| soybean dwarf luteovirus contains the third variant genome type in the luteovirus group. | complementary dnas covering the entire rna genome of soybean dwarf luteovirus (sdv) were cloned and sequenced. computer analysis of the 5861 nucleotide sequence revealed five major open reading frames (orfs) possessing conservation of sequence and organisation with known luteovirus sequences. comparative analyses of the genome structure show that sdv shares sequence homology and features of gene organisation with barley yellow dwarf virus (pav isolate) in the 5' half of the genome, yet is more c ... | 1994 | 8291248 |
| control of start codon choice on a plant viral rna encoding overlapping genes. | the signals that control initiation of translation in plants are not well understood. to dissect some of these signals, we used a plant viral mrna on which protein synthesis initiates at two out-of-frame start codons. on the large subgenomic rna (sgrna1) of barley yellow dwarf virus-pav serotype, the coat protein (cp) and overlapping 17k open reading frames (orfs) are translated beginning at the first and second aug codons, respectively. the roles of bases at positions -3 and +4 relative to the ... | 1993 | 8329899 |
| effect of mutations in barley yellow dwarf virus genomic rna on the 5' termini of subgenomic rnas. | to investigate the role in transcription initiation of sequences upstream of the promoter for subgenomic rna2 (sgrna2) of barley yellow dwarf virus pav, deletion and insertion clones were constructed and the 5' termini of all three sgrnas were determined. deletion and insertion of sequences upstream of the transcription start site of sgrna2 altered the position and nucleotide used to initiate transcription of sgrna2, but not of sgrnas 1 or 3. since the promoter for sgrna2 is downstream of the mu ... | 2001 | 11556715 |
| comparison of complete nucleotide sequences of genomic rnas of four soybean dwarf virus strains that differ in their vector specificity and symptom production. | soybean dwarf virus (sbdv) is divided into four strains, namely ys, yp, ds and dp. ys and yp cause yellowing in soybeans, while ds and dp cause dwarfing. ys and ds are transmitted by aulacorthum solani, while yp and dp are transmitted by acyrthosiphon pisum. to clarify the taxonomic relationship between the four strains and to classify sbdv into an appropriate genus in the luteoviridae, we determined the complete nucleotide sequences of genomic rnas of four isolates belonging to each of the stra ... | 2001 | 11722012 |
| molecular diversity of the coat protein-encoding region of barley yellow dwarf virus-pav and barley yellow dwarf virus-mav from latvia and sweden. | the sequence variability of barley yellow dwarf virus-pav (pav) and barley yellow dwarf virus-mav (mav) was studied by comparing 502 nucleotides from the coat protein-encoding region of six isolates from latvia and four from sweden. the diversity within mav was low (>97% sequence identity), also when compared to isolates from usa and china. in contrast, the variability among pav isolates was greater and phylogenetic analysis including isolates of a wide geographic origin detected two major clust ... | 2004 | 15045570 |
| in situ localization of barley yellow dwarf virus-pav 17-kda protein and nucleic acids in oats. | abstract barley yellow dwarf virus strain pav (bydv-pav) rna and the 17-kda protein were localized in bydv-pav-infected oat cells using in situ hybridization and in situ immunolocalization assays, respectively. the in situ hybridization assay showed labeling of filamentous material in the nucleus, cytoplasm, and virus-induced vesicles with both sense and antisense nucleic acid probes, suggesting that the filamentous material found in bydv-pav-infected cells contains viral rna. bydv-pav negative- ... | 1998 | 18944814 |
| transmission of two viruses that cause barley yellow dwarf is controlled by different loci in the aphid, schizaphis graminum. | clonal populations of the aphid, schizaphis graminum, have been separated into biotypes based on host preference and their ability to overcome resistance genes in wheat. recently, several biotypes were found to differ in their ability to transmit one or more of the viruses that cause barley yellow dwarf disease in grain crops, and vector competence was linked to host preference. the genetics of host preference has been studied in s. graminum, but how this may relate to the transmission of plant ... | 2007 | 20302539 |
| pyramiding of ryd2 and ryd3 conferring tolerance to a german isolate of barley yellow dwarf virus-pav (bydv-pav-asl-1) leads to quantitative resistance against this isolate. | barley yellow dwarf virus (bydv) is an economically important pathogen of barley, which may become even more important due to global warming. in barley, several loci conferring tolerance to bydv-pav-asl-1 are known, e.g. ryd2, ryd3 and a quantitative trait locus (qtl) on chromosome 2h. the aim of the present study was to get information whether the level of tolerance against this isolate of bydv in barley can be improved by combining these loci. therefore, a winter and a spring barley population ... | 2011 | 21416402 |
| species composition of aphid vectors (hemiptera: aphididae) of barley yellow dwarf virus and cereal yellow dwarf virus in alabama and western florida. | yellow dwarf is a major disease problem of wheat, triticum aestivum l., in alabama and is estimated to cause yield loss of 21-42 bu/acre. the disease is caused by a complex of viruses comprising several virus species, including barley yellow dwarf virus-pav and cereal yellow dwarf virus-rpv. several other strains have not yet been classified into a specific species. the viruses are transmitted exclusively by aphids (hemiptera:aphididae). between the 2005 and 2008 winter wheat seasons, aphids wer ... | 2011 | 21882679 |
| barley yellow dwarf virus infection and elevated co2 alter the antioxidants ascorbate and glutathione in wheat. | plant antioxidants ascorbate and glutathione play an important role in regulating potentially harmful reactive oxygen species produced in response to virus infection. barley yellow dwarf virus is a widespread viral pathogen that systemically infects cereal crops including wheat, barley and oats. in addition, rising atmospheric co2 will alter plant growth and metabolism, including many potential but not well understood effects on plant-virus interactions. in order to better understand the wheat-b ... | 2016 | 27302010 |
| occurrence of viruses and associated grain yields of paired symptomatic and nonsymptomatic tillers in kansas winter wheat fields. | vector-borne virus diseases of wheat are recurrent in nature and pose significant threats to crop production worldwide. in the spring of 2011 and 2012, a state-wide sampling survey of multiple commercial field sites and university-managed kansas agricultural experiment station variety performance trial locations spanning all nine crop-reporting regions of the state was conducted to determine the occurrence of barley yellow dwarf virus-pav (bydv-pav), cereal yellow dwarf virus-rpv, wheat streak m ... | 2016 | 26799958 |
| environmental nutrient supply alters prevalence and weakens competitive interactions among coinfecting viruses. | the rates and ratios of environmental nutrient supplies can determine plant community composition. however, the effect of nutrient supplies on within-host microbial interactions is poorly understood. resource competition is a promising theory for understanding microbial interactions, because microparasites require nitrogen (n) and phosphorus (p) for synthesis of macromolecules such as nucleic acids and proteins. to better understand the effects of nutrient supplies to hosts on pathogen interacti ... | 2014 | 24975238 |
| the effect of elevated temperature on barley yellow dwarf virus-pav in wheat. | barley yellow dwarf virus-pav (bydv-pav) is associated with yellow dwarf disease, one of the most economically important diseases of cereals worldwide. in this study, the impact of current and future predicted temperatures for the wimmera wheat growing district in victoria, australia on the titre of bydv-pav in wheat was investigated. ten-day old wheat (triticum aestivum, cv. yitpi) seedlings were inoculated with bydv-pav and grown at ambient (5.0-16.1°c, night-day) or elevated (10.0-21.1°c, nig ... | 2014 | 24374266 |
| agrobacterium-mediated infection of whole plants by yellow dwarf viruses. | barley yellow dwarf virus-pav (bydv-pav) and cereal yellow dwarf virus-rpv (cydv-rpv) are only transmitted between host plants by aphid vectors and not by mechanical transmission. this presents a severe limitation for the use of a reverse genetics approach to analyze the effects of mutations in these viruses on plant infection and aphid transmission. here we describe the use of agroinfection to infect plants with bydv-pav and cydv-rpv. the cdnas corresponding to the complete rna genomes of bydv- ... | 2011 | 21763366 |
| dynamics of molecular evolution and phylogeography of barley yellow dwarf virus-pav. | barley yellow dwarf virus (bydv) species pav occurs frequently in irrigated wheat fields worldwide and can be efficiently transmitted by aphids. isolates of bydv-pav from different countries show great divergence both in genomic sequences and pathogenicity. despite its economical importance, the genetic structure of natural bydv-pav populations, as well as of the mechanisms maintaining its high diversity, remain poorly explored. in this study, we investigate the dynamics of bydv-pav genome evolu ... | 2011 | 21326861 |
| a single-stranded conformational polymorphism (sscp)-derived quantitative variable to monitor the virulence of a barley yellow dwarf virus-pav (bydv-pav) isolate during adaptation to the tc14 resistant wheat line. | a standardized single-stranded conformational polymorphism (sscp) procedure is proposed as an alternative to the time-consuming biological characterization of barley yellow dwarf virus-pav (bydv-pav) isolates. using this procedure, six of 21 overlapping regions used to scan the viral genome gave patterns specific to '4e' (avirulent) or '4t' ('4e'-derived virulent) isolates. the calibration of samples and integration of sscp patterns corresponding to the nucleotide region 1482-2023 allowed the es ... | 2010 | 20696003 |
| a single copy of a virus-derived transgene encoding hairpin rna gives immunity to barley yellow dwarf virus. | summary barley yellow dwarf virus-pav (bydv-pav) is the most serious and widespread virus of cereals worldwide. natural resistance genes against this luteovirus give inadequate control, and previous attempts to introduce synthetic resistance into cereals have produced variable results. in an attempt to generate barley with protection against bydv-pav, plants were transformed with a transgene designed to produce hairpin (hp)rna containing bydv-pav sequences. from 25 independent barley lines trans ... | 2000 | 20572982 |
| epidemiology and integrated management of persistently transmitted aphid-borne viruses of legume and cereal crops in west asia and north africa. | cool-season food legumes (faba bean, lentil, chickpea and pea) and cereals (bread and durum wheat and barley) are the most important and widely cultivated crops in west asia and north africa (wana), where they are the main source of carbohydrates and protein for the majority of the population. persistently transmitted aphid-borne viruses pose a significant limitation to legume and cereal production worldwide. surveys conducted in many countries in wana during the last three decades established t ... | 2009 | 19152820 |
| asymmetrical distribution of barley yellow dwarf virus pav variants between host plant species. | abstract a large epidemiological study of the genetic variation of barley yellow dwarf virus (bydv) serotype pav involving different host plant species was conducted. french bydv pav isolates were collected from barley and ryegrass, and their capsid protein gene sequences characterized using restriction fragment length polymorphism, single-strand conformation polymorphism, and sequence analyses. the data show that bydv pav isolates from five different continents are separated into two distinct g ... | 1998 | 18944888 |
| extreme reduction of disease in oats transformed with the 5' half of the barley yellow dwarf virus-pav genome. | abstract barley yellow dwarf viruses (bydvs) are the most serious and widespread viruses of oats, barley, and wheat worldwide. natural resistance is inadequate. toward overcoming this limitation, we engineered virus-derived transgenic resistance in oat. oat plants were transformed with the 5' half of the bydv strain pav genome, which includes the rna-dependent rna polymerase gene. in experiments on t2- and t3-generation plants descended from the same transformation event, all bydv-inoculated pla ... | 1998 | 18944812 |
| barley yellow dwarf virus and cereal yellow dwarf virus quantification by real-time polymerase chain reaction in resistant and susceptible plants. | abstract reliable detection and quantification of barley and cereal yellow dwarf viruses (ydvs) is a critical component in managing yellow dwarf diseases in small grain cereal crops. the method currently used is enzyme-linked immunosorbent assay (elisa), using antisera against the coat proteins that are specific for each of the various ydvs. recently, quantitative real-time reverse-transcription polymerase chain reaction (q-rt-pcr) has been used to detect bacterial and viral pathogens and to stu ... | 2003 | 18944066 |
| a chinese isolate of barley yellow dwarf virus-pav represents a third distinct species within the pav serotype. | the complete nucleotide sequence of barley yellow dwarf virus (bydv) pav-cn genomic rna was determined. this represents the seventh complete genome sequence of a bydv-pav serotype. the genome organization of pav-cn was comparable to that of other bydv-pav serotypes, but the nucleotide sequence of full genome was only 76.9-80.3% similar. sequence similarity of individual open reading frames and untranslated regions (utr) between pav-cn and other pav isolates ranged from 37.9 to 98.2%. overall, pa ... | 2007 | 17347769 |
| evaluation of oat cultivars and lines under infection with barley yellow dwarf virus. | thirteen domestic and foreign oat cultivars and eight breeding lines bred from the university of illinois were evaluated for resistance to barley yellow dwarf (byd) using artificial inoculation with rhopalosiphum padi viruliferous for an isolate of barley yellow dwarf virus-pav endemic to moscow region origin. cultivar blaze and six illinois lines showed the best grain yields under disease pressure that resembled a byd epidemic. | 2004 | 15756843 |
| improvement of barley yellow dwarf virus-pav detection in single aphids using a fluorescent real time rt-pcr. | one of the major factors determining the incidence of barley yellow dwarf virus (bydv) on autumn-sown cereals is the viruliferous state of immigrant winged aphids. this variable is assessed routinely using the enzyme-linked immunosorbant assay (elisa). however, the threshold for virus detection by elisa can lead to false negative results for aphids carrying less than 10(6) particles. although molecular detection techniques enabling the detection of lower virus quantities in samples are available ... | 2003 | 12757920 |
| nucleotide sequence shows that bean leafroll virus has a luteovirus-like genome organization. | the complete nucleotide sequence of the bean leafroll virus (blrv) genomic rna and the termini of its smallest subgenomic rnas were determined to better understand its mechanisms of gene expression and replication and its phylogenetic position within the luteoviridae: the number and placement of open reading frames (orfs) within the blrv genome was luteovirus-like. the nucleotide and predicted amino acid sequences of blrv were most similar to those of soybean dwarf virus (sbdv). phylogenetic ana ... | 2002 | 12075101 |
| biolistic-mediated inoculation of immature wheat embryos with barley yellow dwarf virus-pav. | successful mechanical inoculation of plant with viruses requires an efficient method to introduce the viral pathogen into the appropriate cells of the plant. barley yellow dwarf virus-pav (bydv-pav, luteovirus), transmitted naturally by aphids, must be inoculated into the phloem tissue to infect systemically inoculated hosts. the particle bombardment method used widely for nucleic acid transfer into plant tissues was adapted to inoculate immature embryos of winter and spring wheat cultivars with ... | 2002 | 11879704 |
| barley yellow dwarf virus-pav rna does not have a vpg. | the genus luteovirus is divided into two subgroups. it has already been shown that a genome-linked protein (vpg) is covalently attached to the 5'-end of the genomic rna of subgroup ii luteoviruses, but whether a vpg is present or absent on the genomic rna of subgroup i luteoviruses is unknown. in the present work, a simple and sensitive method was developed for the detection of the vpg on virion genomic rna. this method was used to show that a vpg is not attached to the 5'-end of the rna genome ... | 1997 | 9672612 |
| local and distant sequences are required for efficient readthrough of the barley yellow dwarf virus pav coat protein gene stop codon. | many viruses use stop codon readthrough as a strategy to produce extended coat or replicase proteins. the stop codon of the barley yellow dwarf virus (pav serotype) coat protein gene is read through at a low rate. this produces an extended polypeptide which becomes part of the virion. we have analyzed the cis-acting sequences in the barley yellow dwarf virus pav genome required for this programmed readthrough in vitro in wheat germ extracts and reticulocyte lysates and in vivo in oat protoplasts ... | 1996 | 8709208 |
| detection of the readthrough protein of barley yellow dwarf virus. | the single open reading frame (orf) 5 encoding the 50-kda protein of barley yellow dwarf virus pav-il (bydv-pav-il) was expressed in bacteria, purified, and used as an immunogen/antigen to produce/screen antibodies specific to the 50-kda protein. two monoclonal antibodies (mab pav-il-22 kda and mab pav-il-50 kda) raised against bydv-pav-il could specifically detect the presence of the 72-kda readthrough protein in extracts from the bydv-infected leaf tissue. the results suggest that orf 5 (50-kd ... | 1994 | 8030200 |
| a sequence located 4.5 to 5 kilobases from the 5' end of the barley yellow dwarf virus (pav) genome strongly stimulates translation of uncapped mrna. | an infectious, in vitro transcript from a full-length cdna clone of the barley yellow dwarf virus (pav serotype) genome translated efficiently in a wheat germ translation extract. deletions in a region that we call the 3' translational enhancer, located between bases 4,513 and 5,009 in the 5,677-base genome, reduced translation of the 5'-proximal open reading frames from uncapped rna by at least 30-fold. deletions elsewhere in all but the 5' end of the genome had no effect on translation. presen ... | 1995 | 7768947 |
| genes and cis-acting sequences involved in replication of barley yellow dwarf virus-pav rna. | deletion and point mutation analyses were employed to determine gene products and cis-acting signals involved in translation, replication, and encapsidation of barley yellow dwarf virus (pav serotype) rna in oat protoplasts. of the six open reading frames (orfs), only orfs 1 and 2, which include the putative rna-dependent rna polymerase gene, were required for replication. in vitro translation of these mutants revealed that sequence upstream of the shifty heptanucleotide was required for ribosom ... | 1995 | 7676628 |
| translational frameshifting mediated by a viral sequence in plant cells. | it has been proposed that the polymerase gene of barley yellow dwarf virus and related viruses is expressed by a ribosomal frameshift event during translation. the 5' end of this gene overlaps with the 3' end of an upstream gene that is in a different reading frame. the region of overlap is similar to sequences in retro- and coronaviruses that are known to express their polymerase genes by frameshifting. this overlap region includes a "shifty" heptanucleotide, followed by a highly structured reg ... | 1992 | 1549592 |
| distribution of barley yellow dwarf virus-pav in the sub-antarctic kerguelen islands and characterization of two new luteovirus species. | a systematic search for viral infection was performed in the isolated kerguelen islands, using a range of polyvalent genus-specific pcr assays. barley yellow dwarf virus (bydv) was detected in both introduced and native grasses such as poa cookii. the geographical distribution of bydv and its prevalence in p. cookii were analyzed using samples collected from various sites of the archipelago. we estimate the average prevalence of bydv to be 24.9% in p. cookii, with significant variability between ... | 2013 | 23825645 |
| variation in the transmission of barley yellow dwarf virus-pav by different sitobion avenae clones in china. | fourteen sitobion avenae fabricius (hemiptera: aphididae) clonal lines (clones) originating from china were tested for their ability to transmit bydv-pav (one isolate from belgium and another from china) using wheat plants. by sequence analysis, the coat protein gene of bydv-pav-be was distinguishable from bydv-pav-cn. all of the clones could transmit bydv-pav, and the transmission varied from 24.42% to 66.67% with bydv-pav-be and from 23.55% to 56.18% with bydv-pav-cn. these data suggest that s ... | 2013 | 23911295 |
| viral pathogen production in a wild grass host driven by host growth and soil nitrogen. | nutrient limitation is a basic ecological constraint that has received little attention in studies on virus production and disease dynamics. nutrient availability could directly limit the production of viral nucleic acids and proteins, or alternatively limit host growth and thus indirectly limit metabolic pathways necessary for viral replication. in order to compare direct and indirect effects of nutrient limitation on virus production within hosts, we manipulated soil nitrogen (n) and phosphoru ... | 2015 | 25782030 |
| methodological guidelines for accurate detection of viruses in wild plant species. | ecological understanding of disease risk, emergence, and dynamics and of the efficacy of control strategies relies heavily on efficient tools for microorganism identification and characterization. misdetection, such as the misclassification of infected hosts as healthy, can strongly bias estimates of disease prevalence and lead to inaccurate conclusions. in natural plant ecosystems, interest in assessing microbial dynamics is increasing exponentially, but guidelines for detection of microorganis ... | 2016 | 26773088 |
| differential impacts of virus diversity on biomass production of a native and an exotic grass host. | pathogens are common and diverse in natural communities and have been implicated in the success of host invasions. yet few studies have experimentally measured how pathogens impact native versus exotic hosts, particularly when individual hosts are simultaneously coinfected by diverse pathogens. to estimate effects of interactions among multiple pathogens within host individuals on both transmission of pathogens and fitness consequences for hosts, we conducted a greenhouse experiment using califo ... | 2015 | 26230720 |