scholarly journals Genomic Segments RNA1 and RNA2 of Prunus necrotic ringspot virus Codetermine Viral Pathogenicity to Adapt to Alternating Natural Prunus Hosts

2013 ◽  
Vol 26 (5) ◽  
pp. 515-527 ◽  
Author(s):  
Hongguang Cui ◽  
Ni Hong ◽  
Guoping Wang ◽  
Aiming Wang
Keyword(s):  
Fruit Trees ◽  
Fruit Production ◽  
Ringspot Virus ◽  
Site Directed Mutagenesis ◽  
Economic Losses ◽  
Cdna Clones ◽  
Virulence Determinants ◽  
Prunus Necrotic Ringspot Virus ◽  
Terminal Nucleotide Sequence ◽  
Viral Accumulation

Prunus necrotic ringspot virus (PNRSV) affects Prunus fruit production worldwide. To date, numerous PNRSV isolates with diverse pathological properties have been documented. To study the pathogenicity of PNRSV, which directly or indirectly determines the economic losses of infected fruit trees, we have recently sequenced the complete genome of peach isolate Pch12 and cherry isolate Chr3, belonging to the pathogenically aggressive PV32 group and mild PV96 group, respectively. Here, we constructed the Chr3- and Pch12-derived full-length cDNA clones that were infectious in the experimental host cucumber and their respective natural Prunus hosts. Pch12-derived clones induced much more severe symptoms than Chr3 in cucumber, and the pathogenicity discrepancy between Chr3 and Pch12 was associated with virus accumulation. By reassortment of genomic segments, swapping of partial genomic segments, and site-directed mutagenesis, we identified the 3′ terminal nucleotide sequence (1C region) in RNA1 and amino acid K at residue 279 in RNA2-encoded P2 as the severe virulence determinants in Pch12. Gain-of-function experiments demonstrated that both the 1C region and K279 of Pch12 were required for severe virulence and high levels of viral accumulation. Our results suggest that PNRSV RNA1 and RNA2 codetermine viral pathogenicity to adapt to alternating natural Prunus hosts, likely through mediating viral accumulation.

scholarly journals Development of Real-Time RT-PCR Assay for Detection of Prunus necrotic ringspot virus in Fruit Trees

Plant Disease ◽  
2003 ◽  
Vol 87 (11) ◽  
pp. 1344-1348 ◽  
Author(s):  
S. Marbot ◽  
M. Salmon ◽  
M. Vendrame ◽  
A. Huwaert ◽  
J. Kummert ◽  
...  
Keyword(s):  
Real Time ◽  
Fruit Trees ◽  
Minor Groove ◽  
Diagnostic Techniques ◽  
Ringspot Virus ◽  
Covalent Attachment ◽  
Minor Groove Binder ◽  
Rt Pcr ◽  
Pcr Assay ◽  
Prunus Necrotic Ringspot Virus

A real-time fluorescent reverse-transcriptase polymerase chain reaction (RT-PCR) assay using a short fluorogenic 3′ minor groove binder (MGB) DNA hydrolysis probe was developed for the detection of Prunus necrotic ringspot virus (PNRSV) in stone fruit trees. The covalent attachment of the minor groove binder moiety at the 3′ end of the probe increased the probe target duplex stability and raised the melting temperature to a range suitable for real-time analysis. The real-time RT-PCR assay correlated well with conventional RT-PCR results for the detection of PNRSV. This assay reliably detects PNRSV in bark tissues of dormant cherry and plum trees. Furthermore, it is well adapted for the routine detection of PNRSV because it eliminates one risk of contamination by performing the whole test in a single closed tube. This system may replace the commonly used diagnostic techniques (e.g., woody indicators and immunological tests) to detect this virus.

scholarly journals Genomic organization of RNA2 of Tomato ringspot virus: processing at a third cleavage site in the N-terminal region of the polyprotein in vitro

2001 ◽  
Vol 82 (7) ◽  
pp. 1785-1790 ◽  
Author(s):  
Karma Carrier ◽  
Yu Xiang ◽  
Hélène Sanfaçon
Keyword(s):  
Cleavage Site ◽  
Terminal Region ◽  
Ringspot Virus ◽  
Protein Domain ◽  
Site Directed Mutagenesis ◽  
Cdna Clones ◽  
Cleavage Sites ◽  
Tomato Ringspot Virus ◽  
Definition Of

The proteinase of Tomato ringspot virus (genus Nepovirus) is responsible for proteolytic cleavage of the RNA2-encoded polyprotein (P2) at two cleavage sites, allowing definition of the domains for the movement protein (MP) and coat protein. In this study, we have characterized a third cleavage site in the N-terminal region of P2 using an in vitro processing assay and partial cDNA clones. Results from site-directed mutagenesis of putative cleavage sites suggest that cleavage occurs at dipeptide Q301/G. Cleavage at this site is predicted to result in the release of two proteins from the N-terminal region of P2: a 34 kDa protein located at the N terminus of P2 (assuming translation initiation at the first AUG codon) and a 71 kDa protein located immediately upstream of the MP domain. In contrast, only one protein domain is present in the equivalent region of the P2 polyprotein of other characterized nepoviruses.

scholarly journals Porcine Reproductive and Respiratory Syndrome Virus Reverse Genetics and the Major Applications

Viruses ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 1245
Author(s):  
Jayeshbhai Chaudhari ◽  
Hiep L. X. Vu
Keyword(s):  
Viral Genome ◽  
Reverse Genetics ◽  
Rna Virus ◽  
Site Directed Mutagenesis ◽  
Economic Losses ◽  
Respiratory Syndrome Virus ◽  
Cdna Clones ◽  
Swine Industry ◽  
Host Interaction ◽  
Foreign Genes

Porcine reproductive and respiratory syndrome virus (PRRSV) is a positive sense, single-stranded RNA virus that is known to infect only pigs. The virus emerged in the late 1980s and became endemic in most swine producing countries, causing substantial economic losses to the swine industry. The first reverse genetics system for PRRSV was reported in 1998. Since then, several infectious cDNA clones for PRRSV have been constructed. The availability of these infectious cDNA clones has facilitated the genetic modifications of the viral genome at precise locations. Common approaches to manipulate the viral genome include site-directed mutagenesis, deletion of viral genes or gene fragments, insertion of foreign genes, and swapping genes between PRRSV strains or between PRRSV and other members of the Arteriviridae family. In this review, we describe the approaches to construct an infectious cDNA for PRRSV and the ten major applications of these infectious clones to study virus biology and virus–host interaction, and to design a new generation of vaccines with improved levels of safety and efficacy.

scholarly journals Partial characterization of Prunus Necrotic Ringspot Virus on apple in EGYPT 

2021 ◽  
Author(s):  
Aly M. Abdel-Salam ◽  
Samah A. Mokbel
Keyword(s):  
Binding Assay ◽  
Ringspot Virus ◽  
Economic Losses ◽  
Rt Pcr ◽  
Chain Reaction ◽  
Prunus Necrotic Ringspot Virus ◽  
Polymerase Chain ◽  
Severe Isolate ◽  
Microscopy Examination

Abstract A severe isolate of Prunus necrotic ringspot virus (PNRSV) was isolated from apple orchards in the vicinity of Nubaria city, Beheira governorate, Egypt. Infected-apple trees showed chlorotic, necrotic ringspots, and shoot holes on leaves. Severely infected- trees withered, became useless, and were removed causing severe economic losses. Reverse transcriptase (RT) polymerase chain reaction (PCR), RT-PCR, using degenerate primer pair for the coat protein (CP) gene of Ilarvirus amplified products similar to those produced from peach and apricot isolates of PNRSV-infecting stone fruits). Dot blotting immuno-binding assay (DBIA showed a positive reaction between PNRSV-infected apple sap and an Egyptian antiserum for PNRSV. Purified preparation from infected leaves, using the electro-elution technique yielded nucleoprotein, which had Amax and Amin at 260 and 240 nm respectively. Electron microscopy examination showed spherical virions with ca. 26 nm in diameter.

scholarly journals Seasonal occurrence of the Mediterranean fruit fly, Ceratitis capitata (Wiedemann, 1824) (Diptera: Tephritidae) in southern Syria

2016 ◽  
Vol 85 (3) ◽  
pp. 311-323 ◽  
Author(s):  
Mohammed Mansour ◽  
Fater Mohamad
Keyword(s):  
Ceratitis Capitata ◽  
Fruit Fly ◽  
Fruit Trees ◽  
Fruit Production ◽  
Small Population ◽  
Mediterranean Fruit Fly ◽  
Diospyros Kaki ◽  
Population Fluctuations ◽  
Sampling Studies ◽  
The Mediterranean

Abstract Population fluctuations of the Mediterranean fruit fly (medfly), Ceratitis capitata, were investigated between 1999 and 2001 at several locations representing fruit production areas in the southern part of Syria (Damascus Ghota, Zabadani, Sargaiah, Rankus, Orneh and Ain Al-Arab). Medfly adults were monitored weekly all year around using Jackson traps baited with trimedlure dispensers. Larvae were also sampled in Damascus Ghota by collecting fruits from ripe or ripening fruit trees and recording the number of larvae emerged from these fruits. In addition, suspected overwintering refuges were sampled at weekly intervals during the three coldest months of the year (December – February) and the number of collected larvae was recorded. The results of trap catches and fruit sampling studies showed a similar pattern of occurrence of medfly populations in the study areas, particularly in Damascus Ghota, during the three years of the study. In Damascus Ghota, flies were caught continuously from early June to late December with some variability between years. Two distinct periods of high fly activity were observed: the first one occurred in August and the second in November with a much higher amplitude. In general, seasonal fluctuations in the pattern of occurrence were influenced by differences in temperature and abundance of preferred host fruits. Traps on fig Ficus carica and oriental persimmon Diospyros kaki trees caught the highest numbers of flies, and fruits collected from these trees showed the highest level of infestation, reaching 100% for fig fruit late in the season. Sampling fruits (in Damascus Ghota) from trees during the three coldest months of the year showed that a small population of medfly larvae was able to survive winter conditions in prickly pear Opuntia vulgaris fruit left on the trees. In the other areas of the study (Zabadani, Sargaiah, Rankus, Orneh and Ain Al-Arab), only a few flies were caught.

scholarly journals Molecular characterization of Prunus necrotic ringspot virus isolated from rose in Brazil

2015 ◽  
Vol 45 (12) ◽  
pp. 2197-2200 ◽  
Author(s):  
Thor Vinícius Martins Fajardo ◽  
Monique Bezerra Nascimento ◽  
Marcelo Eiras ◽  
Osmar Nickel ◽  
Gilvan Pio-Ribeiro
Keyword(s):  
Amino Acid ◽  
Molecular Characterization ◽  
Molecular Analysis ◽  
Nucleotide Sequences ◽  
Amino Acid Sequences ◽  
Causal Agent ◽  
Ringspot Virus ◽  
Prunus Necrotic Ringspot Virus ◽  
First Time

ABSTRACT: There is no molecular characterization of Brazilian isolates of Prunus necrotic ringspot virus (PNRSV), except for those infecting peach. In this research, the causal agent of rose mosaic was determined and the movement (MP) and coat (CP) protein genes of a PNRSV isolate from rose were molecularly characterized for the first time in Brazil. The nucleotide and deduced amino acid sequences of MP and CP complete genes were aligned and compared with other isolates. Molecular analysis of the MP and CP nucleotide sequences of a Brazilian PNRSV isolate from rose and others from this same host showed highest identities of 96.7% and 98.6%, respectively, and Rose-Br isolate was classified in PV32 group.

scholarly journals The Expression Level of the 3a Movement Protein Determines Differences in Severity of Symptoms Between Two Strains of Tomato Aspermy Cucumovirus

1997 ◽  
Vol 10 (2) ◽  
pp. 171-179 ◽  
Author(s):  
Ignacio M. Moreno ◽  
Juan José Bernal ◽  
Blanca García de Blas ◽  
Emilio Rodriguez-Cerezo ◽  
Fernando García-Arenal
Keyword(s):  
Movement Protein ◽  
Stop Codon ◽  
Site Directed Mutagenesis ◽  
In Vitro Translation ◽  
Protein Accumulation ◽  
Cdna Clones ◽  
Post Inoculation ◽  
Mild Phenotype ◽  
Systemic Leaf ◽  
Chlorotic Mottle

Two strains of tomato aspermy cucumovirus, 1-TAV and V-TAV, differ in the severity of the symptoms induced in Nicotiana tabacum: 1-TAV induces a severe chlorotic mottle that appears 5 days post inoculation (d.p.i.) in the second systemic leaf, while V-TAV-infected plants show a mild chlorotic mottle, unevenly distributed in the leaf lamina, that appears 7 d.p.i. in the third or fourth systemic leaf. The manipulation of full-length cDNA clones giving infectious transcripts of V-TAV RNAs 1, 2, and 3 and 1-TAV RNA 3 revealed that the slow, mild phenotype of V-TAV maps to the movement protein (MP) gene. By site-directed mutagenesis it was further shown that this phenotype co-segregates with a single nucleotide substitution that introduces an in-frame UAA stop codon at the fourth position of the MP open reading frame of V-TAV. The presence of this stop codon results in a diminished expression of the MP in both tobacco protoplasts and leaves. Analyses of the progress of infection and of the time course of MP and coat protein accumulation show that the low level of MP in V-TAV-infected leaves limits the rate of cell-to-cell movement and leads to the mild phenotype. Data from the infectivity of RNA 3 transcripts with or without this stop codon, plus data from in vitro translation of virion or transcript RNA 3, suggest that the small amount of MP observed in V-TAV-infected leaves is expressed from a minor RNA 3 subpopulation lacking the stop codon.

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