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development and evaluation of a reverse transcription loop-mediated isothermal amplification assay for detection of beet necrotic yellow vein virus.sugar beet can be infected by many different viruses that can reduce yield; beet necrotic yellow vein virus (bnyvv) is one of the most economically important viruses of this crop plant. this report describes a new reverse transcription loop-mediated isothermal amplification (rt-lamp) assay for identification of bnyvv. in addition, a novel immunocapture (ic) rt-lamp assay for rapid and easy detection (without rna extraction) of bnyvv was developed here and compared with das-elisa and rt-lamp assa ...201727738843
a viral noncoding rna complements a weakened viral rna silencing suppressor and promotes efficient systemic host infection.systemic movement of beet necrotic yellow vein virus (bnyvv) in beta macrocarpa depends on viral rna3, whereas in nicotiana benthamiana this rna is dispensable. rna3 contains a coremin motif of 20 nucleotides essential for the stabilization of noncoding rna3 (ncrna3) and for long-distance movement in beta species. coremin mutants that are unable to accumulate ncrna3 also do not achieve systemic movement in beta species. a mutant virus carrying a mutation in the p14 viral suppressor of rna silenc ...201627782046
transcriptome analysis of beta macrocarpa and identification of differentially expressed transcripts in response to beet necrotic yellow vein virus infection.rhizomania is one of the most devastating diseases of sugar beet. it is caused by beet necrotic yellow vein virus (bnyvv) transmitted by the obligate root-infecting parasite polymyxa betae. beta macrocarpa, a wild beet species widely used as a systemic host in the laboratory, can be rub-inoculated with bnyvv to avoid variation associated with the presence of the vector p. betae. to better understand disease and resistance between beets and bnyvv, we characterized the transcriptome of b. macrocar ...201526196682
genetic diversity and population structure of beet necrotic yellow vein virus in china.beet necrotic yellow vein virus (bnyvv) is a serious threat to the sugar beet industry worldwide. however, little information is available regarding the genetic diversity and population structure of bnyvv in china. here, we analyzed multiple sequences from four genomic regions (cp, rna3, rna4 and rna5) of a set of chinese isolates. sequence analyses revealed that several isolates were mixed infections of variants with different genotypes and/or different p25 tetrad motifs. in total, 12 distinct ...201525997927
new bnyvv p25 variants in belgium.rhizomania is a widespread viral plant disease of major importance in sugar beet cropping and breeding. it is caused by the beet necrotic yellow vein virus (bnyvv), a benyvirus transmitted by the soil inhabiting plasmodiophorid polymyxa betae. this vector also transmits other sugar beet virus such as beet virus q (bvq) and beet soil-borne virus (bsbv). despite identification of resistance genes, bnyvv remains a major constraint because of resistance-breaking events as well as its ability to surv ...201527141738
on the interaction and localization of the beet necrotic yellow vein virus replicase.beet necrotic yellow vein virus (bnyvv) is a multipartite positive-strand rna virus. bnyvv rna-1 encodes a non-structural p237 polyprotein processed in two proteins (p150 and p66) by a cis-acting protease activity. bnyvv non-structural proteins are closely related to replication proteins of positive strand rna viruses such as hepeviruses rather to other plant virus replicases. the p237 and dsrna have been localized by tem in er structures of infected leaf cells whereas dsrna was immunolabeled in ...201525445349
infection of beet necrotic yellow vein virus with rna4-encoded p31 specifically up-regulates pathogenesis-related protein 10 in nicotiana benthamiana.beet necrotic yellow vein virus (bnyvv) is the infectious agent of sugar beet rhizomania, which consists of four or five plus-sense rnas. rna4 of bnyvv is not essential for virus propagation in nicotiana benthamiana but has a major effect on symptom expression. early reports showed that rna4-encoded p31 was associated with severe symptoms, such as curling and dwarfing, in n. benthamiana.201424961274
proteomic profiling of sugar beet (beta vulgaris) leaves during rhizomania compatible interactions.rhizomania, caused by beet necrotic yellow vein virus (bnyvv), severely impacts sugar beet (beta vulgaris) production throughout the world, and is widely prevalent in most production regions. initial efforts to characterize proteome changes focused primarily on identifying putative host factors that elicit resistant interactions with bnyvv, but as resistance breaking strains become more prevalent, effective disease control strategies will require the application of novel methods based on better ...201428250378
deep sequencing-based transcriptome profiling reveals comprehensive insights into the responses of nicotiana benthamiana to beet necrotic yellow vein virus infections containing or lacking rna4.beet necrotic yellow vein virus (bnyvv), encodes either four or five plus-sense single stranded rnas and is the causal agent of sugar beet rhizomania disease, which is widely distributed in most regions of the world. bnyvv can also infect nicotiana benthamiana systemically, and causes severe curling and stunting symptoms in the presence of rna4 or mild symptoms in the absence of rna4.201424416380
characterization of burdock mottle virus, a novel member of the genus benyvirus, and the identification of benyvirus-related sequences in the plant and insect genomes.the complete nucleotide sequence of the burdock mottle virus (bdmov) isolated from an edible burdock plant (arctium lappa) in japan has been determined. bdmov has a bipartite genome, whose organization is similar to rna1 and rna2 of benyviruses, beet necrotic yellow vein virus (bnyvv), beet soil-borne mosaic virus (bsbmv), and rice stripe necrosis virus (rsnv). bdmov rna1 (7038 nt) contains a single open reading frame (orf) encoding a 249-kda polypeptide that consists of methyl-transferase, heli ...201323911632
gene duplication is infrequent in the recent evolutionary history of rna viruses.gene duplication generates genetic novelty and redundancy and is a major mechanism of evolutionary change in bacteria and eukaryotes. to date, however, gene duplication has been reported only rarely in rna viruses. using a conservative blast approach we systematically screened for the presence of duplicated (i.e., paralogous) proteins in all rna viruses for which full genome sequences are publicly available. strikingly, we found only nine significantly supported cases of gene duplication, two of ...201323486612
effect of sugar beet genotype on the beet necrotic yellow vein virus p25 pathogenicity factor and evidence for a fitness penalty in resistance-breaking strains.beet necrotic yellow vein virus (bnyvv), vectored by polymyxa betae, causes rhizomania in sugar beet. for disease control, the cultivation of hybrids carrying rz1 resistance is crucial, but is compromised by resistance-breaking (rb) strains with specific mutations in the p25 protein at amino acids 67-70 (tetrad). to obtain evidence for p25 variability from soil-borne populations, where the virus persists for decades, populations with wild-type (wt) and rb properties were analysed by p25 deep seq ...201323282068
the benyvirus rna silencing suppressor is essential for long-distance movement, requires both zinc-finger and nols basic residues but not a nucleolar localization for its silencing-suppression activity.the rna silencing-suppression properties of beet necrotic yellow vein virus (bnyvv) and beet soil-borne mosaic virus (bsbmv) cysteine-rich p14 proteins have been investigated. suppression of rna silencing activities were made evident using viral infection of silenced nicotiana benthamiana 16c, n. benthamiana agroinfiltrated with green fluorescent protein (gfp), and gf-fg hairpin triggers supplemented with viral suppressor of rna silencing (vsr) constructs or using complementation of a silencing- ...201323013437
agroinoculation of beet necrotic yellow vein virus cdna clones results in plant systemic infection and efficient polymyxa betae transmission.agroinoculation is a quick and easy method for the infection of plants with viruses. this method involves the infiltration of tissue with a suspension of agrobacterium tumefaciens carrying binary plasmids harbouring full-length cdna copies of viral genome components. when transferred into host cells, transcription of the cdna produces rna copies of the viral genome that initiate infection. we produced full-length cdna corresponding to beet necrotic yellow vein virus (bnyvv) rnas and derived repl ...201323384276
highly specific detection of five exotic quarantine plant viruses using rt-pcr.to detect five plant viruses (beet black scorch virus, beet necrotic yellow vein virus, eggplant mottled dwarf virus, pelargonium zonate spot virus, and rice yellow mottle virus) for quarantine purposes, we designed 15 rt-pcr primer sets. primer design was based on the nucleotide sequence of the coat protein gene, which is highly conserved within species. all but one primer set successfully amplified the targets, and gradient pcrs indicated that the optimal temperature for the 14 useful primer s ...201325288934
validation of reference genes for gene expression studies in virus-infected nicotiana benthamiana using quantitative real-time pcr.nicotiana benthamiana is the most widely-used experimental host in plant virology. the recent release of the draft genome sequence for n. benthamiana consolidates its role as a model for plant-pathogen interactions. quantitative real-time pcr (qpcr) is commonly employed for quantitative gene expression analysis. for valid qpcr analysis, accurate normalisation of gene expression against an appropriate internal control is required. yet there has been little systematic investigation of reference ge ...201223029521
the p25 pathogenicity factor of beet necrotic yellow vein virus targets the sugar beet 26s proteasome involved in the induction of a hypersensitive resistance response via interaction with an f-box protein.p25, a beet necrotic yellow vein virus (bnyvv) pathogenicity factor, interacts with a sugar beet protein with high homology to arabidopsis thaliana kelch repeat containing f-box family proteins (fbk) of unknown function in yeast. fbk are members of the skp1-cullin-f-box (scf) complex that mediate protein degradation. here, we confirm this sugar beet fbk-p25 interaction in vivo and in vitro and provide evidence for in planta interaction and similar subcellular distribution in nicotiana tabacum le ...201222512382
high level resistance against rhizomania disease by simultaneously integrating two distinct defense mechanisms.with the aim of achieving durable resistance against rhizomania disease of sugar beet, the employment of different sources of resistance to beet necrotic yellow vein virus was pursued. to this purpose, nicotiana benthamiana transgenic plants that simultaneously produce dsrna originating from a conserved region of the bnyvv replicase gene and the hrpz(psph) protein in a secreted form (sp/hrpz(psph)) were produced. the integration and expression of both transgenes as well as proper production of t ...201223284692
systemic resistance induced by bacillus lipopeptides in beta vulgaris reduces infection by the rhizomania disease vector polymyxa betae.the control of rhizomania, one of the most important diseases of sugar beet caused by the beet necrotic yellow vein virus, remains limited to varietal resistance. in this study, we investigated the putative action of bacillus amylolequifaciens lipopeptides in achieving rhizomania biocontrol through the control of the virus vector polymyxa betae. some lipopeptides that are produced by bacteria, especially by plant growth-promoting rhizobacteria, have been found to induce systemic resistance in pl ...201223279057
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
beet necrotic yellow vein virus subgenomic rna3 is a cleavage product leading to stable non-coding rna required for long-distance movement.beet necrotic yellow vein virus (bnyvv) is a multipartite rna virus. bnyvv rna3 does not accumulate in non-host transgenic arabidopsis thaliana plants when expressed using a 35s promoter. however, a 3'-derivative species has been detected in transgenic plants and in transient expression assays conducted in nicotiana benthamiana and beta macrocarpa. the 3'-derivative species is similar to the previously reported subgenomic rna3 produced during virus infection. 5' race revealed that the truncated ...201222258860
isolation, cloning and large scale expression of glutathione-s-transferase (gst) protein of polymyxa betae.the plasmodiophoromycete polymyxa betae, an obligate parasite of sugar-beet roots, is a natural vector of beet necrotic yellow vein virus (bnyvv). to develop protein based diagnosis for any pathogenic agents including p. betae, a specific immunogenic protein has to be prepared. the glutathione-s-transferase (gst) is expressed in all the morphologically different stages of the pathogen's life cycle, and then it is a good candidate as an immunogenic agent for developing of specific antibodies and ...201223878968
development of high-throughput quantum dot biosensor against polymyxa species.the plasmodiophoromycete polymyxa betae and p. graminis are eukaryotic biotrophic parasites residing in the roots of chenopodiacae and gramineae plants. they are natural transmitting agents of several important plant viruses such as are beet necrotic yellow vein virus (bnyw), beet soil borne mosaic virus (bsbmv), wheat soil-borne mosaic virus (wsbmv). developing advanced high-throughput diagnostic methods capable of accurate detection of these pathogens could assist with the screening programs a ...201223878956
expression of the beet necrotic yellow vein virus p25 protein induces hormonal changes and a root branching phenotype in arabidopsis thaliana.the rna-3-encoded p25 protein was previously characterized as one of the major symptom determinants of the beet necrotic yellow vein virus. previous analyses reported the influence of the p25 protein in root proliferation phenotype observed in rhizomania disease on infected sugar beets (beta vulgaris). a transgenic approach was developed, in which the p25 protein was constitutively expressed in arabidopsis thaliana columbia (col-0) ecotype in order to provide new clues as to how the p25 protein ...201120602166
the evolutionary history of beet necrotic yellow vein virus deduced from genetic variation, geographical origin and spread, and the breaking of host resistance.beet necrotic yellow vein virus (bnyvv) is an economically important pathogen of sugar beet and has been found worldwide, probably as the result of recent worldwide spread. the bnyvv genome consists of four or five rna components. here, we report analysis of sequence variation in the rna3-p25, rna4-p31, rna2-cp, and rna5-p26 genes of 73 worldwide isolates. the rna3-p25 gene encodes virulence and avirulence factors. these four sets of gene sequences each fell into two to four groups, of which the ...201120977309
analysis of the resistance-breaking ability of different beet necrotic yellow vein virus isolates loaded into a single polymyxa betae population in soil.the genome of most beet necrotic yellow vein virus (bnyvv) isolates is comprised of four rnas. the ability of certain isolates to overcome rz1-mediated resistance in sugar beet grown in the united states and europe is associated with point mutations in the pathogenicity factor p25. when the virus is inoculated mechanically into sugar beet roots at high density, the ability depends on an alanine to valine substitution at p25 position 67. increased aggressiveness is shown by bnyvv p type isolates, ...201121303211
the hrpz gene of pseudomonas syringae pv. phaseolicola enhances resistance to rhizomania disease in transgenic nicotiana benthamiana and sugar beet.to explore possible sources of transgenic resistance to the rhizomania-causing beet necrotic yellow vein virus (bnyvv), nicotiana benthamiana plants were constructed to express the harpin of pseudomonas syringae pv. phaseolicola (hrpz(psph)). the hrpz protein was expressed as an n-terminal fusion to the pr1 signal peptide (sp/hrpz) to direct harpin accumulation to the plant apoplast. transgene integration was verified by mpcr in all primary transformants (t0), while immunoblot analysis confirmed ...201121394206
detection and characterization of spontaneous internal deletion mutants of beet necrotic yellow vein virus rna3 from systemic host nicotiana benthamiana.beet necrotic yellow vein virus (bnyvv) is a member of the genus benyvirus causing a worldwide sugar beet disease rhizomania. bnyvv contains four or five plus-sense single stranded rnas. in altered selective conditions, multipartite rna viruses of plant are prone to undergoing internal deletions, thus turning into defective rnas (d rnas). although several d rnas have been reported in bnyvv infection, the spontaneous internal deletion mutants responsible for severe symptom in systemic host nicoti ...201121718549
in vitro dual culture of polymyxa betae in agrobacterium rhizogenes transformed sugar beet hairy roots in liquid media.abstract. polymyxa betae is a soil-borne protist and an obligate parasite of sugar beet that transmits the beet necrotic yellow vein virus. sugar beet hairy roots, transformed by agrobacterium rhizogenes, were inoculated with surface-sterilized root fragments infected by p. betae. after 10ôçâwk in a liquid medium, typical structures of p. betae were observed in this in vitro system. this first in vitro culture of p. betae in liquid medium will contribute to a better understanding of this protist ...201121699623
beet soil-borne mosaic virus rna-4 encodes a 32kda protein involved in symptom expression and in virus transmission through polymyxa betae.beet soil-borne mosaic virus (bsbmv), like beet necrotic yellow vein virus (bnyvv), is a member of the benyvirus genus and both are transmitted by polymyxa betae. both viruses possess a similar genomic organization: rna-1 and -2 are essential for infection and replication while rna-3 and -4 play important roles in disease development and vector-mediated infection in sugar beet roots. we characterized a new species of bsbmv rna-4 that encodes a 32kda protein and a chimeric form of bsbmv rna-3 and ...201122209119
testing the 3'-untranslated rna regions of beet necrotic yellow vein virus and beet yellows virus as inducers of posttranscriptional gene silencing. 201121928144
identification of beet necrotic yellow vein virus in lakes district: a major beet growing area in turkey.this study was conducted to determine the prevalence of beet necrotic yellow vein virus (bnyvv) causal agent of rhizomania, in sugar beet cultivation areas in the lakes district of turkey, in 2006-2007. during surveys bnyvv suspected leaf, root, and soil samples were collected. total of 203 soil samples were collected from different locations in the region. sugar beet cultivar kasandra plants were grown in these soil samples using bait plant techniques. in order to detect the structures of the v ...201123637514
host effect on the genetic diversification of beet necrotic yellow vein virus single-plant populations.theoretical models predict that, under restrictive host conditions, virus populations will exhibit greater genetic variability. this virus response has been experimentally demonstrated in a few cases but its relation with a virus's capability to overcome plant resistance is unknown. to explore the genetic host effects on beet necrotic yellow vein virus (bnyvv) populations that might be related to resistance durability, a wild-type virus isolate was vector inoculated into partially resistant rz1, ...201020649415
p0 proteins of european beet-infecting poleroviruses display variable rna silencing suppression activity.post-transcriptional gene silencing (ptgs), or rna silencing, is one of the key mechanisms of antiviral defence used by plants. to counter this defence response, viruses produce suppressor proteins that are able to inhibit the ptgs pathway or to interfere with some of its function. the aim of this study was to evaluate the rna silencing suppressor (rss) activity of p0 proteins from selected european isolates of the beet-infecting poleroviruses beet chlorosis virus (bchv) and beet mild yellowing ...201019955562
breakdown of host resistance by independent evolutionary lineages of beet necrotic yellow vein virus involves a parallel c/u mutation in its p25 gene.abstract breakdown of sugar beet rz1-mediated resistance against beet necrotic yellow vein virus (bnyvv) infection was previously found, by reverse genetics, to be caused by a single mutation in its p25 gene. the possibility of alternative breaking mutations, however, has not been discarded. to explore the natural diversity of bnyvv in the field and its effects on overcoming rz1, wild-type (wt) and resistance-breaking (rb) p25 genes from diverse production regions of north america were character ...201020055646
characterization and diagnostic potential of foreign epitope-presenting ty1 virus-like particles expressed in escherichia coli and pichia pastoris.we expressed a truncated p1 protein (p1-379) from the saccharomyces cerevisiae retrotransposon ty1 in the cytosol of escherichia coli and pichia pastoris, achieving maximum expression levels of 20 and 65 mg/l, respectively. two well-characterized epitopes from beet necrotic yellow vein virus (bnyvv) were used to evaluate the virus-like particles (vlps) as a presentation system for synthetic antigens. the epitopes were placed near the externally located n-terminus and at the internally located c- ...201020068357
bnyvv-derived dsrna confers resistance to rhizomania disease of sugar beet as evidenced by a novel transgenic hairy root approach.agrobacterium rhizogenes-transformed sugar beet hairy roots, expressing dsrna from the beet necrotic yellow vein virus replicase gene, were used as a novel approach to assess the efficacy of three intron-hairpin constructs at conferring resistance to rhizomania disease. genetically engineered roots were similar in morphology to wild type roots but were characterized by a profound abundancy, rapid growth rate and, in some cases, plagiotropic development. upon challenge inoculation, seedlings show ...201020127510
the first 17 amino acids of the beet necrotic yellow vein virus rna-5-encoded p26 protein are sufficient to activate transcription in a yeast one-hybrid system.the beet necrotic yellow vein virus (bnyvv) rna-5-encoded p26 protein is involved in the accentuation of symptoms expression of infected chenopodium quinoa plants and is capable of transcription activation (ta) in yeast. ta was previously localized within the first 55 residues of the p26 protein. interestingly, ta did not occur when c-terminally deleted forms of p26 were used. we used a genetic screen in the yeast one-hybrid system to select restored ta from randomly generated mutants. the ta do ...200919137435
beet soil-borne mosaic virus rna-3 is replicated and encapsidated in the presence of bnyvv rna-1 and -2 and allows long distance movement in beta macrocarpa.beet soil-borne mosaic virus (bsbmv) and beet necrotic yellow vein virus (bnyvv) belong to the benyvirus genus. bsbmv has been reported only in the united states, while bnyvv has a worldwide distribution. both viruses are vectored by polymyxa betae and possess similar host ranges, particle number and morphology. bnyvv and bsbmv are not serologically related but they have similar genomic organizations. field isolates usually consist of four rna species but some bnyvv isolates contain a fifth rna. ...200919141358
progress towards the understanding and control of sugar beet rhizomania disease.rhizomania is a soil-borne disease that occurs throughout the major sugar beet growing regions of the world, causing severe yield losses in the absence of effective control measures. it is caused by beet necrotic yellow vein virus (bnyvv), which is transmitted by the obligate root-infecting parasite polymyxa betae. bnyvv has a multipartite rna genome with all natural isolates containing four rna species, although some isolates have a fifth rna. the larger rna1 and rna2 contain the housekeeping g ...200919161359
a single u/c nucleotide substitution changing alanine to valine in the beet necrotic yellow vein virus p25 protein promotes increased virus accumulation in roots of mechanically inoculated, partially resistant sugar beet seedlings.beet necrotic yellow vein virus (bnyvv) a type isolates e12 and s8, originating from areas where resistance-breaking had or had not been observed, respectively, served as starting material for studying the influence of sequence variations in bnyvv rna 3 on virus accumulation in partially resistant sugar beet varieties. sub-isolates containing only rnas 1 and 2 were obtained by serial local lesion passages; biologically active cdna clones were prepared for rnas 3 which differed in their coding se ...200919218223
iranian beet necrotic yellow vein virus (bnyvv): pronounced diversity of the p25 coding region in a-type bnyvv and identification of p-type bnyvv lacking a fifth rna species.beet necrotic yellow vein virus (bnyvv) was detected in 288 of the 392 samples collected in iran. a-type bnyvv was detected most frequently. the p25 coding region on bnyvv rna-3 was amplified by rt-pcr and sequenced. nine different variants of the highly variable amino acid tetrad at positions 67-70 of p25 were identified, i.e. achg, ahhg, ayhg, alhg, afhr, afhg, ahyg, vlhg and vhhg. these are more different tetrad variants than have been reported from any other country. the first three variants ...200919219576
rapid screening of rna silencing suppressors by using a recombinant virus derived from beet necrotic yellow vein virus.to counteract plant defence mechanisms, plant viruses have evolved to encode rna silencing suppressor (rss) proteins. these proteins can be identified by a range of silencing suppressor assays. here, we describe a simple method using beet necrotic yellow vein virus (bnyvv) that allows a rapid screening of rss activity. the viral inoculum consisted of bnyvv rna1, which encodes proteins involved in viral replication, and two bnyvv-derived replicons: rep3-p30, which expresses the movement protein p ...200919570958
identification of beet necrotic yellow vein virus p25 pathogenicity factor-interacting sugar beet proteins that represent putative virus targets or components of plant resistance.beet necrotic yellow vein virus (bnyvv) induces the most important disease threatening sugar beet. the growth of partially resistant hybrids carrying monogenic dominant resistance genes stabilize yield but are unable to entirely prevent virus infection and replication. p25 is responsible for symptom development and previous studies have shown that recently occurring resistance-breaking isolates possess increased p25 variability. to better understand the viral pathogenicity factor's interplay wit ...200919589075
isolation of bnyvv coat protein-specific single chain fv from a mouse phage library antibody.beet necrotic yellow vein virus (bnyvv) infects sugar beet plants worldwide and is responsible for the rhizomania disease and severe economic losses. disease severity and lack of naturally occurring resistant plants make it very difficult to control the virus, both from epidemiological and economic standpoints. therefore, early detection is vital to impose hygiene restrictions and prevent further spread of the virus in the field. immunoassays are one of the most popular methodologies for the pri ...200919857111
efficient dsrna-mediated transgenic resistance to beet necrotic yellow vein virus in sugar beets is not affected by other soilborne and aphid-transmitted viruses.rhizomania caused by beet necrotic yellow vein virus (bnyvv) is one of the most devastating sugar beet diseases. sugar beet plants engineered to express a 0.4 kb inverted repeat construct based on the bnyvv replicase gene accumulated the transgene mrna to similar levels in leaves and roots, whereas accumulation of the transgene-homologous sirna was more pronounced in roots. the roots expressed high levels of resistance to bnyvv transmitted by the vector, polymyxa betae. resistance to bnyvv was n ...200817431806
phylogenetic analysis of beet necrotic yellow vein virus isolates from china.a survey detected beet necrotic yellow vein virus (bnyvv) infection in six chinese sugar-beet-growing regions. to study the diversity of virus isolates among the regions, nucleotide sequences of four proteins, namely cp, p25, p31, and p26, were determined and the amino acid sequences thus deduced were analyzed using sequence alignments and the phylogenetic method, respectively. amino acid sequence analysis of cp revealed a-type isolates in harbin, hohhot, baotou, wuwei, and jiuquan and b-type is ...200818224433
identification of amino acids of the beet necrotic yellow vein virus p25 protein required for induction of the resistance response in leaves of beta vulgaris plants.the rna3-encoded p25 protein of beet necrotic yellow vein virus (bnyvv) is responsible for the production of rhizomania symptoms of sugar beet roots (beta vulgaris subsp. vulgaris). here, it was found that the presence of the p25 protein is also associated with the resistance response in rub-inoculated leaves of sugar beet and wild beet (beta vulgaris subsp. maritima) plants. the resistance phenotype displayed a range of symptoms from no visible lesions to necrotic or greyish lesions at the inoc ...200818420811
changes in the intraisolate genetic structure of beet necrotic yellow vein virus populations associated with plant resistance breakdown.the causal agent of rhizomania disease, beet necrotic yellow vein virus (bnyvv), typically produces asymptomatic root-limited infections in sugar beets (beta vulgaris) carrying the rz1-allele. unfortunately, this dominant resistance has been recently overcome. multiple cdna clones of the viral pathogenic determinant p25, derived from populations infecting susceptible or resistant plants, were sequenced to identify host effects on the viral population structure. populations isolated from compatib ...200818423510
molecular and serological characterization of an iranian isolate of beet black scorch virus.an isolate of beet black scorch virus (bbsv) was obtained from iranian sugar beet roots. its genome organization closely resembles that of the previously described chinese and north american isolates, but the nucleotide sequences of the three isolates differ considerably. most of the nucleotide exchanges, however, are silent, and the iranian and the chinese isolates were serologically indistinguishable. beets infected by the iranian bbsv did not show black scorch symptoms, but severe root bearde ...200818548319
distribution of various types and p25 subtypes of beet necrotic yellow vein virus in germany and other european countries.the distribution of various beet necrotic yellow vein virus (bnyvv) genotypes was studied using beet samples received from germany and neighbouring countries. almost exclusively b type bnyvv was detected in germany, whereas in neighbouring countries bnyvv a types with different compositions of the amino acid tetrad in positions 67-70 of the rna-3-encoded p25 are widely distributed. neither a types nor the p type have been able to become established in germany in the past decades, although there ...200818974924
identification of differentially expressed root genes upon rhizomania disease.rhizomania is one of the most devastating sugar beet diseases. it is caused by beet necrotic yellow vein virus (bnyvv), which induces abnormal rootlet proliferation. to understand better the physiological and molecular basis of the disorder, transcriptome analysis was performed by restriction fragment differential display polymerase chain reaction (rfdd-pcr), which provided differential gene expression profiles between non-infected and infected sugar beet roots. two distinct viral isolates were ...200819019003
mutations associated with resistance-breaking isolates of beet necrotic yellow vein virus and their allelic discrimination using taqman technology.abstract genetic resistance in sugar beet (beta vulgaris) to beet necrotic yellow vein virus (bnyvv), which causes the disease rhizomania, is conferred by the single dominant gene rz1. however, since 2002, rz1 cultivars grown in the imperial valley of california have been increasingly damaged by a new strain of bnyvv. viral rna 3 was extracted from asymptomatic and symptomatic sugar beets and, after amplification and sequencing of a region including the p25 cistron, two polymorphic sites, a67v a ...200718943652
occurrence of two different types of rna-5-containing beet necrotic yellow vein virus in the uk.two types of rna-5-containing beet necrotic yellow vein virus (bnyvv) have been detected in the uk at different sites in norfolk. on the basis of nucleotide (nt) sequence comparisons, one virus source (uk-mh) was clearly identified as p type bnyvv, a virus type that had previously only been detected in two widely separated parts of the world, france and kazakhstan. the other virus source (uk-ff) has a complex genome composition. the analysed portions of its rnas 2 and 4 are closely related to th ...200716941060
genetic stability of recombinant potato virus x virus vectors presenting foreign epitopes.we investigated the genetic stability of recombinant potato virus x vectors presenting beet necrotic yellow vein virus (bnyvv) epitopes. following n-terminal pvx coat protein (cp) fusion of the bnyvv epitopes, we inoculated nicotiana benthamiana plants with recombinant (r)pvx and carried out five serial passages through systemically-infected plants. rt-pcr investigation of the bnyvv epitope sequences revealed the accumulation of several point mutations and deletions, predominantly affecting posi ...200717216135
an anchored linkage map for sugar beet based on aflp, snp and rapd markers and qtl mapping of a new source of resistance to beet necrotic yellow vein virus.rhizomania, caused by beet necrotic yellow vein virus (bnyvv), is an important sugar-beet disease worldwide and can result in severe losses of root yield and sugar content. we have identified a major qtl for bnyvv resistance from a new source in a segregating population of 158 individuals. the qtl explained an estimated 78% of the observed phenotypic variation and the gene conferring the partial resistance is referred to as rz4. aflp was used in combination with bulked segregant analysis (bsa) t ...200717333102
sequence variation within beet necrotic yellow vein virus p25 protein influences its oligomerization and isolate pathogenicity on tetragonia expansa.the p25 protein encoded by beet necrotic yellow vein virus (bnyvv) rna-3 is a pathogenicity determinant that has been implicated in symptom exacerbation on chenopodiaceae hosts. several p25 variants exist within natural isolates and p25 sequence variation may influence the degree of pathogenicity of such bnyvv isolates. expression of p25 from natural a- and p-type isolates in the background of b-type bnyvv cdna clones gave symptom discrepancies when compared to b-type p25 expression. such pathog ...200717350709
beet necrotic yellow vein virus accumulates inside resting spores and zoosporangia of its vector polymyxa betae bnyvv infects p. betae.plasmodiophorids and chytrids are zoosporic parasites of algae and land plant and are distributed worldwide. there are 35 species belonging to the order plasmodiophorales and three species, polymyxa betae, p. graminis, and spongospora subterranea, are plant viral vectors. plasmodiophorid transmitted viruses are positive strand rna viruses belonging to five genera. beet necrotic yellow vein virus (bnyvv) and its vector, p. betae, are the causal agents for rhizomania.200717411435
rna4-encoded p31 of beet necrotic yellow vein virus is involved in efficient vector transmission, symptom severity and silencing suppression in roots.rna3 and rna4 of beet necrotic yellow vein virus (bnyvv) are not essential for virus multiplication, but are associated with vector-mediated infection and disease development in sugar beet roots. here, a unique role for rna4 in virus transmission, virulence and rna silencing suppression was demonstrated. mutagenic analysis revealed that the rna4-encoded p31 open reading frame (orf) was involved in efficient vector transmission and slight enhancement of symptom expression in some beta species. no ...200717412994
zygocactus virus x-based expression vectors and formation of rod-shaped virus-like particles in plants by the expressed coat proteins of beet necrotic yellow vein virus and soil-borne cereal mosaic virus.expression vectors were constructed from 35s promoter-containing full-length cdna clones of zygocactus virus x (zvx). the expression of foreign genes was driven by the zvx coat protein (cp) subgenomic promoter. it was successful only when the variable region downstream of the conserved putative promoter region gsttaagtt(x(12-13))gaa was retained. most of the zvx cp gene, except for a short 3' part, was replaced by the corresponding sequence of the related schlumbergera virus x (svx) and its cp s ...200616432032
the use of real-time rt-pcr (taqman) and post-elisa virus release for the detection of beet necrotic yellow vein virus types containing rna 5 and its comparison with conventional rt-pcr.real-time rt-pcr (taqman) assays were developed for the specific detection of beet necrotic yellow vein virus (bnyvv). the two assays designed were a broad-spectrum one that detected rna 2 from all types and a second designed to detect types containing rna 5. the assays were validated against a range of different isolates from europe and the far east. these real-time assays were compared to a conventional rt-pcr assay for the detection of rna 5. sensitivity comparisons showed that for the detect ...200515582701
use of a beet necrotic yellow vein virus rna-5-derived replicon as a new tool for gene expression.a new gene-expression system based on rna-5 of beet necrotic yellow vein virus (bnyvv) was constructed to allow the expression of recombinant proteins in virally infected cells. replication and expression levels of the rna-5-based replicon containing the green fluorescence protein (gfp) gene were compared with those obtained with the well-characterized rna-3-derived replicon (rep-3). when rna-3 and/or rna-4 bnyvv rnas were added to the inoculum, the expression levels of rna-5-encoded gfp were co ...200515659766
comparison of the beet necrotic yellow vein virus p75 nucleotide sequences of belgian type a and type b sources.rna-2 p75 open reading frame sequencing was conducted on bnyvv-infected sugar beet plants originating from 10 belgian sources and was compared with sequences originating from france, kazakhstan, japan and china. this allowed the characterization of types a and b in belgium. sequence analysis confirmed that type a is intermediate between types p and b. the analysis of nucleotide sequences of the capsid protein epitopes and of different motifs involved in the transmission of the virus to the plant ...200515681050
nonregulated expression of tgbp3 of hordei-like viruses but not of potex-like viruses inhibits beet necrotic yellow vein virus cell-to-cell movement.plant viruses containing a triple gene block (tgb) movement protein gene cassette fall into two classes. we have shown previously that the third tgb protein (tgbp3) of beet necrotic yellow vein virus (bnyvv; class 1) and peanut clump virus (class 1) inhibit bnyvv intercellular movement when expressed from a co-inoculated bnyvv rna 3-based replicon. here we show that autonomous expression of tgbp3's of four other class 1 viruses of various genera also inhibits bnyvv movement. no such effect was o ...200515770352
evidence that rna silencing-mediated resistance to beet necrotic yellow vein virus is less effective in roots than in leaves.in plants, rna silencing is part of a defense mechanism against virus infection but there is little information as to whether rna silencing-mediated resistance functions similarly in roots and leaves. we have obtained transgenic nicotiana benthamiana plants encoding the coat protein readthrough domain open reading frame (54 kda) of beet necrotic yellow vein virus (bnyvv), which either showed a highly resistant or a recovery phenotype following foliar rub-inoculation with bnyvv. these phenotypes ...200515782633
functional characterization of the beet necrotic yellow vein virus rna-5-encoded p26 protein: evidence for structural pathogenicity determinants.a beet necrotic yellow vein virus isolate containing a fifth rna is present in the pithiviers area of france. a full-length cdna clone of rna-5 was obtained and placed under the control of a t(7)-rna-pol promoter that allowed the production of infectious transcripts. "pithiviers" isolate-specific necrotic symptoms were obtained on chenopodium quinoa when rna-5-encoded p26 was expressed either from rna-5 or from an rna-3-derived replicon. by using haemagglutinin- and green fluorescent protein-tag ...200515958690
sequence divergence of four soilborne sugarbeet-infecting viruses.soilborne viruses are among the most harmful pathogens of sugarbeet (beta vulgaris l.ssp. vulgaris) but most of them lack information on genetic variability due to paucity of sequence data. only one isolate of beet soil borne virus (bsbv; genus pomovirus), beet virus q (bvq; genus pomovirus) and beet soil borne mosaic virus (bsbmv; genus benyvirus) has been characterised for the coat protein (cp) gene. in this study, the cp gene sequences of three isolates each of bsbv and beet necrotic yellow v ...200515965609
molecular basis for mitochondrial localization of viral particles during beet necrotic yellow vein virus infection.during infection, beet necrotic yellow vein virus (bnyvv) particles localize transiently to the cytosolic surfaces of mitochondria. to understand the molecular basis and significance of this localization, we analyzed the targeting and membrane insertion properties of the viral proteins. orf1 of bnyvv rna-2 encodes the 21-kda major coat protein, while orf2 codes for a 75-kda minor coat protein (p75) by readthrough of the orf1 stop codon. bioinformatic analysis highlighted a putative mitochondrial ...200516014959
subcellular localization of the triple gene block movement proteins of beet necrotic yellow vein virus by electron microscopy.the triple gene block proteins tgbp1, tgbp2, and tgbp3 of beet necrotic yellow vein virus (bnyvv) are required for efficient cell-to-cell spread of the infection. the tgb proteins can drive cell-to-cell movement of bnyvv in trans when expressed from a co-inoculated bnyvv rna 3-based 'replicon'. tgbp2 and tgbp3 expressed from the replicon were nonfunctional in this assay if they were fused to the green fluorescent protein (gfp), but addition of a hemagglutinin (ha) tag to their c-termini did not ...200516023167
phylogenetic analysis of isolates of beet necrotic yellow vein virus collected worldwide.a study of molecular diversity was carried out on 136 sugar beets infected with beet necrotic yellow vein virus (bnyvv, benyvirus) collected worldwide. the nucleotide sequences of the rna-2-encoded cp, rna-3-encoded p25 and rna-5-encoded p26 proteins were analysed. the resulting phylogenetic trees allowed bnyvv to be classified into groups that show correlations between the virus clusters and geographic origins. the selective constraints on these three sequences were measured by estimating the r ...200516186246
expression of multiple foreign epitopes presented as synthetic antigens on the surface of potato virus x particles.we describe the construction of recombinant potato virus x (pvx) vectors expressing two different epitopes, ep4 and ep6, from beet necrotic yellow vein virus (bnyvv). the seven-amino-acid epitopes were expressed as n-terminal coat protein fusions and were displayed on the surface of pvx particles. particle assembly into full virions was successful even though no wild type coat protein subunits were present, and the epitopes could be detected in crude extracts and purified virus preparations with ...200515503224
evidence for presence of types a and b of beet necrotic yellow vein virus (bnyvv) in iran.rhizomania a viral disease, caused by beet necrotic yellow vein benyvirus (bnyvv), is now widely spread, throughout the sugar beet growing areas of iran. genomes of bnyvv are composed of five rna molecules with specific functions. in this study sequence analyses were conducted on the major coat protein gene (cp21), and parts of rna3 and rna4 of an iranian strain of bnyvv from the fars province. sequence alignments of iran fars cp21 with other isolates showed closed similarities at nucleotide and ...200415550776
strategies for the detection of potential beet necrotic yellow vein virus genome recombinations which might arise as a result of growing a type coat protein gene-expressing sugarbeets in soil containing b type virus.we have searched for beet necrotic yellow vein virus (bnyvv) populations with a recombined genome which could possibly arise when transgenic sugarbeets expressing the coat protein gene of a type bnyvv are grown in soil containing polymyxa betae carrying b type bnyvv, in soil samples from previous field release experiments and in a greenhouse model experiment. in order to accelerate the potential evolution of virus populations with recombined genomes in the model experiment, eight successive crop ...200415070072
nucleo-cytoplasmic shuttling of the beet necrotic yellow vein virus rna-3-encoded p25 protein.the protein p25 encoded by beet necrotic yellow vein virus (bnyvv) rna-3 is involved in symptom expression of infected plants. confocal microscopy analysis of wild-type and mutated p25 fused to gfp and transiently expressed in by-2 tobacco suspension cells identified a nuclear localization signal (nls) in the n-terminal part of the protein. functionality of the nls was confirmed by pull-down assays using rice and pepper importin-alpha. furthermore, it was demonstrated that p25 contains a nuclear ...200415269388
a multiplex rt-pcr assay capable of distinguishing beet necrotic yellow vein virus types a and b.a multiplex reverse-transcription polymerase chain assay (mrt-pcr) was developed, based on primers designed to distinguish the a and b types of beet necrotic yellow vein virus (bnyvv). rna was extracted from 72 bnyvv isolates from asia, europe and north america, and the type of each isolate determined using an established detection method based on single strand conformation polymorphisms (sscps). an area of the 'triple gene block' region on rna 2 was amplified and sequenced from 16 isolates of t ...200415664049
multiplex reverse transcription-pcr for simultaneous detection of beet necrotic yellow vein virus, beet soilborne virus, and beet virus q and their vector polymyxa betae keskin on sugar beet.three soilborne viruses transmitted by polymyxa betae keskin in sugar beet have been described: beet necrotic yellow vein virus (bnyvv), the agent of rhizomania, beet soilborne virus (bsbv), and beet virus q (bvq). a multiplex reverse transcription-pcr technique was developed to simultaneously detect bnyvv, bsbv, and bvq, together with their vector, p. betae. the detection threshold of the test was up to 128 times greater than that of an enzyme-linked immunosorbent assay. systematic association ...200312676720
ecology and epidemiology of benyviruses and plasmodiophorid vectors.beet necrotic yellow vein virus (bnyvv) and beet soilborne mosaic virus (bsbmv) are members of the genus benyvirus, and burdock mottle virus (bdmv) is a tentative member. bnyvv and bsbmv are vectored by the plasmodiophorid polymyxa betae, which has a worldwide distribution. polymyxa betae is morphologically indistinguishable from p. graminis, but recent molecular studies support separation of the two species. the geographic distribution of bnyvv is also worldwide, but bsbmv has been identified o ...200314527334
remote detection of rhizomania in sugar beets.abstract as a prelude to remote sensing of rhizomania, hyper-spectral leaf reflectance and multi-spectral canopy reflectance were used to study the physiological differences between healthy sugar beets and beets infested with beet necrotic yellow vein virus. this study was conducted over time in the presence of declining nitrogen levels. total leaf nitrogen was significantly lower in symptomatic beets than in healthy beets. chlorophyll and carotenoid levels were reduced in symptomatic beets. veg ...200318943059
effect of subsoiling on the yield of sugar beet under conditions of rhizomania infection.the rhizomania is known in hungary since 1982. the causal agent, beet necrotic yellow vein benyvirus (bnyvv) is transmitted by a soil-borne fungus polymyxa betae keskin. a field experiment was done under rhizomania infested and non-infested conditions to compare the yield parameters of five tolerant and four sensitive sugar beet hybrids. tolerant varieties produced higher root yield under rhizomania infected conditions. the root yields of the sensitive varieties were similar to the tolerant ones ...200212701439
development of a highly sensitive nested rt-pcr method for beet necrotic yellow vein virus detection.a diagnostic test incorporating reverse-transcription polymerase chain reaction (rt-pcr) and nested polymerase chain reaction (npcr) was developed for the detection of beet necrotic yellow vein virus (bnyvv). the rt-pcr used the primers designed by (henry et al., j. virol. methods 54 (1995)15) but refinements were made to the protocol including simplification of the extraction method, the use of standard reagents and adoption of a one-step procedure. none of these changes impaired sensitivity or ...200111377723
beet necrotic yellow vein virus particles localize to mitochondria during infection.fluorescent beet necrotic yellow vein virus (bnyvv) particles were produced by replacing part of the readthrough domain of the minor coat protein p75 with the green fluorescent protein (gfp). the recombinant virus was functional in plants and p75-gfp was incorporated at one end of the rod-shaped virions. laser scanning confocal microscopy and transmission electron microscopy showed that virus-like particles, almost certainly authentic bnyvv virions, localized to the cytoplasmic surface of mitoch ...200111485394
plant virus transmission by plasmodiophorid fungi is associated with distinctive transmembrane regions of virus-encoded proteins.computer analysis of published sequence data has consistently identified two complementary transmembrane domains in the coat protein readthrough domains of benyviruses, furoviruses and pomoviruses and in the p2 proteins of bymoviruses. these viruses differ in genome organisation but are all transmitted by plasmodiophorid fungi. the second domain is absent or disrupted in naturally-occurring deletion mutants that cannot be fungally-transmitted. in a non-transmissible substitution mutant of beet n ...200111504421
rapid screening for dominant negative mutations in the beet necrotic yellow vein virus triple gene block proteins p13 and p15 using a viral replicon.point mutations were introduced into the genes encoding the triple gene bock movement proteins p13 and p15 of beet necrotic yellow vein virus (bnyvv). mutations which disabled viral cell-to-cell movement in chenopodium quinoa were then tested for their ability to act as dominant negative inhibiters of movement of wild-type bnyvv when expressed from a co-inoculated bnyvv rna 3-based replicon. for p13, three types of mutation inhibited the movement function: non-synomynous mutations in the n- and ...200111592709
complete nucleotide sequence and genome organization of beet soilborne mosaic virus, a proposed member of the genus benyvirus.the complete nucleotide sequences of rnas 1 to 4 of beet soilborne mosaic virus (bsbmv) were determined. the genomic organization of bsbmv is identical to beet necrotic yellow vein virus (bnyvv), the type species of the genus benyvirus. bsbmv rna1 encodes a single large open reading frame (orf) with similar replicase-associated motifs identified for bnyvv. bsbmv rna2 has six potential orfs with an organization resembling bnyvv rna2. rna3 and rna4 resemble the analogous bnyvv rnas, which encode p ...200111811691
monitoring gene flow from transgenic sugar beet using cytoplasmic male-sterile bait plants.one of the most discussed environmental effects associated with the use of transgenic plants is the flow of genes to plants in the environment. the flow of genes may occur through pollen since it is the reproductive system that is designed for gene movement. pollen-mediated gene escape is hard to control in mating plants. pollen from a wind pollinator can move over distances of more than 1000 m. to investigate the efficiency of transgenic pollen movement under realistic environmental conditions, ...200011123616
a century of plant virus management in the salinas valley of california, 'east of eden'.the mild climate of the salinas valley, ca lends itself well to a diverse agricultural industry. however, the diversity of weeds, crops and insect and fungal vectors also provide favorable conditions for plant virus disease development. this paper considers the incidence and management of several plant viruses that have caused serious epidemics and been significant in the agricultural development of the salinas valley during the 20th century. beet curly top virus (bctv) almost destroyed the newl ...200011137170
[expression of single-chain fv antibody for anti-beet necrotic yellow vein virus in escherichia coli].the heavy chains variable region gene (vh) of monoclonal antibody against beet necrotic yellow vein virus (bnyvv) was amplified from total dna extracted from anti-bnyvv hybridoma cells by pcr. sequencing showed that the vh belongs to mouse subgroup ii(a) and contains 360 bp, which code one hundred and twenty amino acids. the vh and vl genes were inserted into a plasmid which contains a linker sequence for constructing scfv gene. the new vector named ptc scfv. the scfv was produced in escherichia ...200011209682
improved detection of beet necrotic yellow vein virus in a das elisa by means of antibody single chain fragments (scfv) which were selected to protease-stable epitopes from phage display libraries.the detection of beet necrotic yellow vein virus (bnyvv) in stored sugar beets by means of monoclonal antibodies or antibody single chain fragments (scfv) often poses problems, because the immunodominant c-terminal epitope of the viral coat protein is readily lost due to proteolysis. clones which produce scfv specific for protease-stable bnyvv epitopes were selected from two naive phage display libraries. fusion proteins of the scfv with a human igg kappa chain (expressed from the newly designed ...200010664416
p42 movement protein of beet necrotic yellow vein virus is targeted by the movement proteins p13 and p15 to punctate bodies associated with plasmodesmata.cell-to-cell movement of beet necrotic yellow vein virus (bnyvv) is driven by a set of three movement proteins--p42, p13, and p15--organized into a triple gene block (tgb) on viral rna 2. the first tgb protein, p42, has been fused to the green fluorescent protein (gfp) and fusion proteins between p42 and gfp were expressed from a bnyvv rna 3-based replicon during virus infection. gfp-p42, in which the gfp was fused to the p42 n terminus, could drive viral cell-to-cell movement when the copy of t ...200010796018
structure and variability of the 3' end of rna 3 of beet soil-borne pomovirus--a virus with uncertain pathogenic effects.pcr products representing c. 550 3' terminal bases of beet soil-borne pomovirus (bsbv) rna 3 were compared for sources of this virus from all major sugarbeet-growing areas in germany. in none of these areas conspicious symptoms could be attributed to the presence of bsbv. single strand conformation polymorphism analyses suggested that the bsbv genome may be very variable. this was confirmed by nucleotide sequence analysis. each pcr product which was analysed showed sequence differences to others ...200010948990
molecular analyses of european a, b and p type sources of beet necrotic yellow vein virus and detection of the rare p type in kazakhstan.nucleotide sequence analyses revealed that the genomes of the various european types of beet necrotic yellow vein virus (bnyvv), i.e. the a, b and p types, are strongly conserved. almost identical sequences were found, for instance, for a types originating from the netherlands, italy and former yugoslavia; these sequences were also almost identical to those determined c. 15 years ago by bouzoubaa et al. (1985; 1986 and 1987). this sequence stability of bnyvv types is in contrast to a pronounced ...200011003469
detection and nucleotide analysis of rna5 of beet necrotic yellow vein virus isolated in china.using the rt-pcr method, five isolates of beet necrotic yellow vein virus from china were used for the rna5 genomic component detection and sequence analysis. the result showed that rna5 was only found in the isolates from baotou and hohhot, but not in those of xingjiang, helongjiang, and wulate of inner mongolia. the rna5 components had 1338 nucleotides and 1358 nucleotides in the length of baotou and hohhot isolates, respectively, in which the single open reading frame (orf) encoding for a pro ...199911037951
evidence for three groups of sequence variants of beet necrotic yellow vein virus rna 5.about half of japanese isolates of beet necrotic yellow vein virus (bnyvv) were found to contain rna 5 molecules, which were also detected in virus isolates from china and france. sequence comparisons of rna 5 (nucleotides 327 to 1171) in 25 isolates showed that there are up to 8% sequence differences, and that rna 5 variants fall into three groups: group i contains most of the japanese and chinese isolates, group ii two japanese isolates, and group iii four french isolates. the group i isolates ...199910416372
effects of structural modifications upon the accumulation in planta of replicons derived from beet necrotic yellow vein virus rna 3.beet necrotic yellow vein virus (bnyvv) rna 3 from which all but the 3' and 5' 'core' replication origins (promoters) have been deleted replicates when coinoculated to chenopodium quinoa with viral rnas 1 and 2. the resulting 'replicon' can be used to express inserted heterologous sequences in planta. the effects of alterations of replicon structure on its efficiency of accumulation in planta were examined. inclusion of up to approximately 240 nucleotides of sequence from the region immediately ...199910446653
rna 3 deletion mutants of beet necrotic yellow vein virus do not cause rhizomania disease in sugar beets.abstract two mutant strains of beet necrotic yellow vein virus (bnyvv) containing deletions in rna 3 were obtained by single lesion transfers in tetragonia expansa. the deleted regions encode either 94 or 121 amino acids toward the c-terminal part of the 25-kda protein (p25). wild-type and mutant virus strains were inoculated by polymyxa betae to sugar beet seedlings of susceptible and partially resistant cultivars. no differences were found in virus content in rootlets between mutant and wild-t ...199918944654
inheritance of resistance to beet necrotic yellow vein virus in beta vulgaris conferred by a second gene for resistance.rhizomania is a serious disease of sugar beet, caused by beet necrotic yellow vein virus (bnyvv). the disease can only be controlled by the use of resistant cultivars. the accession holly contains a single dominant gene for resistance, called rz. the identification of a locus for resistance that differs from rz would provide possibilities to produce cultivars with multiple resistance to bnyvv. inheritance of resistance to bnyvv was studied by screening progenies of crosses between resistant plan ...199922665213
the genome organization of the broad bean necrosis virus (bbnv).the genome of the broad bean necrosis virus oita-isolate (bbnv-o) [rna1 (6.0 kb), rna2 (2.8 kb) and rna3 (2.4 kb)] was cloned and sequenced. computer analysis indicates that methyltransferase, helicase and rna-dependent rna polymerase (rdrp) motifs are present in rna1. the viral capsid protein (cp) cistron is located at the 5' terminal end of rna2 and the mr of cp (20 k) is close to that determined by sds-page analysis. an ochre codon (uaa) in the cp cistron is thought to be partially suppressed ...19989722878
vascular movement of beet necrotic yellow vein virus in beta macrocarpa is probably dependent on an rna 3 sequence domain rather than a gene product.rnas 1 and 2 of beet necrotic yellow vein virus (bnyvv) carry the functions enabling viral rna replication, cell-to-cell movement, virus assembly and vascular movement of the virus in the systemic host spinacea oleracea. in beta macrocarpa, on the other hand, bnyvv rna 3 is required for vascular movement. replication-competent rna 3 transcripts carrying various point mutations and deletions were coinnoculated with rnas 1 and 2 to young leaves of b. macrocarpa and the ability of the virus to mult ...19989472625
cell-to-cell movement of beet necrotic yellow vein virus: i. heterologous complementation experiments provide evidence for specific interactions among the triple gene block proteins.cell-to-cell movement of beet necrotic yellow vein virus (bnyvv) requires three proteins encoded by a triple gene block (tgb) on viral rna 2. a bnyvv rna 3-derived replicon was used to express movement proteins to functionally substitute for the bnyvv tgb proteins was tested by coinoculation of tgb-defective bnyvv with the various replicons to chenopodium quinoa. trans-heterocomplementation was successful with the movement protein (p30) of tobacco mosaic virus but not with the tubule-forming mov ...19989650295
nicotiana benthamiana plants expressing beet necrotic yellow vein virus (bnyvv) coat protein-specific scfv are partially protected against the establishment of the virus in the early stages of infection and its pathogenic effects in the late stages of infection.transgenic plants of nicotiana benthamiana expressing single chain antibody fragments (scfv) specific for the coat protein of beet necrotic yellow vein virus (bnyvv) and non-expressing control plants were inoculated with bnyvv mechanically and by means of the vector polymyxa betae. the scfv were presumably expressed in the endoplasmic reticulum (er). the average time needed for infections to become detectable was longer in the scfv-expressing plants than in the non-expressing control plants. in ...19979672643
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