyme-linked immunosorbent assay (NCM-ELISA). SPVD foliar symptoms were observed in 68.42% of the surveyed districts. There were significant variations in disease incidence and severity (p < 0.001) among districts, with the highest incidence in Mulanje (28.34%). Average SPVD severity score was 3.05. NCM-ELISA detected sweet potato feathery mottle virus (SPFMV, 30.54%), sweet potato mild mottle virus (SPMMV, 31.14%), sweet potato mild speckling virus (SPMSV, 16.17%), sweet potato C-6 virus (SPC6V, 13.77%), sweet potato chlorotic stunt virus (SPCSV, 22.16%), sweet potato collusive virus (SPCV, 30.54%), sweet potato virus G (SPVG, 11.38%), cucumber mosaic virus (CMV, 7.78%) either in single or mixed infections. Data from this study indicate a significant SPVD occurrence in the country, and the consequence implications towards national sweetpotato seed system.

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