Serological Identity of Potato Virus X (PVX) and PCR Characterization of Its Coat Protein (CP) Gene

Potato virus X (PVX) is among top ten most economically damaging plant viruses in the world and its increasing incidence is getting an alarming situation in potato crop of Pakistan. During two consecutive years (2010-11 and 2011-12), the incidence of PVX was recorded in potato fields at Rawalpindi, Islamabad, Faisalabad and Sahiwal. The samples were collected and subjected to Double Antibody Sandwiched (DAS) Enzyme Linked Immunosorbant Assay (ELISA) and average incidence of PVX was determined about 16.86% (OD405nm 1.38) during 2010-11 and 27.10% (OD405nm 0.479) in 2011-12. The infectivity of the virus was assayed through mechanical inoculation on Nicotiana tabacum cv. Samsun, N. rustica, Datura stramonium, Chenopodium sp. Gomphrena and Capsicum annuum producing local lesion, mosaic and mottling symptoms. Coat protein (CP) gene specific sense and antisense primer successfully amplified a 750bp fragments through Polymerase Chain Reaction (PCR) assay.

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Peptide display on Potato virus X: molecular features of the coat protein-fused peptide affecting cell-to-cell and phloem movement of chimeric virus particles

Journal of General Virology ◽

10.1099/vir.0.82097-0 ◽

2006 ◽

Vol 87 (10) ◽

pp. 3103-3112 ◽

Cited By ~ 60

Author(s):

Chiara Lico ◽

Floriana Capuano ◽

Giovanni Renzone ◽

Marcello Donini ◽

Carla Marusic ◽

...

Keyword(s):

Coat Protein ◽

Potato Virus ◽

Potato Virus X ◽

Structural Features ◽

Plant Viruses ◽

Chimeric Virus ◽

Expression Vectors ◽

In Planta ◽

Virus Particles ◽

Molecular Features

The potexvirus Potato virus X (PVX) can be modified genetically to generate chimeric virus particles (CVPs) carrying heterologous peptides fused to coat protein (CP) subunits. A spontaneous PVX mutant expressing a truncated, but functional, form of the CP has been isolated. With the aim of exploiting this virus to display peptides useful for vaccine formulations, two novel viral expression vectors based on pPVX201 (bearing the wild-type PVX genome) were constructed encoding the truncated CP. Both vectors were able to produce infectious virus particles in planta and were used to insert a panel of sequences encoding peptides of biopharmaceutical interest as N-terminal fusions to the truncated cp gene. The analysis of infection progression induced by the different constructs enabled identification of two important structural features of the fused peptide, namely tryptophan content and isoelectric point, critically affecting the formation of PVX CVPs and virus movement through the plant. These results are discussed in view of the rising interest in engineered plant viruses for development of peptide-based epitope vaccines.

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Inhibition of RNA silencing by the coat protein of Pelargonium flower break virus: distinctions from closely related suppressors

Journal of General Virology ◽

10.1099/vir.0.006098-0 ◽

2009 ◽

Vol 90 (2) ◽

pp. 519-525 ◽

Cited By ~ 25

Author(s):

Sandra Martínez-Turiño ◽

Carmen Hernández

Keyword(s):

Coat Protein ◽

Potato Virus ◽

Rna Silencing ◽

Potato Virus X ◽

Plant Viruses ◽

Small Interfering Rnas ◽

Silencing Suppression ◽

Viral Suppressors

Viral-derived double-stranded RNAs (dsRNAs) activate RNA silencing, generating small interfering RNAs (siRNAs) which are incorporated into an RNA-induced silencing complex (RISC) that promotes homology-dependent degradation of cognate RNAs. To counteract this, plant viruses express RNA silencing suppressors. Here, we show that the coat protein (CP) of Pelargonium flower break virus (PFBV), a member of the genus Carmovirus, is able to efficiently inhibit RNA silencing. Interestingly, PFBV CP blocked both sense RNA- and dsRNA-triggered RNA silencing and did not preclude generation of siRNAs, which is in contrast with the abilities that have been reported for other carmoviral CPs. We have also found that PFBV CP can bind siRNAs and that this ability correlates with silencing suppression activity and enhancement of potato virus X pathogenicity. Collectively, the results indicate that PFBV CP inhibits RNA silencing by sequestering siRNAs and preventing their incorporation into a RISC, thus behaving similarly to unrelated viral suppressors but dissimilarly to orthologous ones.

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