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differential identification of three species of curtovirus using loop-mediated isothermal amplification.rapid and sensitive detection methods for three species of curtovirus were developed using a loop-mediated isothermal amplification (lamp) technique. a universal primer set for detecting the three main species of curtovirus at the same time, and three kinds of species-specific primer sets were designed and used for lamp reactions. results from the lamp reactions were visualized both by color changes after adding sybr green i staining dye and by dna laddering on agarose gel electrophoresis. the o ...201424957721
interaction patterns between potato virus y and eif4e-mediated recessive resistance in the solanaceae.the structural pattern of infectivity matrices, which contains infection data resulting from inoculations of a set of hosts by a set of parasites, is a key parameter for our understanding of biological interactions and their evolution. this pattern determines the evolution of parasite pathogenicity and host resistance, the spatiotemporal distribution of host and parasite genotypes, and the efficiency of disease control strategies. two major patterns have been proposed for plant-virus genotype in ...201424942572
surface plasmon resonance for monitoring the interaction of potato virus y with monoclonal antibodies.surface plasmon resonance (spr)-based biosensors have been widely utilized for measuring interactions of a variety of molecules. fewer examples include higher biological entities such as bacteria and viruses, and even fewer deal with plant viruses. here, we describe the optimization of an spr sensor chip for evaluation of the interaction of the economically relevant filamentous potato virus y (pvy) with monoclonal antibodies. different virus isolates were efficiently and stably bound to a previo ...201424220292
virus strains differentially induce plant susceptibility to aphid vectors and chewing herbivores.plants are frequently attacked by both pathogens and insects, and an attack from one can induce plant responses that affect resistance to the other. however, we currently lack a predictive framework for understanding how pathogens, their vectors, and other herbivores interact. to address this gap, we have investigated the effects of a viral infection in the host plant on both its aphid vector and non-vector herbivores. we tested whether the infection by three different strains of potato virus y ...201424178835
ny-1 and ny-2 genes conferring hypersensitive response to potato virus y (pvy) in cultivated potatoes: mapping and marker-assisted selection validation for pvy resistance in potato breeding.potato virus y (pvy) is one of the most important viruses affecting potato (solanum tuberosum) production. in this study, a novel hypersensitive response (hr) gene, ny-2, conferring resistance to pvy was mapped on potato chromosome xi in cultivar romula. in cultivars albatros and sekwana, the ny-1 gene was mapped on chromosome ix. in cv. romula, the local lesions appeared in leaves inoculated with the pvy(n-wi) isolate at 20 and 28 °c; pvy systemic infections were only occasionally observed at t ...201424860254
interactions among potato genotypes, growth stages, virus strains, and inoculation methods in the potato virus y and green peach aphid pathosystem.potato virus y (pvy) is an economically important and reemerging potato pathogen in north america. pvy infection reduces yield, and some necrotic and recombinant strains render tubers unmarketable. although pvy(o) is the most prevalent strain in the united states, the necrotic and recombinant strains pvy(ntn) and pvy(n:o) are becoming more widespread. infection rates in aphid-inoculated (myzus persicae (sulzer)) and mechanically inoculated plants were compared across two potato genotypes ('yukon ...201424690278
analysis of potato virus y coat protein epitopes recognized by three commercial monoclonal antibodies.potato virus y (pvy, genus potyvirus) causes substantial economic losses in solanaceous plants. routine screening for pvy is an essential part of seed potato certification, and serological assays are often used. the commercial, commonly used monoclonal antibodies, mab1128, mab1129, and mab1130, recognize the viral coat protein (cp) of pvy and distinguish pvyn strains from pvyo and pvyc strains, or detect all pvy strains, respectively. however, the minimal epitopes recognized by these antibodies ...201425542005
potato virus y infection hinders potato defence response and renders plants more vulnerable to colorado potato beetle attack.in the field, plants are challenged by more than one biotic stressor at the same time. in this study, the molecular interactions between potato (solanum tuberosum l.), colorado potato beetle (leptinotarsa decemlineata say; cpb) and potato virus y(ntn) (pvy(ntn) ) were investigated through analyses of gene expression in the potato leaves and the gut of the cpb larvae, and of the release of potato volatile compounds. cpb larval growth was enhanced when reared on secondary pvy(ntn) -infected plants ...201425251011
salicylic acid is an indispensable component of the ny-1 resistance-gene-mediated response against potato virus y infection in potato.the purpose of the study was to investigate the role of salicylic acid (sa) signalling in ny-1-mediated hypersensitive resistance (hr) of potato (solanum tuberosum l.) to potato virus y (pvy). the responses of the ny-1 allele in the rywal potato cultivar and transgenic nahg-rywal potato plants that do not accumulate sa were characterized at the cytological, biochemical, transcriptome, and proteome levels. analysis of noninoculated and inoculated leaves revealed that hr lesions started to develop ...201424420577
molecular and biological characterization of a recombinant isolate of potato virus y from mexico.an isolate of potato virus y (pvy), pvy-m3, was subjected to biological characterization on potato indicators and to whole-genome sequencing. pvy-m3 induced a local and systemic hypersensitive resistance (hr) response in potato cultivar maris bard expressing the nz gene while inducing no hr in potato cultivars desiree and king edward, carrying ny and nc genes, respectively. these hr responses, combined with a lack of vein necrosis in tobacco, clearly defined pvy-m3 as an isolate of the pvy(z) st ...201424402633
evolution of plant eukaryotic initiation factor 4e (eif4e) and potyvirus genome-linked protein (vpg): a game of mirrors impacting resistance spectrum and durability.polymorphism in the plant eukaryotic translation initiation factor 4e (eif4e) and potyvirus genome-linked protein (vpg) determine, in many cases, the outcome of the confrontation between these two organisms: compatibility (i.e. infection of the plant by the virus) or incompatibility (i.e. resistance of the plant to the virus). the two interacting proteins eif4e and vpg show strikingly similar evolution patterns. most codon positions in their coding sequences are highly constrained for nonsynonym ...201424309680
full-genome analyses of a potato virus y (pvy) isolate infecting pepper (capsicum annuum l.) in the republic of south africa.potato virus y (pvy) is a pathogen of economic importance in pepper and other major crop species in the family solanaceae. three major pvy strain groups: o, c, and n, have been distinguished on the basis of genome sequencing. in this study, the first full-genome sequence of a pvy isolate (jvw-186) infecting pepper from the province of kwazulu-natal, republic of south africa is reported. the complete genome sequence of jvw-186 was assembled from overlapping rt-pcr clones using mega 5 software. tw ...201425303962
molecular characterization of indian isolate of peanut mottle virus and immunodiagnosis using bacterial expressed core capsid protein.peanut mottle virus (pemov), a seed borne potyvirus was recorded in india in 1978, however the virus was not characterized at molecular level. in the present study, an isolate of pemov infecting peanut in southern india was characterized based on host reactions and coat protein (cp) gene sequence, which revealed that the indian isolate was very close to a peanut isolate reported from israel and distinct from pea isolate reported from usa. the core region of cp gene that contained majority of the ...201425674600
expression of symptoms, viral coat protein and silencing suppressor gene during mixed infection of a n-wi strain of potato virus y and an asymptomatic strain of potato virus x.potato virus y (pvy) and potato virus x (pvx), the rna viruses of two different genera results into synergistic interactions on mixed infection. in this study, a n-wi strain of pvy and a pvx strain that is asymptomatic on potato were used to study their interactions during mixed infection in nicotiana benthamiana and nicotiana tabacum with reference to symptom expression, level of coat protein (cp) using elisa and suppressor gene using real time pcr under high temperature (26-40 °c) and low temp ...201425674598
stremorin1.3 hampers potato virus x tgbp1 ability to increase plasmodesmata permeability, but does not interfere with its silencing suppressor activity.the triple gene block 1 (tgbp1) protein encoded by the potato virus x is a multifunctional protein that acts as a suppressor of rna silencing or facilitates the passage of virus from cell to cell by promoting the plasmodesmata opening. we previously showed that the membrane raft protein stremorin1.3 is able to impair pvx infection. here, we show that overexpressed stremorin1.3 does not impair the silencing suppressor activity of tgbp1, but affects its ability to increase plasmodesmata permeabili ...201424657438
survival and transmission of potato virus y, pepino mosaic virus, and potato spindle tuber viroid in water.hydroponic systems and intensive irrigation are used widely in horticulture and thus have the potential for rapid spread of water-transmissible plant pathogens. numerous plant viruses have been reported to occur in aqueous environments, although information on their survival and transmission is minimal, due mainly to the lack of effective detection methods and to the complexity of the required transmission experiments. we have assessed the role of water as a source of plant infection using three ...201424334672
detection of multiple potato viruses in the field suggests synergistic interactions among potato viruses in pakistan.viral diseases have been a major limiting factor threating sustainable potato (solanum tuberosum l.) production in pakistan. surveys were conducted to serologically quantify the incidence of rna viruses infecting potato; potato virus x (pvx), potato virus y (pvy), potato virus s (pvs), potato virus a (pva), potato virus m (pvm) and potato leaf roll virus (plrv) in two major potato cultivars (desiree and cardinal). the results suggest the prevalence of multiple viruses in all surveyed areas with ...201425506305
robust rna silencing-mediated resistance to plum pox virus under variable abiotic and biotic conditions.some abiotic and biotic conditions are known to have a negative impact on post-transcriptional gene silencing (ptgs), thus representing a potential concern for the production of stable engineered virus resistance traits. however, depending on the strategy followed to achieve ptgs of the transgene, different responses to external conditions can be expected. in the present study, we utilized the nicotiana benthamiana–plum pox virus (ppv) pathosystem to evaluate in detail the stability of intron-ha ...201425346969
interference with jasmonic acid-regulated gene expression is a general property of viral suppressors of rna silencing but only partly explains virus-induced changes in plant-aphid interactions.the cucumber mosaic virus (cmv) 2b viral suppressor of rna silencing (vsr) inhibits host responses to jasmonic acid (ja), a chemical signal regulating resistance to insects. previous experiments with a cmv subgroup ia strain and its 2b gene deletion mutant suggested that vsrs might neutralize aphid (myzus persicae) resistance by inhibiting ja-regulated gene expression. to further investigate this, we examined ja-regulated gene expression and aphid performance in nicotiana benthamiana infected wi ...201424362960
involvement of potato (solanum tuberosum l.) mkk6 in response to potato virus y.mitogen-activated protein kinase (mapk) cascades have crucial roles in the regulation of plant development and in plant responses to stress. plant recognition of pathogen-associated molecular patterns or pathogen-derived effector proteins has been shown to trigger activation of several mapks. this then controls defence responses, including synthesis and/or signalling of defence hormones and activation of defence related genes. the mapk cascade genes are highly complex and interconnected, and thu ...201425111695
a procedure for the transient expression of genes by agroinfiltration above the permissive threshold to study temperature-sensitive processes in plant-pathogen interactions.localized expression of genes in plants from t-dnas delivered into plant cells by agrobacterium tumefaciens is an important tool in plant research. the technique, known as agroinfiltration, provides fast, efficient ways to transiently express or silence a desired gene without resorting to the time-consuming, challenging stable transformation of the host, the use of less efficient means of delivery, such as bombardment, or the use of viral vectors, which multiply and spread within the host causin ...201424581046
β-1,3-glucanase class iii promotes spread of pvy(ntn) and improves in planta protein production.glucanases are enzymes regulating the size exclusion limit and permeability of plasmodesmata and play a role in biotic stress. in plant genomes, they are encoded as relatively large gene families divided into four classes. most studies of plant virus interactions have focused on glucanases from classes i and ii. in our study, we have evaluated the role of the β-1,3-glucanase class iii (glu-iii) gene in the potato-potato virus y(ntn) (pvy(ntn)) interaction and implemented the findings to plant bi ...201324273610
resistance breaking tomato spotted wilt virus isolates on resistant pepper varieties in italy.in spring 2012, resistance breaking (rb) isolates of tomato spotted wilt virus (tswv) that overcome the resistance conferred by the tsw gene in different pepper hybrids have been recovered in different locations in southern italy (campania and apulia regions) in protected cultivation, about one month after transplant. the percentage of symptomatic plants was 5-10% and, only in particular cases of advanced stage of cultivation, it reached 30-50% at the end of cycle. all tswv isolates induced simi ...201325151838
genetic compositions of broad bean wilt virus 2 infecting red pepper in korea.the incidence of broad bean wilt virus 2 (bbwv2) on red pepper was investigated using the samples obtained from 24 areas of 8 provinces in korea. two hundred and five samples (79%) out of 260 collected samples were found to be infected with bbwv2. while the single infection rate of bbwv2 was 21.5%, the co-infection rate of bbwv2 with cucumber mosaic virus, pepper mottle virus, pepper mild mottle virus and/or potato virus y was 78.5%. to characterize the genetic diversity of bbwv2 korean isolates ...201325288954
oxylipin biosynthesis genes positively regulate programmed cell death during compatible infections with the synergistic pair potato virus x-potato virus y and tomato spotted wilt virus.one of the most severe symptoms caused by compatible plant-virus interactions is systemic necrosis, which shares common attributes with the hypersensitive response to incompatible pathogens. although several studies have identified viral symptom determinants responsible for systemic necrosis, mechanistic models of how they contribute to necrosis in infected plants remain scarce. here, we examined the involvement of different branches of the oxylipin biosynthesis pathway in the systemic necrosis ...201323487466
root-specific role for nicotiana benthamiana rdr6 in the inhibition of chinese wheat mosaic virus accumulation at higher temperatures.some viruses only infect plants at cool temperatures but the molecular mechanism underlying this low-temperature dependence remains unclear. chinese wheat mosaic virus (cwmv, genus furovirus) was able to infect wheat and nicotiana benthamiana plants at 16 but not at 24°c. when cwmv-infected plants were transferred to 24°c for 2 weeks, the newly emerged leaves and roots became virus free. co-infection with potato virus y rescued cwmv accumulation in n. benthamiana plants after a temperature shift ...201323777430
high prevalence of poleroviruses in field-grown pepper in turkey and tunisia.open-field pepper crops were sampled in 2011 in turkey and tunisia and surveyed for the major pepper-infecting viruses. as expected, potato virus y and cucumber mosaic virus (in both countries), and tobacco etch virus (in turkey only) were quite frequent. however, poleroviruses were the most common viruses, with prevalences above 70 %. partial sequence analyses revealed the occurrence of poleroviruses resembling either beet western yellows virus (bwyv) or pepper vein yellows virus in the sampled ...201323183831
engineered resistance in potato against potato leafroll virus, potato virus a and potato virus y.transgenic potato plants of solanum tuberosum cultivar vales sovereign were generated that expressed fused, tandem, 200 bp segments derived from the capsid protein coding sequences of potato virus y (pvy strain o) and potato leafroll virus (plrv), as well as the cylindrical inclusion body coding sequences of potato virus a (pva), as inverted repeat double-stranded rnas, separated by an intron. the orientation of the expressed double-stranded rnas was either sense-intron-antisense or antisense-in ...201323526159
mutation of a short variable region in hcpro protein of potato virus a affects interactions with a microtubule-associated protein and induces necrotic responses in tobacco.helper component proteinase (hcpro) is a multifunctional protein of potyviruses (genus potyvirus). hcpro of potato virus a (pva) interacts with the microtubule-associated protein hip2 in host cells, and depletion of hip2 reduces virus accumulation. this study shows that hcpro of potato virus y and tobacco etch virus also interact with hip2. the c-proximal portion of pva hcpro determines the interaction with hip2 and was found to contain a stretch of six residues comprising a highly variable regi ...201323514111
[properties of potato virus m and potato virus y isolates in ukraine].monitoring of viruses of tomato plants (lycopersicon esculentum mill.) was carried out. twenty-seven varieties of tomatoes from different regions of ukraine were tested for the virus presence. new symptoms, which had not been described before, were revealed. it was found out that the diseases were caused by potato virus m and potato virus y. this is the first report about the infection of tomato plants with such viruses in ukraine. some biological, physical and chemical properties of the pathoge ...201323720969
seasonal phenology and species composition of the aphid fauna in a northern crop production area.the species diversity of aphids and seasonal timing of their flight activity can have significant impacts on crop production, as aphid species differ in their ability to transmit plant viruses and flight timing affects virus epidemiology. the aim of the study was to characterise the species composition and phenology of aphid fauna in finland in one of the northernmost intensive crop production areas of the world (latitude 64°).201323967149
continuous and emerging challenges of potato virus y in potato.potato virus y (pvy) is one of the oldest known plant viruses, and yet in the past 20 years it emerged in the united states as a relatively new and very serious problem in potato. the virus exists as a complex of strains that induce a wide variety of foliar and tuber symptoms in potato, leading to yield reduction and loss of tuber quality. pvy has displayed a distinct ability to evolve through accumulation of mutations and more rapidly through recombination between different strains, adapting to ...201323915135
effects of the crinivirus coat protein-interacting plant protein sahh on post-transcriptional rna silencing and its suppression.in plants, post-transcriptional gene silencing (ptgs) is a sequence-specific mechanism of rna degradation induced by double-stranded rna (dsrna), which is processed into small interfering rnas (sirnas). sirnas are methylated and, thereby, stabilized by the activity of the s-adenosylmethionine-dependent rna methyltransferase hen1. ptgs is amplified by host-encoded rna-dependent rna polymerases (rdr), which generate dsrna that is processed into secondary sirnas. to counteract this rna silencing-me ...201323697374
potato virus y: a major crop pathogen that has provided major insights into the evolution of viral pathogenicity.potato virus y (pvy) is the type member of the genus potyvirus in the family potyviridae. virion and genome properties: pvy virions have a filamentous, flexuous form, with a length of 730 nm and a diameter of 12 nm. the genomic rna is single stranded, messenger sense, with a length of 9.7 kb, covalently linked to a viral-encoded protein (vpg) at the 5' end and to a 3' polyadenylated tail. the genome is expressed as a polyprotein of approximately 3062 amino acid residues, processed by three virus ...201323480826
fast purification of the filamentous potato virus y using monolithic chromatographic supports.obtaining pure virus suspensions is an essential step in many applications, such as vaccine production, antibody production, sample preparation for procedures requiring enrichment in viruses and other in vitro characterizations. purification procedures usually consist of complex, long lasting and tedious protocols involving several ultracentrifugation steps. such complexity is particularly evident in the case of plant viruses, where the virus needs to be isolated from the complex plant tissue ma ...201323253119
development of multiplex real-time pcr for simultaneous detection of three potyviruses in tobacco plants.to develop a multiplex real-time pcr assay using taqman probes for the simultaneous detection and quantification of tobacco etch virus (tev), potato virus y (pvy) and tobacco vein banding mosaic virus (tvbmv).201323164070
intrahost mechanisms governing emergence of resistance-breaking variants of potato virus y.the emergence of resistance breaking (rb) variants starting from the avirulent potato virus y nn strain (pvy(nn)) was analyzed after imposing different selective host constraints. tobacco resistance to pvy(nn) is conferred by va in both nc745 and vam genotypes, but vam carries an extra resistance gene, va2. rb-variants emerged only in nc745 and unexpectedly accumulated higher in the original host, tobacco b21, than the parental pvy(nn). however, the recovery of rb-variants was interfered by pvy( ...201323332684
intra-specific variability and biological relevance of p3n-pipo protein length in potyviruses.pipo was recently described as a new orf encoded within the genome of the potyviridae family members (pnas 105:5897-5902, 2008). it is embedded within the p3 cistron and is translated in the +2 reading frame relative to the potyviral long orf as the p3n-pipo fusion protein. in this work, we first collected pipo nucleotide sequences available for different isolates of 48 potyvirus species. second, to determine the biological implications of variation in pipo length, we measured infectivity, viral ...201324225158
[sequence variation and protein structure of pipo gene in potato virus y].the objectives of this study were to understand the sequence variation and the putative protein structure of pipo gene in the potato virus y (pvy) collected from solanum tuberosum. the pipo gene in pvy was cloned using a pair of degenerate primers designed from its conserved region and its sequences were used to re-construct phylogenetic tree in potyvirus genera by a bayesian inference method. an expected fragment of 235 bp was amplified in all 20 samples by rt-pcr and the pipo genes in the 20 s ...201324400487
genetic determinants of potato virus y required to overcome or trigger hypersensitive resistance to pvy strain group o controlled by the gene ny in potato.potato virus y (pvy) (genus potyvirus) is the most economically damaging and widely distributed virus in potato. spread of pvy in the field is controlled by growing resistant cultivars. the dominant potato gene ny(tbr) for hypersensitive resistance (hr) controls ordinary pvy strains (pvy(o)) but is overcome by pvy(n) strains. studies with infectious pvy chimeras and mutants indicated that the viral determinants necessary and sufficient to overcome ny(tbr) reside within the helper component prote ...201323113714
farther, slower, stronger: how the plant genetic background protects a major resistance gene from breakdown.genetic resistance provides efficient control of crop diseases, but is limited by pathogen evolution capacities which often result in resistance breakdown. it has been demonstrated recently, in three different pathosystems, that polygenic resistances combining a major-effect gene and quantitative resistance controlled by the genetic background are more durable than monogenic resistances (with the same major gene in a susceptible genetic background), but the underlying mechanisms are unknown. usi ...201323046402
the influence of cis-acting p1 protein and translational elements on the expression of potato virus y helper-component proteinase (hcpro) in heterologous systems and its suppression of silencing activity.in the potyvirus genus, the p1 protein is the first n-terminal product processed from the viral polyprotein, followed by the helper-component proteinase (hcpro). in silencing suppression patch assays, we found that potato virus y (pvy) hcpro expressed from a p1-hcpro sequence increased the accumulation of a reporter gene, whereas protein expressed from an hcpro sequence did not, even with p1 supplied in trans. this enhancing effect of p1 has been noted in other potyviruses, but has remained unex ...201323451733
assessment of snapshot and single step rt-qpcr methods for discriminating potato virus y (pvy) subgroups.potato virus y (pvy) is the most important virus infecting potato (solanum tuberosum), causing potato tuber necrotic ringspot disease (ptnrd), with a great impact on seed potato production. numerous pvy strain groups with different pathogenicity and economical impact are distributed worldwide. tools for accurate and reliable detection and discrimination of pvy strain groups are therefore essential for successful disease management. two state of the art characterization tools based on detecting m ...201323396125
identification of new potato virus y (pvy) molecular determinants for the induction of vein necrosis in tobacco.two tobacco vein necrosis (tvn) determinants, the residues k(400) and e(419) , have been identified previously in the helper component-protease (hc-pro) protein sequence of potato virus y (pvy). however, since their description, non-necrotic pvy isolates with both k(400) and e(419) necrotic determinants have been reported in the literature. this suggests the presence in the viral genome of other, as yet uncharacterized, tvn determinant(s). the identification of pvy(n) pathogenicity determinants ...201222537230
modelling the evolutionary dynamics of viruses within their hosts: a case study using high-throughput sequencing.uncovering how natural selection and genetic drift shape the evolutionary dynamics of virus populations within their hosts can pave the way to a better understanding of virus emergence. mathematical models already play a leading role in these studies and are intended to predict future emergences. here, using high-throughput sequencing, we analyzed the within-host population dynamics of four potato virus y (pvy) variants differing at most by two substitutions involved in pathogenicity properties. ...201222532800
virus adaptation to quantitative plant resistance: erosion or breakdown?adaptation of populations to new environments is frequently costly due to trade-offs between life history traits, and consequently, parasites are expected to be locally adapted to sympatric hosts. also, during adaptation to the host, an increase in parasite fitness could have direct consequences on its aggressiveness (i.e. the quantity of damages caused to the host by the virus). these two phenomena have been observed in the context of pathogen adaptation to host's qualitative and monogenic resi ...201222947055
cytopathological potato virus y structures during solanaceous plants infection.the ultrastructural analysis of tobacco, potato and pepper tissues during infection with necrotic strains and the ordinary potato virus y strain of revealed the presence of virus inclusions not only in the epidermis and mesophyll but also in the vascular tissues. for the first time cytoplasmic inclusions were documented in companion cells and phloem parenchyma as well as in xylem tracheary elements. the ultrastructural features studied in this work consisted of mostly laminated inclusions (in th ...201222410276
purification, crystallization and preliminary x-ray diffraction analysis of the hsp40 protein cpip1 from nicotiana tabacum.chaperones promote many different molecular processes, including the folding, targeting and degradation of proteins. the best-studied chaperone system consists of the hsp70s and their co-chaperones the hsp40s. chaperone function can be hijacked by viruses in plants. potato virus y interacts via its coat protein with an hsp40 from nicotiana tabacum, referred to as ntcpip1, in order to regulate replication. to understand the molecular determinants of this mechanism, different variants of ntcpip1 w ...201222298008
molecular evolution and phylogeography of potato virus y based on the cp gene.potato virus y (pvy) is an important plant pathogen with a wide host range that includes, among others, potato, tobacco, tomato and pepper. the coat protein (cp) of pvy has been commonly used in phylogenetic studies for strain classification. in this study, we used a pool of 292 cp sequences from isolates collected worldwide. after detecting and removing recombinant sequences, we applied bayesian techniques to study the influence of geography and host species in cp population structure and dynam ...201222837421
strain specificity and simultaneous transmission of closely related strains of a potyvirus by myzus persicae.potato virus y (pvy), a potyvirus, is transmitted by aphids in a nonpersistent manner. pvy severely affects potato production worldwide. single and mixed infections of pvy strains, namely pvy(o), pvy(ntn), and pvy(n:o) are a common occurrence in potato systems. however, information available on the ability of aphids to simultaneously transmit multiple pvy strains, specificity associated with simultaneous transmission, and factors affecting specificity are limited. aphid-mediated transmission exp ...201222812113
phylogeography and molecular evolution of potato virus y.potato virus y (pvy) is an important plant pathogen, whose host range includes economically important crops such as potato, tobacco, tomato, and pepper. pvy presents three main strains (pvy(o), pvy(n) and pvy(c)) and several recombinant forms. pvy has a worldwide distribution, yet the mechanisms that promote and maintain its population structure and genetic diversity are still unclear. in this study, we used a pool of 77 complete pvy genomes from isolates collected worldwide. after removing the ...201222655074
phylogenetic relationships of closely related potyviruses infecting sweet potato determined by genomic characterization of sweet potato virus g and sweet potato virus 2.complete nucleotide sequences of sweet potato virus g (spvg) and sweet potato virus 2 (spv2) were determined to be 10,800 and 10,731 nucleotides, respectively, excluding the 3'-poly(a) tail. their genomic organizations are typical of potyviruses, encoding a polyprotein which is likely cleaved into 10 mature proteins by three viral proteinases. conserved motifs of orthologous proteins of viruses in the genus potyvirus are found in corresponding positions of both viruses. pairwise comparisons of i ...201222562225
pvx-potyvirus synergistic infections differentially alter microrna accumulation in nicotiana benthamiana.in comparison to single infections, co-infection of nicotiana benthamiana with potato virus x (pvx) and potato virus y (pvy) or plum pox virus (ppv), resulted in increased systemic symptoms (synergism in pathology). previous studies have shown that virus infections affected the accumulation of various micrornas (mirnas) and mirna target genes. our studies revealed that double infection by pvx and pvy or ppv that produced the most severe symptoms in n. benthamiana altered accumulation of mir156, ...201222387565
viruses of potato.potatoes are an important crop in mediterranean countries both for local consumption and for export to other countries, mainly during the winter. many mediterranean countries import certified seed potato in addition to their own seed production. the local seeds are mainly used for planting in the autumn and winter, while the imported seed are used for early and late spring plantings. potato virus y is the most important virus in mediterranean countries, present mainly in the autumn plantings. th ...201222682169
the cysteine-rich proteins of beet necrotic yellow vein virus and tobacco rattle virus contribute to efficient suppression of silencing in roots.many plant viruses encode proteins that suppress rna silencing, but little is known about the activity of silencing suppressors in roots. this study examined differences in the silencing suppression activity of different viruses in leaves and roots of nicotiana benthamiana plants. infection by tobacco mosaic virus, potato virus y and cucumber mosaic virus but not potato virus x (pvx) resulted in strong silencing suppression activity of a transgene in both leaves and roots, whereas infection by b ...201222647371
complete genome sequence of pepper yellow mosaic virus, a potyvirus, occurring in brazil.the complete genomic sequence of pepper yellow mosaic virus (pepymv), a member of the genus potyvirus, was determined. the sequence was 9745 nucleotides long, excluding the 3' poly(a) tail. the genome contained a large open reading frame encoding a polyprotein of 3085 amino acids, which contained the typically conserved motifs found in members of the genus potyvirus and an additional p3-pipo (pretty interesting potyvirus orf). in a pairwise comparison with other potyvirus sequences, the full gen ...201222527869
the recent recombinant evolution of a major crop pathogen, potato virus y.potato virus y (pvy) is a major agricultural disease that reduces crop yields worldwide. different strains of pvy are associated with differing degrees of pathogenicity, of which the most common and economically important are known to be recombinant. we need to know the evolutionary origins of pathogens to prevent further escalations of diseases, but putatively reticulate genealogies are challenging to reconstruct with standard phylogenetic approaches. currently available phylogenetic hypotheses ...201223226339
aphid feeding behavior in relation to potato virus y (pvy) acquisition.potato virus y (pvy) is transmitted by aphids in a nonpersistent manner and aphid species differ in their ability to transmit pvy. during host selection, aphids will land and probe on nonhost plant species and this behavior is an important component of the epidemiology of many aphid-transmitted viruses. in this study, we hypothesized that host selection behavior varies between aphid species and the host or nonhost status of the plant and this behavior will modulate their ability to acquire pvy. ...201223356052
rapid detection of tobacco viruses by reverse transcription loop-mediated isothermal amplification.tobacco viruses may cause a wide range of diseases that heavily reduce tobacco quality and yield worldwide. in order to detect viral diseases in tobacco fields, a one-step reverse transcription loop-mediated isothermal amplification (rt-lamp) method was established. nucleotide amplification could be observed clearly after adding sybr green i, within 60 min under isothermal conditions, at 63-65 °c with a set of primers targeting the viral coat protein (cp) genes of tobacco viruses including cucum ...201222886186
viruses of pepper crops in the mediterranean basin: a remarkable stasis.compared to other vegetable crops, the major viral constraints affecting pepper crops in the mediterranean basin have been remarkably stable for the past 20 years. among these viruses, the most prevalent ones are the seed-transmitted tobamoviruses; the aphid-transmitted potato virus y and tobacco etch virus of the genus potyvirus, and cucumber mosaic virus member of the genus cucumovirus; and thrips-transmitted tospoviruses. the last major viral emergence concerns the tospovirus tomato spotted w ...201222682167
a multiplex reverse transcription pcr assay for simultaneous detection of five tobacco viruses in tobacco plants.tobacco viruses including tobacco mosaic virus (tmv), cucumber mosaic virus (cmv), tobacco etch virus (tev), potato virus y (pvy) and tobacco vein banding mosaic virus (tvbmv) are major viruses infecting tobacco and can cause serious crop losses. a multiplex reverse transcription polymerase chain reaction assay was developed to detect simultaneously and differentiate all five viruses. the system used specific primer sets for each virus producing five distinct fragments 237, 273, 347, 456 and 547 ...201222484613
comparative analysis of rna silencing suppression activities between viral suppressors and an endogenous plant rna-dependent rna polymerase.rna silencing is an evolutionarily conserved system that functions as an antiviral mechanism in eukaryotes, including higher plants. to counteract this, several plant viruses express silencing suppressors that inhibit rna silencing in host plants. here, we show that both 2b protein from peanut stunt virus (psv) and a hairpin construct (designated hp-rdr6) that silences endogenous rna-dependent rna polymerase 6 (rdr6) strongly suppress rna silencing. the agrobacterium infiltration system was used ...201222354861
a new approach for the identification of aphid vectors (hemiptera: aphididae) of potato virus y.potato virus y (pvy) is one of the most economically important viruses affecting potato crops worldwide. pvy can be transmitted from potato to potato by several aphid species, most of which do not colonize the potato crop. new methods including preservation of viral rna on stylets of aphids collected from yellow pan trap samples, polymerase chain reaction detection of pvy from the stylets of one aphid, and aphid identification using dna barcoding were used to identify possible pvy vectors from f ...201223356053
overexpression of the wild potato eif4e-1 variant eva1 elicits potato virus y resistance in plants silenced for native eif4e-1.potato virus y (pvy) is the most important viral pathogen of cultivated potato (solanum tuberosum) from a commercial perspective, causing severe losses in both tuber quality and yield worldwide. specific accessions of wild potato species exhibit resistance against pvy but efforts to transfer the trait to cultivated material have not yielded widely adopted varieties. because amino acid substitutions at specific domains of host factor eif4e-1 often confer resistance to various crops, we sequenced ...201122146867
helper component proteinase of genus potyvirus is an interaction partner of translation initiation factors eif(iso)4e and eif4e that contains a 4e binding motif.the multifunctional helper component proteinase (hcpro) of potyviruses (genus potyvirus; potyviridae) shows self-interaction and interacts with other potyviral and host plant proteins. host proteins that are pivotal to potyvirus infection include the eukaryotic translation initiation factor eif4e and the isoform eif(iso)4e, which interact with viral genome-linked protein (vpg). here we show that hcpro of potato virus a (pva) interacts with both eif4e and eif(iso)4e, with interactions with eif(is ...201121525344
analysis of potyvirus terminal protein vpg-transgenic arabidopsis thaliana plants.virus-coded vpg protein of potato virus y (pvy) does not have homologs apart from other vpgs. since vpg is indispensable for the potyvirus life cycle, it appeared a good candidate for eliciting pathogen-derived resistance to pvy. following agroinfection used to obtain pvy vpg-transgenic arabidopsis thaliana plants, only few transgenic seeds were recovered giving rise to six transgenic plants that contained the vpg gene with the correct sequence. they generated vpg mrna, but vpg protein was not d ...201121927721
a proposal to help resolve the disagreement between naming of potato virus y strain groups defined by resistance phenotypes and those defined by sequencing.the complete coat protein (cp) nucleotide sequences of nine historical (1943-1984) potato virus y (pvy) isolates belonging to resistance strain groupings y(c), y(z) or y(o), and nine new australian isolates from potato and tomato were compared with those of 85 others. new potato isolate bl was in resistance group y(o). on phylogenetic analysis, the historical potato isolates fitted within phylogenetic groups c1 or c2 (y(c)), 'y(o)' (y(z), y(o)) or n-wi (y(z)), while the new isolates were in phyl ...201121922324
Dynamics of Responses in Compatible Potato - Potato virus Y Interaction Are Modulated by Salicylic Acid.To investigate the dynamics of the potato - Potato virus Y (PVY) compatible interaction in relation to salicylic acid - controlled pathways we performed experiments using non-transgenic potato cv. Désirée, transgenic NahG-Désirée, cv. Igor and PVY(NTN), the most aggressive strain of PVY. The importance of salicylic acid in viral multiplication and symptom development was confirmed by pronounced symptom development in NahG-Désirée, depleted in salicylic acid, and reversion of the effect after spr ...201122194976
Assessing aphids potato virus Y-transmission efficiency: A new approach.In order to develop an alternative method to optimize the relative efficiency factor (REF) assessment, the efficiency of transmission of Potato virus Y (PVY) by seven aphid species was examined. In vitro micropropagated potato plantlets were used to experiment on phenotypically and genetically homogeneous material. Species-specific acquisition access period (AAP) on a PVY-infected plantlet was assessed for each aphid species using electrical penetration graph (EPG) technique. Aphid probing behav ...201121884729
genetic diversity of potato virus y infecting tobacco crops in china.genetic variability of potato virus y (pvy) isolates infecting potato has been characterized but little is known about genetic diversity of pvy isolates infecting tobacco crops. in this study, pvy isolates were collected from major tobacco-growing areas in china and single-lesion isolates were produced by serial inoculation on chenopodium amaranticolor. most isolates (88%) caused systemic veinal necrosis symptoms in tobacco. of these, 16 isolates contained a pvy(o)-like coat protein (cp) and pvy ...201120977310
highly efficient virus resistance mediated by artificial micrornas that target the suppressor of pvx and pvy in plants.micrornas (mirnas) processed from nuclear-encoded transcripts control expression of target transcripts by directing cleavage or translational inhibition. artificial mirnas (amirnas) that exploit this endogenous gene silencing mechanism can be designed to target any gene of interest and provide a highly specific approach for effective post-transcriptional gene silencing (ptgs) in plants. here, using arabidopsis thaliana mir159a, mir167b and mir171a precursors as backbones, we designed two types o ...201121309977
p1 peptidase--a mysterious protein of family potyviridae.the potyviridae family, named after its type member, potato virus y (pvy), is the largest of the 65 plant virus groups and families currently recognized. the coding region for p1 peptidase is located at the very beginning of the viral genome of the family potyviridae. until recently p1 was thought of as serine peptidase with rna-binding activity and with possible influence in cell-to-cell viral spreading. this n-terminal protein, among all of the potyviruses, is the most divergent protein: varyi ...201121451259
within plant distribution of potato virus y in hairy nightshade (solanum sarrachoides): an inoculum source affecting pvy aphid transmission.potato virus y (pvy) is vectored by several potato-colonizing and non-colonizing aphid species in a non-persistent manner and has a wide host range. it occurs naturally in several plant families. myzus persicae and macrosiphum euphorbiae are the most efficient potato-colonizing aphid vectors of pvy. rhopalosiphum padi, a cereal aphid that migrates in large numbers through potato fields during the middle of the growing season, does not colonize potato plants but can transmit pvy. hairy nightshade ...201121601597
potato virus y mrna expression knockdown mediated by sirnas in cultured mammalian cell line.rna interference (rnai) is a powerful tool for functional gene analysis which has been successfully used to downregulate the expression levels of target genes. the goal of this research was to provide a highly robust and concise methodology for in-vitro screening of efficient sirnas from a bulk to be used as a tool to protect potato plants against pvy invasion. in our study, a 480 bp fragment of the capsid protein gene of potato virus y (cp-pvy) was used as a target to downregulate pvy mrna expr ...201121468933
characterization and functional analysis of ghrdr6, a novel rdr6 gene from cotton (gossypium hirsutum l).rna-dependent rna polymerase 6 (rdr6) is not only involved in viral resistance but also plays an important role in natural plant development. in the present study, a novel rdr gene named ghrdr6 was isolated from cotton (gossypium hirsutum l). alignment and evolutionary relationship analyses showed that ghrdr6 is more closely related to rdr6 than to other rdrs. expression analysis indicated that this single-copy gene is constitutively expressed in roots, stems and leaves. semi-quantitative rt-pcr ...201121679158
engineering broad-spectrum resistance against rna viruses in potato.rna silencing technology has become the tool of choice for inducing resistance against viruses in plants. a significant discovery of this technology is that double-stranded rna (dsrna), which is diced into small interfering rnas (sirnas), is a potent trigger for rna silencing. by exploiting this phenomenon in transgenic plants, it is possible to confer high level of virus resistance by specific targeting of cognate viral rna. in order to maximize the efficiency and versatility of the vector-base ...201121701953
an infectious full-length cdna clone of potato virus y(ntn-nw), a recently reported strain of pvy that causes potato tuber necrotic ringspot disease.a full-length infectious cdna clone of potato virus y (pvy) was constructed based on an isolate of the pvy(ntn-nw) strain, syr-ii-2-8, which is able to cause potato tuber necrotic ringspot disease (ptnrd). silent point mutations were introduced to modify sequences similar to the prokaryotic promoter elements detected at the 5' terminus of the p3 coding region of syr-ii-2-8. this, along with modification of the growing conditions of e. coli, led to the successful construction of a stable full-len ...201121761169
dn/ds-based methods detect positive selection linked to trade-offs between different fitness traits in the coat protein of potato virus y.the dn/ds ratio between nonsynonymous and synonymous substitution rates has been used extensively to identify codon positions involved in adaptive processes. however, the accuracy of this approach has been questioned and very few studies have attempted to validate experimentally its predictions. using the coat protein (cp) of potato virus y (pvy; genus potyvirus, family potyviridae) as a case study, we identified several candidate positively-selected codon positions which differed between clades ...201121498601
differential pathogenicity of two different recombinant pvyntn isolates in physalis floridana is likely determined by the coat protein gene.abstract: a previous study has identified two types of recombinant variants of potato virus y strain ntn (pvyntn) in china and sequenced the complete genome of the variant pvyntn-hn2. in this study, the complete genome of isolate pvyntn-hn1 was fully sequenced and analyzed. the most striking difference between the two variants was the location of recombinant joint three (rj3). in pvyntn-hn1, like other typical european-pvyntn isolates such as pvyntn-hun, the rj3 was located at nucleotide (nt) 91 ...201121548970
aphids preserved in propylene glycol can be used for reverse transcription-polymerase chain reaction detection of potato virus y.the effectiveness of propylene glycol on the retention of rna target of potato virus y (pvy), an aphid stylet-borne virus, in myzus persicae was investigated in comparison to ethanol and liquid nitrogen/-80°c. reverse transcription-polymerase chain reaction (rt-pcr) was used to detect the pvy targets from the propylene glycol/ethanol/liquid nitrogen preserved single aphids after a 5min acquisition period from infected potato plants. in the liquid nitrogen/-80°c and 70% ethanol treatments, 55.6% ...201121621556
genetic background matters: a plant-virus gene-for-gene interaction is strongly influenced by genetic contexts.evolutionary processes responsible for parasite adaptation to their hosts determine our capacity to manage sustainably resistant plant crops. most plant-parasite interactions studied so far correspond to gene-for-gene models in which the nature of the alleles present at a plant resistance locus and at a pathogen pathogenicity locus determine entirely the outcome of their confrontation. the interaction between the pepper pvr2 resistance locus and potato virus y (pvy) genome-linked protein vpg loc ...201121726391
[probable involvement of 3'-terminal segment of 18s rrna in translation initiation of uncapped mrnas in plants].a possibility of involvement of 3'-terminal 18s rrna segment in the cap-independent initiation of translation on plant ribosomes was studied. it was shown that 3-terminal segment (nucleotides 1777-1811) of 18s rrna including the last hairpin 45 is accessible for complementary interactions in 40s ribosomal subunits. oligonucleotides complementary to this segment of rrna when added to wheat germ cell-free protein synthesizing system were found to specifically inhibit translation of uncapped report ...201121634120
distribution of potato virus y in potato plant organs, tissues and cells.the distribution of potato virus y (pvy) in the systemically infected potato (solanum tuberosum l.) plants of the highly susceptible cultivar igor was investigated. virus presence and accumulation was analyzed in different plant organs and tissues using real-time pcr and transmission electron microscopy (tem) negative staining methods. to get a complete insight into the location of viral rna within the tissue, in situ hybridization was developed and optimised for the detection of pvy rna at the ...201121692643
a test of taxonomic and biogeographic predictivity: resistance to potato virus y in wild relatives of the cultivated potato.abstract a major justification for taxonomic research is its assumed ability to predict the presence of traits in a group for which the trait has been observed in a representative subset of the group. similarly, populations in similar environments are expected to be more alike than populations in divergent environments. consequently, it is logical to assume that taxonomic relationships and biogeographical data have the power to predict the distribution of disease resistance phenotypes among plan ...201121834726
engineering virus resistance using a modified potato gene.natural mutations in translation initiation factor eif4e confer resistance to potyviruses in many plant species. potato is a staple food crop plagued by several potyviruses, yet to date no known eif4e-mediated resistance genes have been identified. in this study, we demonstrate that transgenic expression of the pvr1(2) gene from pepper confers resistance to potato virus y (pvy) in potato. we then use this information to convert the susceptible potato ortholog of this allele into a de novo allele ...201121668622
Enhanced sensitivity to higher ozone in a pathogen-resistant tobacco cultivar.Investigations of the effects of elevated ozone (O(3)) on the virus-plant system were conducted to inform virus pathogen management strategies better. One susceptible cultivar of tobacco (Nicotiana tabacum L. cv. Yongding) and a resistant cultivar (Nicotiana tabacum L. cv. Vam) to Potato virus Y petiole necrosis strain (PVY(N)) infection were grown in open-top chambers under ambient and elevated O(3) concentrations. Above-ground biomass, foliage chlorophyll, nitrogen and total non-structural car ...201122090443
identification of the molecular make-up of the potato virus y strain pvy(z): genetic typing of pvy(z)-ntn.abstract potato virus y (pvy) strains were originally defined by interactions with different resistance genes in standard potato cultivars. five distinct strain groups are defined that cause local or systemic hypersensitive responses (hrs) in genetic background with a corresponding n gene: pvy(o), pvy(n), pvy(c), pvy(z), and pvy(e). the nucleotide sequences of multiple isolates of pvy(o) and pvy(n) differ from each other by ôëê8% along their genomes. additionally, complete genome sequences of mu ...201121834725
Status of tobacco viruses in Serbia and molecular characterization of tomato spotted wilt virus isolates. In a four-year survey to determine the presence and distribution of viruses in tobacco crops at 17 localities of the Vojvodina Province and Central Serbia, 380 samples were collected and analyzed by DAS-ELISA. Out of the seven viruses tested, tomato spotted wilt virus (TSWV), potato virus Y (PVY), tobacco mosaic virus (TMV), cucumber mosaic virus (CMV), and alfalfa mosaic virus (AMV) were detected in 37.9, 33.4, 28.7, 23.9, and 15.5% of the total tested samples, respectively. TSWV was the most ...201122149499
Genetic diversity of the ordinary strain of Potato virus Y (PVY) and origin of recombinant PVY strains.The ordinary strain of Potato virus Y (PVY), PVY(O), causes mild mosaic in tobacco and induces necrosis and severe stunting in potato cultivars carrying the Ny gene. A novel substrain of PVY(O) was recently reported, PVY(O)-O5, which is spreading in the United States and is distinguished from other PVY(O) isolates serologically (i.e., reacting to the otherwise PVY(N)-specific monoclonal antibody 1F5). To characterize this new PVY(O)-O5 subgroup and address possible reasons for its continued spre ...201121675922
Resistance to multiple viruses in transgenic tobacco expressing fused, tandem repeat, virus-derived double-stranded RNAs.Transgenic tobacco plants expressing fused, tandem, inverted-repeat, double-stranded RNAs derived either from the three viruses [potato virus Y (PVY), potato virus A (PVA), and potato leafroll virus (PLRV)] or the five viruses [PVY, PVA, PLRV as well as tobacco rattle virus (TRV), and potato mop-top virus (PMTV)] were generated in this study to examine whether resistance could be achieved against these three viruses or five viruses, respectively, in the same plant. The transgenic lines were engi ...201121853332
Potato Virus Y-Like Particles as a New Carrier for the Presentation of Foreign Protein Stretches.Virus-like particle (VLP) technology represents a promising approach for the creation of efficient vaccines and materials for use in nanotechnological applications. For construction of a new carrier for foreign protein sequences, the coat protein (CP) gene from potato virus Y (PVY) was cloned and expressed in Escherichia coli cells. The PVY CP self-assembles into PVY-like particles, as demonstrated by electron microscopy analysis of purified VLP preparations. The PVY CP with an N-terminal insert ...201122167454
development of a portable, high throughput biosensor system for rapid plant virus detection.biosensors based on living cells are characterized by high sensitivity, selectivity and rapid response times. a novel portable cell biosensor system for the detection of plant viruses, based on immobilized 'vero' cells carrying on their membrane virus specific antibodies was developed and was designated as high throughput bioelectric recognition assay (bera-htp). bera-htp was tested for the detection of purified potato virus y (pvy), cucumber mosaic virus (cmv) and tobacco rattle virus (trv) and ...201121781989
molecular characterization of two recombinant potato virus y isolates from china.isolates of potato virus y (pvy) have been divided into several strains. we determined the genomic sequences of pvy isolates aq4 and fz10 from tobacco in china. aq4 and fz10 had genome of 9700 and 9698 nucleotides, respectively. in phylogenetic analysis of complete genome sequences, aq4 was clustered with strain n-wi, and fz10 with ntn. aq4 had two recombination sites within the p1 and p3 genes, while fz10 had three within the p1, p3 and nia-pro genes. when compared to typical ntn isolates, fz10 ...201122139355
top 10 plant viruses in molecular plant pathology.many scientists, if not all, feel that their particular plant virus should appear in any list of the most important plant viruses. however, to our knowledge, no such list exists. the aim of this review was to survey all plant virologists with an association with molecular plant pathology and ask them to nominate which plant viruses they would place in a 'top 10' based on scientific/economic importance. the survey generated more than 250 votes from the international community, and allowed the gen ...201122017770
Field testing, gene flow assessment and pre-commercial studies on transgenic Solanum tuberosum spp. tuberosum (cv. Spunta) selected for PVY resistance in Argentina.Solanum tuberosum ssp. tuberosum (cv. Spunta) was transformed with a chimeric transgene containing the Potato virus Y (PVY) coat protein (CP) sequence. Screening for PVY resistance under greenhouse conditions yielded over 100 independent candidate lines. Successive field testing of selected lines allowed the identification of two genetically stable PVY-resistant lines, SY230 and SY233, which were further evaluated in field trials at different potato-producing regions in Argentina. In total, more ...201122200984
the helper component proteinase cistron of potato virus y induces hypersensitivity and resistance in potato genotypes carrying dominant resistance genes on chromosome iv.the nc(tbr) and ny(tbr) genes in solanum tuberosum determine hypersensitive reactions, characterized by necrotic reactions and restriction of the virus systemic movement, toward isolates belonging to clade c and clade o of potato virus y (pvy), respectively. we describe a new resistance from s. sparsipilum which possesses the same phenotype and specificity as nc(tbr) and is controlled by a dominant gene designated nc(spl). nc(spl) maps on potato chromosome iv close or allelic to ny(tbr). the hel ...201121405985
isolation of a novel rna-dependent rna polymerase 6 from nicotiana glutinosa, ngrdr6, and analysis of its response to biotic and abiotic stresses.rna-dependent rna polymerases (rdrs) play an important role in rna silencing, antiviral and developmental progress. here, we firstly isolated the full-length cdna, genomic dna and 5'-flanking region of rdr6 from nicotiana glutinosa (ngrdr6). sequences analysis revealed that the cdna of ngrdr6 was 3,921 bp in length, and the deduced protein consisted of 1,197 amino acids, containing all highly conserved sequence motifs that are present among all rdrs families. moreover, two introns were detected ...201120495874
molecular characterization of sunflower chlorotic mottle virus: a member of a distinct species in the genus potyvirus.the complete nucleotide (nt) and deduced amino acid (aa) sequences of the c (common) and crs (chlorotic ringspot) argentine strains of sucmov have been determined. the sucmov-c rna genome consists of 9,965 nt, whereas indels within the p1 coding region of sucmov-crs make its genomic length 15 nt shorter. nucleotide and aa sequence identities between the polyproteins of the c and crs strains of sucmov were 92.3 and 95.6%, respectively. pairwise comparisons between the polyproteins of the c and cr ...201020517623
bacterially expressed double-stranded rnas against hot-spot sequences of tobacco mosaic virus or potato virus y genome have different ability to protect tobacco from viral infection.posttranscriptional gene silencing, also known as rna interference, involves degradation of homologous mrna sequences in organisms. in plants, posttranscriptional gene silencing is part of a defense mechanism against virus infection, and double-stranded rna is the pivotal factor that induces gene silencing. in this paper, we got seven hairpin rnas (hprnas) constructs against different hot-spot sequences of tobacco mosaic virus (tmv) or potato virus y (pvy) genome. after expression in escherichia ...201020437276
complementations and exclusions between mutated versions of a potato virus y genotype during mixed infections of nicotiana hosts.understanding the processes that have led to the recent prevalence of necrotic genotypes in pvy populations is an important challenge for research programs studying this virus. non-necrotic pvy(o)-139, necrotic pvy(n)-605 and point mutated versions of pvy(n)-605 (pvy(kred), pvy(kr) and pvy(ed)), were used in mixtures to inoculate two nicotiana hosts which express (n. tabacum cv. xanthi) or not (n. clevelandii) necrosis symptoms in response to infection by pvy(n) group members. the comparison dur ...201020708049
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