The appearance of eight strains of alfalfa mosaic virus in alfalfa leaves and their effect on the ultrastructure of infected cells

1974 ◽  
Vol 52 (5) ◽  
pp. 979-985 ◽  
Author(s):  
Roy D. Wilcoxson ◽  
F. I. Frosheiser ◽  
Lois B. Johnson
Keyword(s):  
Mosaic Virus ◽  
Alfalfa Mosaic Virus ◽  
Leaf Tissue ◽  
Cell Organelles ◽  
Virus Particles ◽  
Vascular Parenchyma ◽  
Infected Cells ◽  
Medicago Sativa L ◽  
Ultrastructural Damage ◽  
Apparently Healthy

Eight strains of alfalfa mosaic virus (AMV) were studied by electron microscopy in alfalfa (Medicago sativa L.) leaf tissue and after purification. The virus occurred in the cytoplasm and occasionally in the vacuoles of mesophyll and vascular parenchyma cells; it was not associated with cell organelles. One strain of AMV (U5) did not incite symptoms in the alfalfa leaves and caused no ultrastructural damage to the infected cells. Two strains (U10 and U21) caused no symptoms in alfalfa, but the tonoplast of infected cells was not closely attached to the cytoplasm and floated in the vacuole; cell organelles were not damaged. The other five strains of AMV (F1, NY1, R6, B1, and W1) regularly or occasionally produced symptoms in alfalfa leaves. In leaves that were symptomless, as well as in the apparently healthy parts of leaves with symptoms of AMV infection, there was no apparent ultrastructural damage to the infected cells. Within the part of a leaf where there were symptoms, the tonoplast was detached from the cytoplasma and was folded within the vacuole in various patterns, along with bits of cytoplasm and virus particles. Cell organelles were often found in various stages of disintegration. Three different aggregations of the virus were recognized. The eight AMV strains were grouped into three general classes on the basis of the range in virus particle sizes. Mycoplasm was not associated with any of the AMV strains.

Ultrastructural Changes in Leaf Tissues of Populusdeltoides spp. angulata Ait. Infected with Poplar Mosaic Virus

1972 ◽  
Vol 2 (3) ◽  
pp. 308-312 ◽  
Author(s):  
S. Navratil ◽  
M. G. Boyer
Keyword(s):  
Endoplasmic Reticulum ◽  
Mosaic Virus ◽  
Ultrastructural Changes ◽  
Cell Organelles ◽  
Sieve Elements ◽  
Virus Particles ◽  
Chloroplast Membrane ◽  
Leaf Tissues ◽  
Infected Cells

Ultrastructural observations on the foliar cells of Populusdeltoides spp. angulata Ait. infected by poplar mosaic virus revealed a high content of virus particles in the cytoplasm of most but not all young cells from chlorotic areas. Mature cells from necrotic areas contained far fewer virions while in symptomless green portions no virions were observed. Virus particles were not found in mature sieve elements or in mature nonliving xylem cells.Changes in the cytoplasm and in chloroplasts were followed. Healthy, mature chloroplasts contained well developed thylakoid systems. In infected cells, a disintegrative process at necrotization resulted in the dissolution of the thylakoid system into individual electron dense sacs which were released when the chloroplast membrane dissolved. Cytoplasmic changes were characterized by increased vacuolation. Cisternae of the endoplasmic reticulum and vesiculate bodies were also more numerous. Necrotization was accompanied by dissolution of the cell organelles.

scholarly journals Detection of Poinsettia mosaic virus Infecting Poinsettias (Euphorbia pulcherrima) in Venezuela

Plant Disease ◽  
2001 ◽  
Vol 85 (11) ◽  
pp. 1208-1208 ◽  
Author(s):  
O. Carballo ◽  
M. L. Izaguirre ◽  
E. Marys
Keyword(s):  
Mosaic Virus ◽  
Leaf Tissue ◽  
Enzyme Linked Immunosorbent Assay ◽  
Euphorbia Pulcherrima ◽  
Leaf Extracts ◽  
Thin Sections ◽  
Virus Particles ◽  
Transmission Electron ◽  
Rugose Mosaic ◽  
Infected Cells

Poinsettia mosaic virus (PnMV), a putative member of the tymoviruses, was detected in several cultivars of vegetatively propagated poinsettias grown in commercial nurseries in Estado Miranda, Venezuela. Symptoms associated with the affected plants consisted of severe mottling and distortion of leaves and bracteoles. The suspect virus was mechanically transmitted to Nicotiana benthamiana. Leaf extracts and thin sections of affected leaf tissue were analyzed by transmission electron microscopy. Spherical virus particles (30 nm diameter) were observed in samples from symptomatic poinsettia plants. Ultrastructural analyses of virus-infected cells revealed aggregates of virus particles in the cytoplasm and central vacuole. The virus was purified twice from infected N. benthamiana, resulting in yields as high as 12 mg/100 g. Dissociated coat protein contained a single 24-kDa protein species. The virus was not serologically related to Carnation mottle, Bean rugose mosaic, Cowpea mosaic, Cucumber mosaic, Pea enation mosaic, Prunus necrotic ringspot, Apple mosaic, Tobacco streak, Maize rayado fino, Tomato ringspot, Bean southern mosaic, Sowbane mosaic, Andean potato latent, Belladona mottle, Scrophularia or Turnip yellow mosaic viruses, but did react positively in enzyme-linked immunosorbent assay and western blot analysis with antiserum (ATCC PVAS-476) to PnMV. Based on these results, the virus is considered to be PnMV. To our knowledge, this is the first report of PnMV infecting poinsettias in Venezuela.

scholarly journals Capped mRNAs with Reduced Secondary Structure Can Function in Extracts from Poliovirus-Infected Cells

1982 ◽  
Vol 2 (12) ◽  
pp. 1633-1638 ◽  
Author(s):  
Nahum Sonenberg ◽  
Denise Guertin ◽  
Kevin A. W. Lee
Keyword(s):  
Secondary Structure ◽  
Mosaic Virus ◽  
Hela Cells ◽  
Alfalfa Mosaic Virus ◽  
Stable Secondary Structure ◽  
Ribosome Binding ◽  
Infected Cells

Extracts from poliovirus-infected HeLa cells were used to study ribosome binding of native and denatured reovirus mRNAs and translation of capped mRNAs with different degrees of secondary structure. Here, we demonstrate that ribosomes in extracts from poliovirus-infected cells could form initiation complexes with denatured reovirus mRNA, in contrast to their inability to bind native reovirus mRNA. Furthermore, the capped alfalfa mosaic virus 4 RNA, which is most probably devoid of stable secondary structure at its 5′ end, could be translated at much higher efficiency than could other capped mRNAs in extracts from poliovirus-infected cells.

ELECTRON MICROSCOPY OF TWO SMALL SPHERICAL PLANT VIRUSES IN THIN SECTIONS

1966 ◽  
Vol 44 (6) ◽  
pp. 821-826 ◽  
Author(s):  
J. R. Edwardson ◽  
D. E. Purcifull ◽  
R. G. Christie
Keyword(s):  
Electron Microscopy ◽  
Mosaic Virus ◽  
Leaf Tissue ◽  
Plant Viruses ◽  
Tobacco Necrosis Virus ◽  
Necrosis Virus ◽  
Thin Sections ◽  
Virus Particles ◽  
Southern Bean Mosaic Virus

Particles within lesions of leaf tissue infected with either tobacco necrosis virus (TNV) or southern bean mosaic virus (SBMV) were compared with particles in embedded pellets of purified preparations of these viruses by an examination of thin sections. The mode of the diameters of particles in tissues and pellets was 20.5 mµ.It is assumed that the particles in infected tissues are virus particles on the basis of their similarities in size, shape, and arrangement with the particles in purified preparations.

Capped mRNAs with Reduced Secondary Structure Can Function in Extracts from Poliovirus-Infected Cells

1982 ◽  
Vol 2 (12) ◽  
pp. 1633-1638
Author(s):  
Nahum Sonenberg ◽  
Denise Guertin ◽  
Kevin A. W. Lee
Keyword(s):  
Secondary Structure ◽  
Mosaic Virus ◽  
Hela Cells ◽  
Alfalfa Mosaic Virus ◽  
Stable Secondary Structure ◽  
Ribosome Binding ◽  
Infected Cells

Extracts from poliovirus-infected HeLa cells were used to study ribosome binding of native and denatured reovirus mRNAs and translation of capped mRNAs with different degrees of secondary structure. Here, we demonstrate that ribosomes in extracts from poliovirus-infected cells could form initiation complexes with denatured reovirus mRNA, in contrast to their inability to bind native reovirus mRNA. Furthermore, the capped alfalfa mosaic virus 4 RNA, which is most probably devoid of stable secondary structure at its 5′ end, could be translated at much higher efficiency than could other capped mRNAs in extracts from poliovirus-infected cells.

scholarly journals First Report of Alfalfa mosaic virus Infection in Viburnum tinus in Chile

Plant Disease ◽  
2011 ◽  
Vol 95 (9) ◽  
pp. 1198-1198 ◽  
Author(s):  
E. Peña ◽  
E. Olate ◽  
R. A. Chorbadjian ◽  
I. M. Rosales
Keyword(s):  
Mosaic Virus ◽  
Alfalfa Mosaic Virus ◽  
Leaf Tissue ◽  
Aphid Species ◽  
Molecular Probes ◽  
Rt Pcr ◽  
Water Control ◽  
Tissue Samples ◽  
Aphis Spiraecola ◽  
Blastn Analysis

Viburnum tinus L., commonly known as laurustinus, is an ornamental shrub that is widely used as a garden plant and flower crop. V. tinus is popular because of its desirable characteristics such as evergreen foliage, tolerance to pruning, winter blooms, and its adaptation to cold temperate zones. It is also relatively easy to grow and is commonly used as a windbreak. Infection of this ornamental species by Alfalfa mosaic virus (AMV) has been associated with yellow mottling or variegated leaf coloring, including light green and white, and has been referred to as the “Viburnum Calico” (1,4). In April 2011, at the onset of winter in the Southern Hemisphere, intense yellow spotting and mottling was observed on V. tinus leaves in the San Joaquin Campus at Pontificia Universidad Catolica de Chile. Presence of Aphis spiraecola Patch was observed on the shrubs, however, in the area it is also common to find other aphid species such as Toxoptera aurantii (Boyer de Fonscolombe) and A. fabae Scopoli. Leaf tissue samples from 10 asymptomatic and 10 symptomatic plants were examined for the presence of AMV by tissue-blot immunoassay with a commercially available polyclonal antibody (Agdia Inc., Elkhart, IN) along with the Goat affinity purified anti-rabbit IgG conjugated (Whole Molecule) (Molecular Probes, Invitrogen Corp., Carlsbad, CA). First-strand cDNA synthesis and PCR were performed with specific primers CP-AMV1 and CP-AMV2 (3). AMV was detected in all symptomatic leaves and also in two of the asymptomatic tissue analyzed by tissue blot assay. Reverse transcription (RT)-PCR produced 753-bp amplicons in all samples that were positive to AMV by tissue printing. No amplification product was observed when water control or seronegative samples were used as templates in the RT-PCR assays. Two amplicons were directly sequenced in both directions to confirm the identification of AMV in the leaf samples. The sequences obtained were homologous and BLASTN analysis of the submitted sequence (GenBank Accession No. JN040542) showed 99% nucleotide sequence identity to an AMV isolate described from Nicotiana tabacum L. (GenBank Accession No. FJ527749). These results demonstrate the presence of AMV in V. tinus in Chile. This pathogen has also been described to be affecting V. tinus in France (1) and V. lucidum Mill. in Spain (2). In Chile, V. tinum is increasingly grown as an ornamental plant. Therefore, care should be taken to ensure that the propagative materials of V. tinum are devoid of AMV infection to prevent further spread of this virus. References: (1) L. Cardin et al. Plant Dis. 90:1115, 2006. (2) M. Cebrián et al. Plant Dis. 92:1132, 2008. (3) M. Finetti-Sialer et al. J. Plant Pathol. 79:115, 1997. (4) H. E. Williams et al. Phytopathology 61:1305, 1971.

The application of ultracryotomy in the study of the fine structure of intracellular virus particles: mouse mammary tumor virus (MMTV)

1978 ◽  
Vol 36 (2) ◽  
pp. 366-367
Author(s):  
T. Hanaichi ◽  
M. Hoshino ◽  
S. Nakamura ◽  
Y. Nishi ◽  
M. Imai ◽  
...  
Keyword(s):  
Negative Staining ◽  
Cell Organelles ◽  
Mammary Tumor Virus ◽  
Thin Sections ◽  
Virus Particles ◽  
The Past ◽  
Mouse Mammary Tumor ◽  
Tumor Virus ◽  
Infected Cells ◽  
Intracellular Virus

For the electron microscopy of intracellular virus particles, two techniques have mainly been used; thin sections of plastic- embedded, virus-infected cells and negative staining of the virus particles isolated by disrupting the infected cells. For the observation of minute structures of the particles at high magnification, the latter is often far superior to the former. However, the latter requires the destruction of relations of virus particles to the surrounding cell organelles and may result in the observation of the particles in a distorted state due to the loss of certain materials related to the virus during the isolation process. Ultracryotomy, developed for the past decade, takes advantage of the process of negative staining for the detection of complex intracellular structures at a high resolution. This led us to apply technique to the study of the virus-infected cells. This paper will report the detailed ultrastructures of MMTV at different stages of evolution in the infected cells as revealed by the ultracryotomy technique.

scholarly journals Identification of distinct steps during tubule formation by the movement protein of Cowpea mosaic virus

2003 ◽  
Vol 84 (12) ◽  
pp. 3485-3494 ◽  
Author(s):  
Jeroen Pouwels ◽  
Noortje Kornet ◽  
Nikkie van Bers ◽  
Teun Guighelaar ◽  
Jan van Lent ◽  
...  
Keyword(s):  
Plasma Membrane ◽  
Mosaic Virus ◽  
Movement Protein ◽  
Cell Movement ◽  
Cowpea Mosaic Virus ◽  
Tubule Formation ◽  
Virus Particles ◽  
Cell Localization ◽  
Support Cell ◽  
Infected Cells

The movement protein (MP) of Cowpea mosaic virus (CPMV) forms tubules through plasmodesmata in infected plants thus enabling virus particles to move from cell to cell. Localization studies of mutant MPs fused to GFP in protoplasts and plants identified several functional domains within the MP that are involved in distinct steps during tubule formation. Coinoculation experiments and the observation that one of the C-terminal deletion mutants accumulated uniformly in the plasma membrane suggest that dimeric or multimeric MP is first targeted to the plasma membrane. At the plasma membrane the MP quickly accumulates in peripheral punctuate spots, from which tubule formation is initiated. One of the mutant MPs formed tubules containing virus particles on protoplasts, but could not support cell-to-cell movement in plants. The observations that this mutant MP accumulated to a higher level in the cell than wt MP and did not accumulate in the cell wall opposite infected cells suggest that breakdown or disassembly of tubules in neighbouring, uninfected cells is required for cell-to-cell movement.

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