scholarly journals Tobacco Mosaic Virus Replicase-Auxin/Indole Acetic Acid Protein Interactions: Reprogramming the Auxin Response Pathway To Enhance Virus Infection

2007 ◽  
Vol 82 (5) ◽  
pp. 2477-2485 ◽  
Author(s):  
Meenu S. Padmanabhan ◽  
Sabrina R. Kramer ◽  
Xiao Wang ◽  
James N. Culver
Keyword(s):  
Acetic Acid ◽  
Tobacco Mosaic Virus ◽  
Mosaic Virus ◽  
Protein Interactions ◽  
Indole Acetic Acid ◽  
Leaf Tissue ◽  
Infection Process ◽  
Disease Development ◽  
Virus Accumulation ◽  
Cellular Environment

ABSTRACT The replicase protein of Tobacco mosaic virus (TMV) disrupts the localization and stability of interacting auxin/indole acetic acid (Aux/IAA) proteins in Arabidopsis, altering auxin-mediated gene regulation and promoting disease development (M. S. Padmanabhan, S. P. Goregaoker, S. Golem, H. Shiferaw, and J. N. Culver, J. Virol. 79:2549-2558, 2005). In this study, a similar replicase-Aux/IAA interaction affecting disease development was identified in tomato. The ability of the TMV replicase to interact with Aux/IAA proteins from diverse hosts suggests that these interactions contribute to the infection process. To examine the role of this interaction in virus pathogenicity, the replication and spread of a TMV mutant with a reduced ability to interact with specific Aux/IAA proteins were examined. Within young (4- to 6-week-old) leaf tissue, there were no significant differences in the abilities of Aux/IAA-interacting or -noninteracting viruses to replicate and spread. In contrast, in mature (10- to 12-week-old) leaf tissue, the inability to interact with specific Aux/IAA proteins correlated with a significant reduction in virus accumulation. Correspondingly, interacting Aux/IAA levels are significantly higher in older tissue and the overaccumulation of a degradation-resistant Aux/IAA protein reduced virus accumulation in young leaf tissue. Combined, these findings suggest that TMV replicase-Aux/IAA interactions selectively enhance virus pathogenicity in tissues where Aux/IAA proteins accumulate. We speculate that the virus disrupts Aux/IAA functions as a means to reprogram the cellular environment of older cells to one that is more compatible for virus replication and spread.

scholarly journals Tobacco mosaic virus-directed reprogramming of auxin/indole acetic acid protein transcriptional responses enhances virus phloem loading

2016 ◽  
Vol 113 (19) ◽  
pp. E2740-E2749 ◽  
Author(s):  
Tamara D. Collum ◽  
Meenu S. Padmanabhan ◽  
Yi-Cheng Hsieh ◽  
James N. Culver
Keyword(s):  
Acetic Acid ◽  
Tobacco Mosaic Virus ◽  
Mosaic Virus ◽  
Nuclear Localization ◽  
Indole Acetic Acid ◽  
Phloem Loading ◽  
Dependent Manner ◽  
Expression Studies ◽  
Systemic Spread ◽  
Regulated Gene Expression

Vascular phloem loading has long been recognized as an essential step in the establishment of a systemic virus infection. In this study, an interaction between the replication protein of tobacco mosaic virus (TMV) and phloem-specific auxin/indole acetic acid (Aux/IAA) transcriptional regulators was found to modulate virus phloem loading in an age-dependent manner. Promoter expression studies show that in mature tissues TMV 126/183-kDa–interacting Aux/IAAs predominantly express and accumulate within the nuclei of phloem companion cells (CCs). Furthermore, CC Aux/IAA nuclear localization is disrupted upon infection with an interacting virus. In situ analysis of virus spread shows that the inability to disrupt Aux/IAA CC nuclear localization correlates with a reduced ability to load into the vascular tissue. Subsequent systemic movement assays also demonstrate that a virus capable of disrupting Aux/IAA localization is significantly more competitive at moving out of older plant tissues than a noninteracting virus. Similarly, CC expression and overaccumulation of a degradation-resistant Aux/IAA-interacting protein was found to inhibit TMV accumulation and phloem loading selectively in flowering plants. Transcriptional expression studies demonstrate a role for Aux/IAA-interacting proteins in the regulation of salicylic and jasmonic acid host defense responses as well as virus-specific movement factors, including pectin methylesterase, that are involved in regulating plasmodesmata size-exclusion limits and promoting virus cell-to-cell movement. Combined, these findings indicate that TMV directs the reprogramming of auxin-regulated gene expression within the vascular phloem of mature tissues as a means to enhance phloem loading and systemic spread.

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.

Degradation of tobacco mosaic virus with acetic acid

Virology ◽  
1957 ◽  
Vol 4 (1) ◽  
pp. 1-4 ◽  
Author(s):  
H. Fraenkel-Conrat
Keyword(s):  
Acetic Acid ◽  
Tobacco Mosaic Virus ◽  
Mosaic Virus

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 ORF6 of Tobacco mosaic virus is a determinant of viral pathogenicity in Nicotiana benthamiana

2004 ◽  
Vol 85 (10) ◽  
pp. 3123-3133 ◽  
Author(s):  
Tomas Canto ◽  
Stuart A. MacFarlane ◽  
Peter Palukaitis
Keyword(s):  
Tobacco Mosaic Virus ◽  
Mosaic Virus ◽  
Nicotiana Benthamiana ◽  
Fluorescent Protein ◽  
Tobacco Rattle Virus ◽  
Potato Virus X ◽  
Host Responses ◽  
Reading Frame ◽  
Virus Accumulation ◽  
Green Fluorescent

Tobacco mosaic virus (TMV) contains a sixth open reading frame (ORF6) that potentially encodes a 4·8 kDa protein. Elimination of ORF6 from TMV attenuated host responses in Nicotiana benthamiana without alteration in virus accumulation. Furthermore, heterologous expression of TMV ORF6 from either potato virus X (PVX) or tobacco rattle virus (TRV) vectors enhanced the virulence of both viruses in N. benthamiana, also without effects on their accumulation. By contrast, the presence or absence of TMV ORF6 had no effect on host response or virus accumulation in N. tabacum plants infected with TMV or PVX. TMV ORF6 also had no effect on the synergism between TMV and PVX in N. tabacum. However, the presence of the TMV ORF6 did have an effect on the pathogenicity of a TRV vector in N. tabacum. In three different types of assay carried out in N. benthamiana plants, expression of TMV ORF6 failed to suppress gene silencing. Expression in N. benthamiana epidermal cells of the encoded 4·8 kDa protein fused to the green fluorescent protein at either end showed, in addition to widespread cytosolic fluorescence, plasmodesmatal targeting specific to both fusion constructs. The role of the ORF6 in host responses is discussed.

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