Accumulation of necrotic lesion inducing variants in TMV-infected plantlets derived from leaf disks of Nicotiana sylvestris

1989 ◽  
Vol 67 (4) ◽  
pp. 984-989 ◽  
Author(s):  
Iqrar A. Khan ◽  
Gary E. Jones
Keyword(s):  
Tobacco Mosaic Virus ◽  
Mosaic Virus ◽  
Rna Virus ◽  
Leaf Tissue ◽  
Nicotiana Sylvestris ◽  
Wild Type Virus ◽  
Type Virus ◽  
Variant Type ◽  
Whole Plants ◽  
Leaf Disks

In an isolate of tobacco mosaic virus strain U1 there exists a small subpopulation containing a variant strain of the virus that induces the hypersensitive response on Nicotiana sylvestris Spegazzini & Comes. This type of variant is strongly selected for during the regeneration of plantlets from mature leaf tissue of plants infected with tobacco mosaic virus U1. When whole plants derived from disks were transferred into a glasshouse, those containing this type of variant were severely stunted, showed mosaic symptoms, and most of them died. Some that had originally contained lower titers of variant-type virus survived to flower but produced only a few seeds. Plants that initially contained only wild-type virus had high titers of tobacco mosaic virus, survived and grew well, exhibited mosaic symtoms, and flowered and set seed normally. Repeated assays of virus in these plants revealed no detectable variant-type virus. Apparently, during callus development and organogenesis in culture, partial segregation of the mixed U1 population occurred, and variants preferentially infected the developing tissues. This represents a situation in which dramatic change in the genetic structure of an RNA virus population occurs during development of the host plant.

Tobacco Mosaic Virus-Infected Tissue

1985 ◽  
Vol 43 ◽  
pp. 510-511
Author(s):  
Egbert W. Henry
Keyword(s):  
Nicotiana Tabacum ◽  
Tobacco Mosaic Virus ◽  
Chlorogenic Acid ◽  
Mosaic Virus ◽  
Host Resistance ◽  
Oxidative Metabolism ◽  
Leaf Tissue ◽  
Vein Clearing ◽  
Basal Septum ◽  
Concentration Levels

Tobacco mosaic virus (TMV) infection has been studied in several investigations of Nicotiana tabacum leaf tissue. Earlier studies have suggested that TMV infection does not have precise infective selectivity vs. specific types of tissues. Also, such tissue conditions as vein banding, vein clearing, liquification and suberization may result from causes other than direct TMV infection. At the present time, it is thought that the plasmodesmata, ectodesmata and perhaps the plasmodesmata of the basal septum may represent the actual or more precise sites of TMV infection.TMV infection has been implicated in elevated levels of oxidative metabolism; also, TMV infection may have a major role in host resistance vs. concentration levels of phenolic-type enzymes. Therefore, enzymes such as polyphenol oxidase, peroxidase and phenylalamine ammonia-lyase may show an increase in activity in response to TMV infection. It has been reported that TMV infection may cause a decrease in o-dihydric phenols (chlorogenic acid) in some tissues.

THE INCORPORATION OF p-FLUOROPHENYLALANINE INTO TOBACCO MOSAIC VIRUS

1962 ◽  
Vol 40 (8) ◽  
pp. 999-1004 ◽  
Author(s):  
P. M. Townsley
Keyword(s):  
Amino Acid ◽  
Tobacco Mosaic Virus ◽  
Mosaic Virus ◽  
Leaf Tissue ◽  
Free Fraction ◽  
Natural Amino Acid ◽  
Agar Gel ◽  
Tobacco Leaf ◽  
Zone Electrophoresis ◽  
Reduced Rate

Disks of diseased tobacco leaf tissue were treated with phenylalanine and with the analogue p-fluorophenylalanine. The expressed sap was separated into its components by agar gel zone electrophoresis. p-Fluorophenylalanine was shown to be incorporated into TMV at a reduced rate as compared with the natural amino acid phenylalanine. The analogue inhibited incorporation of phosphorus, a reversal probably due to the increase in phenylalanine observed in the soluble amino-acid-free fraction.

Selection for a specific tobacco mosaic virus variant during bolting of Nicotiana sylvestris

1989 ◽  
Vol 67 (1) ◽  
pp. 88-94 ◽  
Author(s):  
Iqrar A. Khan ◽  
Gary E. Jones
Keyword(s):  
Tobacco Mosaic Virus ◽  
Mosaic Virus ◽  
Nicotiana Sylvestris ◽  
Hypersensitive Reaction ◽  
Genetic Composition ◽  
Virus Variant ◽  
Clonal Population ◽  
Rna Transcripts ◽  
Selection For ◽  
Small Subpopulation

In an isolate of tobacco mosaic virus, TMV U1, a small subpopulation of virus that invokes the hypersensitive reaction on Nicotiana sylvestris Spegaz. & Comes exists and is strongly selected for during replication in plants that are undergoing development of shoot axes during bolting. Virus of this phenotype (NL) can infect and move systemically in rapidly developing parts of N. sylvestris plants and is strongly selected for in upper tissues of the plants only during the development of the shoot axis. This selection results in a dramatic change in the genetic composition of the virus population in the upper part of the plant. No accumulation of NL-type virus occurred when N. sylvestris plants were inoculated with TMV204, a clonal population derived from RNA transcripts of a plasmid carrying a cDNA copy of the TMV genome.

THE INCORPORATION OF p-FLUOROPHENYLALANINE INTO TOBACCO MOSAIC VIRUS

1962 ◽  
Vol 40 (1) ◽  
pp. 999-1004
Author(s):  
P. M. Townsley
Keyword(s):  
Amino Acid ◽  
Tobacco Mosaic Virus ◽  
Mosaic Virus ◽  
Leaf Tissue ◽  
Free Fraction ◽  
Natural Amino Acid ◽  
Agar Gel ◽  
Tobacco Leaf ◽  
Zone Electrophoresis ◽  
Reduced Rate

Disks of diseased tobacco leaf tissue were treated with phenylalanine and with the analogue p-fluorophenylalanine. The expressed sap was separated into its components by agar gel zone electrophoresis. p-Fluorophenylalanine was shown to be incorporated into TMV at a reduced rate as compared with the natural amino acid phenylalanine. The analogue inhibited incorporation of phosphorus, a reversal probably due to the increase in phenylalanine observed in the soluble amino-acid-free fraction.

Ultrastructural study of tobacco mosaic virus-infected chloroplasts

1984 ◽  
Vol 42 ◽  
pp. 328-329
Author(s):  
Egbert W. Henry
Keyword(s):  
Nicotiana Tabacum ◽  
Tobacco Mosaic Virus ◽  
Mosaic Virus ◽  
Host Resistance ◽  
Phenylalanine Ammonia Lyase ◽  
Leaf Tissue ◽  
Vein Clearing ◽  
Tissue Responses ◽  
Basal Septum ◽  
Tissue Abnormalities

There have been several reports on the effects of tobacco mosaic virus (TMV) infection in Nicotiana tabacum leaf tissue. TMV infection does not appear to have an exact or precise infective selectivity, with respect to particular tissues. The tissue abnormalities such as lignification, suberization, vein banding, and vein clearing, may not be direct tissue responses to TMV infection. However, it has been suggested that plasmodesmata and possibly ectodesmata, may represent the actual sites of TMV infection, especially the plasmodesmata of the basal septum.TMV infection has also been implicated in host resistance vs. the levels of phenolic-type enzymes. A rise in oxidative metabolism has been associated with TMV infection, thus causing an increase in the, activity of peroxidase, polyphenol oxidase and phenylalanine ammonia-lyase. In addition, TMV infection may cause a lowering of o-dihydric phenols such as chlorogenic acid in some tissues.

scholarly journals Quantitative Real-Time PCR Analysis of Individual Flue-Cured Tobacco Seeds and Seedlings Reveals Seed Transmission of Tobacco Mosaic Virus

2020 ◽  
Vol 110 (1) ◽  
pp. 194-205 ◽  
Author(s):  
Madeleine D. Ellis ◽  
Jessica M. Hoak ◽  
Bradley W. Ellis ◽  
Jessica A. Brown ◽  
Tim L. Sit ◽  
...  
Keyword(s):  
Tobacco Mosaic Virus ◽  
Mosaic Virus ◽  
Seed Coat ◽  
Rna Virus ◽  
Seed Transmission ◽  
Pcr Analysis ◽  
Infected Seed ◽  
Tobacco Seed ◽  
Individual Seed ◽  
Tobacco Seeds

Tobacco mosaic virus (TMV) is an extensively studied RNA virus known to infect tobacco (Nicotiana tabacum) and other solanaceous crops. TMV has been classified as a seedborne virus in tobacco, with infection of developing seedlings thought to occur from contact with the TMV-infected seed coat. The mechanism of TMV transmission through seed was studied in seed of the K 326 cultivar of flue-cured tobacco. Cross pollinations were performed to determine the effect of parental tissue on TMV infection in seed. Dissection of individual tobacco seeds into seed coat, endosperm, and embryo was performed to determine TMV location within a seed, while germination tests and separation of the developing seedling into seed coat, roots, and cotyledons were conducted to estimate the percent transmission of TMV. A reverse-transcriptase quantitative PCR (RT-qPCR) assay was developed and used to determine TMV concentrations in individual seed harvested from pods that formed on plants from TMV-infected and noninfected crosses. The results showed maternal transmission of TMV to tobacco seed and seedlings that developed from infected seed, not paternal transmission. RT-qPCR and endpoint PCR assays were also conducted on the separated seed coat, endosperm, and embryo of individual seed and separated cotyledons, roots, and seed coats of individual seedlings that developed from infected tobacco seed to identify the location of the virus in the seed and the subsequent path the virus takes to infect the developing seedling. RT-qPCR and endpoint PCR assay results showed evidence of TMV infection in the endosperm and embryo, as well as in the developing seedling roots and cotyledons within 10 days of initiating seed germination. To our knowledge, this is the first report of TMV being detected in embryos of tobacco seed, demonstrating that TMV is seedborne and seed-transmitted in flue-cured tobacco.

scholarly journals RELATIONSHIPS BETWEEN TOBACCO MOSAIC VIRUS AND THE NON-VIRUS PROTEINS

1955 ◽  
Vol 38 (4) ◽  
pp. 475-492 ◽  
Author(s):  
Barry Commoner ◽  
Sidney D. Rodenberg
Keyword(s):  
Tobacco Mosaic Virus ◽  
Mosaic Virus ◽  
Experimental Error ◽  
Leaf Tissue ◽  
Infected Leaf ◽  
Tobacco Leaf ◽  
Biochemical Processes ◽  
Cross Reactions ◽  
Immunochemical Techniques ◽  
Virus Proteins

1. The non-virus proteins, A4, B3, and B6, characteristically found in tobacco leaf infected with TMV exhibit specific immunochemical cross-reactions with serum prepared against the virus. The close immunochemical relations which occur among these proteins do not extend to any normal tobacco leaf proteins. 2. The rate of appearance of the non-virus proteins in newly infected cultured leaf tissue at various times after inoculation has been determined by immunochemical techniques and by direct isolation of the proteins. Both methods give comparable results. The non-virus proteins appear abruptly at about 220 hours after inoculation, when the TMV content is about one-third its final value. The amount of A4 rises rapidly and then levels off. The B6 content rises rapidly and continuously over the course of the experiment. B3 appears last, and increases in amount considerably more slowly than A4 and B6. 3. The isotope contents of TMV, B3, and B6 which appear in given intervals after inoculation in newly infected leaf cultured in nutrient containing N15H4 have been compared. The isotope levels of concurrent TMV, B3, and B6 are identical within the experimental error. The isotope conditions employed in this experiment lead to the conclusion that this coincidence of N15 levels means that the virus and non-virus proteins are probably synthesized at about the same time from the same non-protein source of nitrogen. 4. Possible interpretations of the available data on the non-virus proteins are discussed. It is likely that one or more of these proteins represents small protein units which occur in the TMV nucleoprotein.As they exist in the infected leaf, the non-virus proteins are probably no longer available to the biochemical processes which lead to TMV synthesis. They are probably not precursors of TMV protein in a temporal sense.

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