Single amino acid changes in the turnip mosaic virus viral genome-linked protein (VPg) confer virulence towards Arabidopsis thaliana mutants knocked out for eukaryotic initiation factors eIF(iso)4E and eIF(iso)4G

AbstractTurnip mosaic virus (TuMV), belonging to the genus Potyvirus (family Potyviridae), has a large host range and consists of a single-stranded positive sense RNA genome encoding 12 proteins, including the P1 protease. This protein which is separated from the polyprotein by cis cleavage at its respective C-terminus, has been attributed with different functions during potyviral infection of plants. P1 of Turnip mosaic virus (P1-TuMV) harbors an FGSF-motif and FGSL-motif at its N-terminus. This motif is predicted to be a binding site for the host Ras GTPase-activating protein-binding protein (G3BP), which is a key factor for stress granule (SG) formation in mammalian systems and often targeted by viruses to inhibit SG formation. We therefore hypothesized that P1-TuMV might interact with G3BP to control and regulate plant SGs to optimize cellular conditions for the production of viral proteins. Here, we analyzed the co-localization of the Arabidopsis thaliana G3BP-2 with the P1 of two TuMV isolates, namely UK 1 and DEU 2. Surprisingly, P1-TuMV-DEU 2 co-localized with AtG3BP-2 under abiotic stress conditions, whereas P1-TuMV-UK 1 did not. AtG3BP-2::RFP showed strong SGs formation after stress, while P1-UK 1::eGFP maintained a chloroplastic signal under stress conditions, the signal of P1-DEU 2::eGFP co-localized with that of AtG3BP-2::RFP. This indicates a specific interaction between P1-DEU 2 and the AtG3BP family which is not solely based on the canonical interaction motifs.

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Monoclonal Antibodies Detect a Single Amino Acid Difference Between the Coat Proteins of Soilborne Wheat Mosaic Virus Isolates: Implications for Virus Structure

Phytopathology ◽

10.1094/phyto.1997.87.3.295 ◽

1997 ◽

Vol 87 (3) ◽

pp. 295-301 ◽

Cited By ~ 19

Author(s):

Jianping Chen ◽

Lesley Torrance ◽

Graham H. Cowan ◽

Stuart A. MacFarlane ◽

Gerald Stubbs ◽

...

Keyword(s):

Amino Acids ◽

Monoclonal Antibodies ◽

Amino Acid ◽

Mosaic Virus ◽

Single Amino Acid ◽

Computer Assisted ◽

Amino Acid Difference ◽

Coat Proteins ◽

C Terminus ◽

Readthrough Protein

Four monoclonal antibodies (MAbs) were prepared against an isolate of soilborne wheat mosaic furovirus from Oklahoma (SBWMV Okl-7). Three MAbs had different reactivities in tests on SBWMV isolates from Nebraska (Lab1), France, and Japan. One MAb (SCR 133) also reacted with oat golden stripe furovirus. None of the MAbs cross-reacted with other rod-shaped viruses including beet necrotic yellow vein furovirus, potato mop-top furovirus, and tobacco rattle tobravirus. Sequence analysis of nucleotides between 334 and 1,000 of RNA 2, the region that encodes the coat protein (CP) and the first 44 amino acids of a readthrough protein, of the four SBWMV isolates revealed up to 27 base changes from the published sequence of a Nebraska field isolate of SBWMV. Most changes were translationally silent, but some caused differences of one to three amino acids in residues located near either the N- or C-terminus of the CPs of the different isolates. Two further single amino acid changes were found at the beginning of the readthrough domain of the CP-readthrough protein. Some of these amino acid changes could be discriminated by MAbs SCR 132, SCR 133, and SCR 134. Peptide scanning (Pepscan) analysis indicated that the epitope recognized by SCR 134 is located near the N-terminus of the CP. SCR 132 was deduced to react with a discontinuous CP epitope near the C-terminus, and SCR 133 reacted with a surface-located continuous epitope also near the C-terminus. Predictions of CP structure from computer-assisted three-dimensional model building, by comparison with the X-ray fiber diffraction structure of tobacco mosaic virus, suggested that the three CP amino acids found to differ between isolates of SBWMV were located near the viral surface and were in regions predicted to be antigenic.

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The 5′ Third of Cauliflower mosaic virus Gene VI Conditions Resistance Breakage in Arabidopsis Ecotype Tsu-0

Phytopathology ◽

10.1094/phyto.2002.92.2.190 ◽

2002 ◽

Vol 92 (2) ◽

pp. 190-196 ◽

Cited By ~ 24

Author(s):

K. Agama ◽

S. Beach ◽

J. Schoelz ◽

S. M. Leisner

Keyword(s):

Arabidopsis Thaliana ◽

Mosaic Virus ◽

Viral Genome ◽

Plant Defenses ◽

Cauliflower Mosaic Virus ◽

Virus Gene ◽

Arabidopsis Ecotype ◽

Passive Mechanism ◽

Different Types ◽

Solanaceous Plants

Arabidopsis thaliana ecotypes vary in their responses to viruses. In this study, we analyzed the variation in response of A. thaliana ecotype Tsu-0 to Cauliflower mosaic virus (CaMV). This ecotype was previously reported to be resistant to two CaMV isolates (CM1841 and CM4-184), but susceptible to W260. In this study, we show that Tsu-0 is resistant to four additional CaMV isolates. CaMV propagated within the rosette leaves of Tsu-0 plants, but did not appear to spread systemically into the inflorescence. However, virus viability in rosette leaves of Tsu-0 plants apparently was not compromised because infectious CaMV could be recovered from these organs. W260 overcomes Tsu-0 resistance by a passive mechanism (i.e., this virus avoids activating plant defenses). The portion of the viral genome responsible for W260 resistance breakage was mapped to the 5′ third of gene VI, which we have termed RBR-1. This region is also responsible for controlling the ability of CaMV to infect different types of solanaceous plants. Hence, the pathways by which plants of different families interact with CaMV may be conserved through evolution.

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Sequence Variations Among 17 New Radish Isolates of Turnip mosaic virus Showing Differential Pathogenicity and Infectivity in Nicotiana benthamiana, Brassica rapa, and Raphanus sativus

Phytopathology ◽

10.1094/phyto-12-17-0401-r ◽

2019 ◽

Vol 109 (5) ◽

pp. 904-912 ◽

Cited By ~ 2

Author(s):

Junsu Gong ◽

Hye-Kyoung Ju ◽

Ik-Hyun Kim ◽

Eun-Young Seo ◽

In-Sook Cho ◽

...

Keyword(s):

Amino Acid ◽

Mosaic Virus ◽

Chinese Cabbage ◽

Nicotiana Benthamiana ◽

Turnip Mosaic Virus ◽

Amino Acid Residues ◽

Systemic Necrosis ◽

Infectious Clones ◽

Sequence Variations ◽

Distinct Sequence

Infectious clones were generated from 17 new Korean radish isolates of Turnip mosaic virus (TuMV). Phylogenetic analysis indicated that all new isolates, and three previously characterized Korean radish isolates, belong to the basal-BR group (indicating that the pathotype can infect both Brassica and Raphanus spp.). Pairwise analysis revealed genomic nucleotide and polyprotein amino acid identities of >87.9 and >95.7%, respectively. Five clones (HJY1, HJY2, KIH2, BE, and prior isolate R007) had lower sequence identities than other isolates and produced mild symptoms in Nicotiana benthamiana. These isolates formed three distinct sequence classes (HJY1/HJY2/R007, KIH2, and BE), and several differential amino acid residues (in P1, P3, 6K2, and VPg) were present only in mild isolates HJY1, HJY2, and R007. The remaining isolates all induced systemic necrosis in N. benthamiana. Four mild isolates formed a phylogenetic subclade separate from another subclade including all of the necrosis-inducing isolates plus mild isolate KIH2. Symptom severity in radish and Chinese cabbage genotypes was not correlated with pathogenicity in N. benthamiana; indeed, Chinese cabbage cultivar Norang was not infected by any isolate, whereas Chinese cabbage cultivar Chusarang was uniformly susceptible. Four isolates were unable to infect radish cultivar Iljin, but no specific amino acid residues were correlated with avirulence. These results may lead to the identification of new resistance genes against TuMV.

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Increased Viral Yield and Symptom Severity Result from a Single Amino Acid Substitution in the Turnip Yellow Mosaic Virus Movement Protein

Molecular Plant-Microbe Interactions ◽

10.1094/mpmi-6-268 ◽

1993 ◽

Vol 6 (3) ◽

pp. 268 ◽

Cited By ~ 10

Author(s):

Ching-Hsiu Tsai

Keyword(s):

Amino Acid ◽

Mosaic Virus ◽

Amino Acid Substitution ◽

Symptom Severity ◽

Movement Protein ◽

Single Amino Acid ◽

Yellow Mosaic Virus ◽

Virus Movement ◽

Turnip Yellow Mosaic Virus ◽

Viral Yield

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The Dual Role of the Potyvirus P3 Protein of Turnip mosaic virus as a Symptom and Avirulence Determinant in Brassicas

Molecular Plant-Microbe Interactions ◽

10.1094/mpmi.2003.16.9.777 ◽

2003 ◽

Vol 16 (9) ◽

pp. 777-784 ◽

Cited By ~ 100

Author(s):

Carol E. Jenner ◽

Xiaowu Wang ◽

Kenta Tomimura ◽

Kazusato Ohshima ◽

Fernando Ponz ◽

...

Keyword(s):

Mosaic Virus ◽

Resistance Genes ◽

Plant Virus ◽

Turnip Mosaic Virus ◽

Single Amino Acid ◽

Infection Cycle ◽

In Planta ◽

Napus Line ◽

The Uk

Two isolates of the potyvirus Turnip mosaic virus (TuMV), UK 1 and CDN 1, differ both in their general symptoms on the susceptible propagation host Brassica juncea and in their ability to infect B. napus lines possessing a variety of dominant resistance genes. The isolate CDN 1 produces a more extreme mosaic in infected brassica leaves than UK 1 and is able to overcome the resistance genes TuRB01, TuRB04, and TuRB05. The resistance gene TuRB03, in the B. napus line 22S, is effective against CDN 1 but not UK 1. The nucleic acid sequences of the UK 1 and CDN 1 isolates were 90% identical. The C-terminal half of the P3 protein was identified as being responsible for the differences in symptoms in B. juncea. A single amino acid in the P3 protein was found to be the avirulence determinant for TuRB03. Previous work already has identified the P3 as an avirulence determinant for TuRB04. Our results increase the understanding of the basis of plant-virus recognition, show the importance of the potyviral P3 gene as a symptom determinant, and provide a role in planta for the poorly understood P3 protein in a normal infection cycle.

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