Publications
| Title | Abstract | Year(sorted descending) Filter | PMID Filter |
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| characterisation of potato virus y isolates from iran. | a survey of potato virus y (pvy) was conducted in cultivated fields in six iranian provinces between january 2005 to july 2007. two hundred samples from potato and tomato were collected and analyzed by enzyme-linked immunosorbent assay (elisa) for potyviruses. almost one fourth of the samples were found to be infected by pvy. analysis of these pvy-positive samples using three monoclonal antibodies (mabs) facilitating the simultaneous detection of three main strains namely the ordinary (pvy(o)), ... | 2010 | 21082231 |
| ecotilling in capsicum species: searching for new virus resistances. | the ecotilling technique allows polymorphisms in target genes of natural populations to be quickly analysed or identified and facilitates the screening of genebank collections for desired traits. we have developed an ecotilling platform to exploit capsicum genetic resources. a perfect example of the utility of this ecotilling platform is its application in searching for new virus-resistant alleles in capsicum genus. mutations in translation initiation factors (eif4e, eif(iso)4e, eif4g and eif(is ... | 2010 | 21073716 |
| preliminary survey of potato virus y (pvy) strains in potato samples from kurdistan (iran). | potato virus y (pvy) is the type species in the potyvirus genus of the family potyviridae. this plant pathogenic virus is transmitted through plant sap inoculation by stem and core grafting and by at least 25 aphid species in a non-persistent manner. according to potato specialists in most parts of the world, pvy is currently considered as the most harmful virus in cultivated potatoes. this is also the case for potato production in iran. in this project we investigated potato leaves that were co ... | 2010 | 21534491 |
| localisation of hydrogen peroxide accumulation during solanum tuberosum cv. rywal hypersensitive response to potato virus y. | the reactive oxygen species hydrogen peroxide (h(2)o(2)) was detected cytochemically in solanum tuberosum cv. rywal tissues as a hypersensitive response (hr) 24 and 48 h after a potato virus y (pvy) infection. hydrogen peroxide was detected in vivo by its reaction with 3.3-diaminobenzidine, producing a reddish-brown staining in contact with h(2)o(2). hydrogen peroxide was detected in the necrotic area of the epidermal and mesophyll cells 24 and 48 h after the pvy infection. highly localised accu ... | 2010 | 20117938 |
| an induced mutation in tomato eif4e leads to immunity to two potyviruses. | the characterization of natural recessive resistance genes and arabidopsis virus-resistant mutants have implicated translation initiation factors of the eif4e and eif4g families as susceptibility factors required for virus infection and resistance function. | 2010 | 20593023 |
| ghmpk7, a novel multiple stress-responsive cotton group c mapk gene, has a role in broad spectrum disease resistance and plant development. | mitogen-activated protein kinase (mapk) cascades play a pivotal role in environmental responses and developmental processes in plants. previous researches mainly focus on the mapks in groups a and b, and little is known on group c. in this study, we isolated and characterized ghmpk7, which is a novel gene from cotton belonging to the group c mapk. rna blot analysis indicated that ghmpk7 transcript was induced by pathogen infection and multiple defense-related signal molecules. transgenic nicotin ... | 2010 | 20602149 |
| identification of a novel npr1-like gene from nicotiana glutinosa and its role in resistance to fungal, bacterial and viral pathogens. | the npr1 or npr1-like genes play a pivotal role in systemic acquired resistance in plants. here, we isolated and identified a novel tobacco (nicotiana glutinosa) npr1-like gene (designated as ngnpr3). the full-length cdna is 2049 bp in length with a 1767 bp open reading frame which encodes a 588 amino acids protein with an estimated molecular mass of 66 kda and a calculated pi of 7.14. homology analysis suggested that the ngnpr3 protein shares significant similarity to atnpr3 of arabidopsis. tra ... | 2010 | 20653885 |
| cellular localisation of calcium ions during potato hypersensitive response to potato virus y. | ca(2+) is one of the most universal and versatile signalling molecules and is involved in almost every aspect of cellular processes. accumulating evidence suggests that ca(2+) serves as a messenger in many growth and developmental processes and in plant responses to biotic and abiotic stresses. numerous signals have been shown to induce transient elevation of cytoplasmic [ca(2+)](cyt) in plants. the calcium free ions were detected cytochemically in solanum tuberosum cv. rywal tissues as a hypers ... | 2010 | 21227706 |
| immunological detection of bean common mosaic virus in french bean (phaseolus vulgaris l.) leaves. | bean common mosaic potyvirus (bcmv) is an important seed borne pathogen of french bean. differential inoculation with bean common mosaic virus at cotylodonary trifoliate leaf stage and pre-flowering stage of crop growth revealed that cotyledonary leaf infection favored maximum disease expression. under immunosorbent electron microscopy (isem) the virus particles of filamentous structure having a diameter of 750 nm (l) and 15 nm (w) were observed. these particles gave positive precipitin tests wi ... | 2010 | 23100839 |
| characterization of the multiple resistance traits of somatic hybrids between solanum cardiophyllum lindl. and two commercial potato cultivars. | interspecific somatic hybrids between commercial cultivars of potato solanum tuberosum l. agave and delikat and the wild diploid species solanum cardiophyllum lindl. (cph) were produced by protoplast electrofusion. the hybrid nature of the regenerated plants was confirmed by flow cytometry, simple sequence repeat (ssr), amplified fragment length polymorphism (aflp), microsatellite-anchored fragment length polymorphism (mflp) markers and morphological analysis. somatic hybrids were assessed for t ... | 2010 | 20703881 |
| hc-pro, a potyvirus rna silencing suppressor, cancels cycling of cucumber mosaic virus in nicotiana benthamiana plants. | the mixed infection of cucumber mosaic virus (cmv) and a potyvirus has been known to increase cmv titer in nicotiana benthamiana plants, resulting in synergistic viral symptoms. we found that among three potyviruses--potato virus y (pvy), turnip mosaic virus (tumv), and clover yellow vein virus (c1yvv)--synergistic effects on cmv (or a recombinant cmv vector) titers were most efficiently induced by a co-infection with pvy in n. benthamiana plants. in addition, the helper component-proteinase (hc ... | 2010 | 20162445 |
| the simultaneous differentiation of potato virus y strains including the newly described strain pvy(ntn-nw) by multiplex pcr assay. | new recombinant strain and genotype of pvy, designated as pvy(ntn-nw) and syr-iii, respectively, shared properties with pvy(ntn) and pvy(n)w has been reported recently. pvy(ntn-nw) predominated in potato fields in syria and was able to induce potato tuber necrotic ringspot disease (ptnrd). due to the rapid spread of the recombinant strains of pvy which might be the case of pvy(ntn-nw), a specific and reliable detection method is an essential step to control this strain and minimize its spread. t ... | 2010 | 20025905 |
| a new lineage sheds light on the evolutionary history of potato virus y. | potato virus y (pvy) is one of the rare plant viruses for which some biological traits (host range and symptomatology) are highly correlated with phylogeny, allowing the reconstruction of the evolutionary history of these traits. in this article, a new lineage of pvy isolates from chile is described, showing unique genomic and biological properties. this lineage was found to be the sister group of all other pvy isolates and helped in the reconstruction of the ancestral traits and evolutionary hi ... | 2010 | 20078785 |
| 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 ... | 2010 | 20437276 |
| a point mutation in the polymerase of potato virus y confers virulence toward the pvr4 resistance of pepper and a high competitiveness cost in susceptible cultivar. | to understand why the pvr4 resistance of pepper against potyvirus spp. remained durable in field conditions while virulent potato virus y (pvy) variants could be selected in the laboratory, we studied the molecular mechanisms which generated these variants and the consequences on viral fitness. using a reverse genetics approach with an infectious cdna clone of pvy, we found that the region coding for the nib protein (rna-dependent rna polymerase) of pvy was the avirulence factor corresponding to ... | 2010 | 20459321 |
| oligonucleotide microarray-based detection and identification of 10 major tomato viruses. | a dna microarray chip was developed for screening 10 major economically important tomato viruses from infected plants using "combimatrix" platform 40-mer oligonucleotide probes. a total of 279 oligonucleotide virus probes were specific for simultaneous multiple detection, identification, differentiation and/or genotyping of each of the following tomato rna viruses and/or strains and a virus satellite: cucumber mosaic virus, cucumber mosaic virus satellite rna, tomatoinfectiouschlorosisvirus, tom ... | 2010 | 20470828 |
| expression of g-ry derived from the potato (solanum tuberosum l.) increases pvy(o) resistance. | in solanaceae, potato virus y(o) (pvy(o)) is a widespread virus leading to severe damages such as necrosis, molting, and yield reduction. the resistance y gene (ry gene) of potato specifically confers resistance to pvy infection. previously, potatoes resistant to pvy(o) infection were screened among the 32 korean cultivars. 'golden valley' displayed the most resistance to pvy(o) infection. 'golden valley''s ry gene (g-ry) was cloned from 'golden valley', and the function was investigated. g-ry p ... | 2010 | 20481626 |
| 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 ... | 2010 | 20517623 |
| effect of potato virus y on the nadp-malic enzyme from nicotiana tabacum l.: mrna, expressed protein and activity. | the effect of biotic stress induced by viral infection (potato virus y, strain ntn and o) on nadp-malic enzyme (ec 1.1.1.40) in tobacco plants (nicotiana tabacum l., cv. petit havana, sr1) was tested at the transcriptional, translational and activity level. the increase of enzyme activity in infected leaves was correlated with the increased amount of expressed protein and with mrna of cytosolic nadp-me isoform. transcription of the chloroplastic enzyme was not influenced by viral infection. the ... | 2009 | 20111689 |
| pvy(ntn) elicits a diverse gene expression response in different potato genotypes in the first 12 h after inoculation. | host gene expression changes in the early response to potato virus y(ntn) interaction were compared in two differently sensitive potato cultivars: the resistant cultivar santé and the sensitive cultivar igor. hybridization of potato tigr cdna microarrays allowed us to monitor the expression of approximately 10,000 genes simultaneously at 0.5 and 12 h post-inoculation (hpi). microarray data, analysed by statistics and data mining, were complemented by subtraction library construction and sequence ... | 2009 | 19236574 |
| occurrence and distribution of potato virus y strain n (pvy(n)) on celery in iran. | celery (apium graveolens) is an important crop grown in many countries. different types of diseases present a major constraint to celery production and can lead to significant reductions in yield potato virus y, the type member of the genus potyvirus(family potyviridae) is one of the causal agents of viral diseases in crops. in the present study, pvy occurring in celery fields was determined as the causal agent of mosaic disease of celery (apium graveolens). the virus is naturally transmitted by ... | 2009 | 20222571 |
| [a study on the mechanism of copper-induced resistance to potato virus y-vein necrosis strain (pvy(n)) in tobacco]. | in order to reveal the induced resistance mechanism of tobacco treated with copper solution to potato virus y-vein necrosis strain (pvy(n)), disease indexes, contents of virus and some physiological and biochemical indexes in tobacco were studied. the results showed that when treated at the copper concentration of 0.8 mg x l(-1), the symptom displayed and vein necrosis on tobacco were postponed, the disease index and content of virus sharply decreased , and the content of chlorophyll a, chloroph ... | 2009 | 19634767 |
| transcriptional changes and oxidative stress associated with the synergistic interaction between potato virus x and potato virus y and their relationship with symptom expression. | many virus diseases of economic importance to agriculture result from mixtures of different pathogens invading the host at a given time. this contrasts with the relatively scarce studies available on the molecular events associated with virus-host interactions in mixed infections. compared with single infections, co-infection of nicotiana benthamiana with potato virus x (pvx) and potato virus y (pvy) resulted in increased systemic symptoms (synergism) that led to necrosis of the newly emerging l ... | 2009 | 19810812 |
| the acquisition of molecular determinants involved in potato virus y necrosis capacity leads to fitness reduction in tobacco plants. | the prevalence of necrotic potato virus y (pvy) in natural populations could reflect increased fitness of necrotic isolates. in this paper, the effects of the acquisition of molecular determinants (a/g(2213) and a/c(2271)) involved in necrosis capacity on both the number of progeny produced and the competitiveness of pvy were characterized. the relationship between necrosis and fitness was tested using (i) nicotiana tabacum cv. xanthi and nicotiana clevelandii, (ii) necrotic pvy(n)-605 and non-n ... | 2009 | 19088295 |
| ngrdr1, an rna-dependent rna polymerase isolated from nicotiana glutinosa, was involved in biotic and abiotic stresses. | the rna-dependent rna polymerases (rdrs) play a key role in rna silencing, heterochromatin formation and natural gene regulation. here, a novel rdr gene was isolated from nicotiana glutinosa, designated as ngrdr1. the full-length cdna of ngrdr1 encodes a 1117-amino acid protein which harbors the five conserved regions in plant rdrs, including the most remarkable motif dbdgd (b is a bulky residue). amino acid sequence alignment revealed that ngrdr1 exhibited a high degree of identity with other h ... | 2009 | 19231228 |
| durability of plant major resistance genes to pathogens depends on the genetic background, experimental evidence and consequences for breeding strategies. | * the breakdown of plant resistance by pathogen populations is a limit to the genetic control of crop disease. polygenic resistance is postulated as a durable alternative to defeated major resistance genes. here, we tested this postulate in the pepper-potato virus y interaction. * the virus was selected for virulence towards monogenic and polygenic host resistance, using serial inoculations in laboratory and in natural epidemic conditions. the frequency of resistance breakdown and the genetic ch ... | 2009 | 19344475 |
| presence of necrotic strains of potato virus y in mexican potatoes. | as part of a routine screening for the possible presence of the necrotic strains of potato virus y affecting potatoes in mexico, five pvy isolates were submitted to biological and molecular analysis. considering their serological properties, two belong to the common strain (o) and three to the necrotic strain (n). all the isolates induced vein necrosis in nicotiana tabacum. to characterize the isolates, 5' ntr and p1 genes were sequenced and compared with sequences from genbank database. nucleot ... | 2009 | 19419565 |
| a novel recombinant strain of potato virus y suggests a new viral genetic determinant of vein necrosis in tobacco. | a novel potato virus y (pvy) isolate, l26, recovered from a frontier potato line was initially typed as a pvy(ntn) strain using multiplex rt-pcr and serological assays. however, l26 induced mosaic and mild vein clearing symptoms in tobacco rather than vein necrosis characteristic of the pvy (ntn) strain. the whole genome sequence was determined for l26 and two other pvy(ntn) isolates, hr1 and n4, from idaho that did induce vein necrosis in tobacco. the sequence of all three isolates was similar ... | 2009 | 19463723 |
| expression of potato virus y cytoplasmic inclusion protein in tobacco results in disorganization of parenchyma cells, distortion of epidermal cells, and induces mitochondrial and chloroplast abnormalities, formation of membrane whorls and atypical lipid accumulation. | infection of plant cells by potyviruses induces the formation of cytoplasmic inclusions ranging in size from 200 to 1000 nm. to determine if the ability to form these ordered, insoluble structures is intrinsic to the potyviral cytoplasmic inclusion protein, we have expressed the cytoplasmic inclusion protein from potato virus y in tobacco under the control of the chrysanthemum ribulose-1,5-bisphosphate carboxylase small subunit promoter, a highly active, green tissue promoter. no cytoplasmic inc ... | 2009 | 19477654 |
| molecular characterization and detection of recombinant isolates of potato virus y from china. | although potato virus y (pvy) is one of the most economically important pathogens of potatoes in china, few studies have been carried out to characterize the virus in that country. using reverse transcription-polymerase chain reaction (rt-pcr)-based genotyping developed previously, two types of recombinant pvy were identified in china for the first time. one resembled the european (eu) type of potato tuber necrosis strain (eu-pvy(ntn)), possessing three widely recognized recombinant joints (rjs ... | 2009 | 19597695 |
| the influence of rna-dependent rna polymerase 1 on potato virus y infection and on other antiviral response genes. | the gene encoding rna-dependent rna polymerase 1 (rdr1) is involved in basal resistance to several viruses. expression of the rdr1 gene also is induced in resistance to tobacco mosaic virus (tmv) mediated by the n gene in tobacco (nicotiana tabacum cv. samsun nn) in an incompatible hypersensitive response, as well as in a compatible response against potato virus y (pvy). reducing the accumulation of ntrdr1 transcripts by rna inhibition mediated by transgenic expression of a double-stranded rna h ... | 2009 | 19737104 |
| broomrape can acquire viruses from its hosts. | broomrapes (phelipanche, formerly orobanche) are parasitic plants that physically connect with the vascular systems of their hosts through haustorial structures. in this study, we found that cucumber mosaic virus (cmv), tomato mosaic virus (tomv), potato virus y (pvy), and tomato yellow leaf curl virus (tylcv) translocate from infected host plants to phelipanche aegyptiaca. in order to examine whether these viruses, and specifically cmv, replicate in the parasite, we tested several replication p ... | 2009 | 19821737 |
| an assessment of molecular variability and recombination patterns in south african isolates of potato virus y. | the coat protein (cp) gene of 75 south african potato virus y (pvy) isolates was amplified using reverse-transcriptase polymerase chain reaction (rt-pcr). the resulting cdna products were cloned and sequenced. these sequences were used to identify the strains to which the isolates belonged. some, when compared to reference sequences, belonged to the pvy(n) and pvy(o) strains. a number of isolates were found to demonstrate significant homology to pvy(n) strains from china. a large number of south ... | 2009 | 19862472 |
| crop border and mineral oil sprays used in combination as physical control methods of the aphid-transmitted potato virus y in potato. | the objectives of this work were to determine if the control of potato virus y (pvy, genus potyvirus, family potyviridae) in seed potato could be improved by combining border crops and mineral oil sprays, and if the border crop acts as a barrier or a virus sink. | 2009 | 19039809 |
| post-transcriptional gene silencing and virus resistance in nicotiana benthamiana expressing a grapevine virus a minireplicon. | grapevine virus a (gva) is closely associated with the economically important rugose-wood disease of grapevine. in an attempt to develop gva resistance, we made a gfp-tagged gva-minireplicon and utilized it as a tool to consistently activate rna silencing. launching the gva-minireplicon by agroinfiltration delivery resulted in a strong rna silencing response. in light of this finding, we produced transgenic nicotiana benthamiana plants expressing the gva-minireplicon, which displayed phenotypes ... | 2009 | 18821075 |
| a stable cytosolic expression of vh antibody fragment directed against pvy nia protein in transgenic potato plant confers partial protection against the virus. | the expression of recombinant antibodies in transgenic plants has been proved to be an efficient approach for large-scale production. however, the stability of these molecules and their accumulation level depend on their molecular properties and cellular targeting. the expression of single-domain antibody fragment (vh) can be advantageous since it offers small length, high expression, solubility and stability. it can therefore be preferred to other antibody derivatives avoiding the expression di ... | 2009 | 26493138 |
| development of a short oligonucleotide microarray for the detection and identification of multiple potyviruses. | the genus potyvirus is the largest and one of the most economically important virus genera infecting plants. however, current diagnostic techniques are limited in their ability to identify multiple potyvirus infections. an assay that can identify multiple potyviruses simultaneously, with good specificity and sensitivity, is therefore highly desirable. to determine the feasibility of simultaneous detection of multiple potyviruses a 25-mer oligonucleotide microarray was developed targeting four di ... | 2009 | 19654025 |
| sequence characteristics of potato virus y recombinants. | potato virus y (pvy) is one of the most economically important plant pathogens. the pvy genome has a high degree of genetic variability and is also subject to recombination. new recombinants have been reported in many countries since the 1980s, but the origin of these recombinant strains and the physical and evolutionary mechanisms driving their emergence are not clear at the moment. the replicase-mediated template-switching model is considered the most likely mechanism for forming new rna virus ... | 2009 | 19692546 |
| transient expression of homologous hairpin rna interferes with pvy transmission by aphids. | hairpin rnas have been used to confer resistance to viruses in plants through rna silencing. however, it has not been demonstrated that rna silencing was effective against inoculation by aphids of non-persistently transmitted viruses, the major route of plant virus spread in nature. as a proof-of-principle strategy, we made use of agrobacterium tumefaciens to transiently express a hairpin rna homologous to potato virus y (pvy) in plant tissues. a complete and specific interference with aphid tra ... | 2008 | 18353170 |
| natural variation and functional analyses provide evidence for co-evolution between plant eif4e and potyviral vpg. | amino acid substitutions in the eukaryotic translation initiation factor 4e (eif4e) result in recessive resistance to potyviruses in a range of plant species, including capsicum spp. correspondingly, amino acid changes in the central part of the viral genome-linked protein (vpg) are responsible for the potyvirus's ability to overcome eif4e-mediated resistance. a key observation was that physical interaction between eif4e and the vpg is required for viral infection, and eif4e mutations that cause ... | 2008 | 18182024 |
| a role for inositol hexakisphosphate in the maintenance of basal resistance to plant pathogens. | phytic acid (myo-inositol hexakisphosphate, insp6) is an important phosphate store and signal molecule in plants. however, low-phytate plants are being developed to minimize the negative health effects of dietary insp6 and pollution caused by undigested insp6 in animal waste. insp6 levels were diminished in transgenic potato plants constitutively expressing an antisense gene sequence for myo-inositol 3-phosphate synthase (ips, catalysing the first step in insp6 biosynthesis) or escherichia coli ... | 2008 | 18643983 |
| complementary functions of two recessive r-genes determine resistance durability of tobacco 'virgin a mutant' (vam) to potato virus y. | tobaccos vam and nc745 carry the recessive va gene that confers resistance to pvy(nn). however, they exhibit different levels of resistance durability. upon virus inoculation, only nc745 developed sporadic systemic symptoms caused by emerging resistance-breaking variants that easily infected both nc745 and vam genotypes. to identify the differential host conditions associated with this phenomenon, cellular accumulation, cell-to-cell movement, vascular translocation, and foliar content of pvy(nn) ... | 2008 | 18682305 |
| estimation of the effective number of founders that initiate an infection after aphid transmission of a multipartite plant virus. | the fecundity of rna viruses can be very high. thus, it is often assumed that viruses have large populations, and rna virus evolution has been mostly explained using purely deterministic models. however, population bottlenecks during the virus life cycle could result in effective population numbers being much smaller than reported censuses, and random genetic drift could be important in virus evolution. a step at which population bottlenecks may be severe is host-to-host transmission. we report ... | 2008 | 18842732 |
| single-step rt real-time pcr for sensitive detection and discrimination of potato virus y isolates. | potato virus y (pvy) has a worldwide distribution and infects several economically important crops from the solanaceae family. the emergence and spread of the pvyntn strain, which is the causative agent of potato tuber necrotic ringspot disease (ptnrd), has lead to large economic losses and highlighted the need for accurate discrimination of the different pvy strains. detection and differentiation of pvy isolates is mainly based on a combination of elisa, rt-pcr and bioassays; however, pvyntn is ... | 2008 | 18328576 |
| multiplex microsphere immuno-detection of potato virus y, x and plrv. | to monitor seed potatoes for potato virus x, y and plrv, a multiplex microsphere immunoassay (mia) was developed based on the luminex xmap technology, as an alternative to elisa. the xmap technology allowed detection of a number of antigens simultaneously whereas elisa only allowed simplex detection of antigens. the use of paramagnetic beads in the mia procedure allowed efficient removal of excess sample compounds and reagents. this resulted in lower background values and a higher specificity th ... | 2008 | 18329108 |
| transient expression of hpv16 e7 peptide (aa 44-60) and hpv16 l2 peptide (aa 108-120) on chimeric potyvirus-like particles using potato virus x-based vector. | the optimized expression of recombinant potato virus a coat protein (acp) carrying two different epitopes from human papillomavirus type 16 (hpv16) was developed. epitope derived from minor capsid protein l2 was expressed as n-terminal fusion with acp while an epitope derived from e7 oncoprotein was fused to its c-terminus. the construct was cloned into potato x potexvirus (pvx) based vector and transiently expressed in plants using agrobacterium tumefaciens mediated inoculation. to increase the ... | 2008 | 17980618 |
| phenotypes and functional effects caused by various viral rna silencing suppressors in transgenic nicotiana benthamiana and n. tabacum. | rna silencing suppressor genes derived from six virus genera were transformed into nicotiana benthamiana and n. tabacum plants. these suppressors were p1 of rice yellow mottle virus (rymv), p1 of cocksfoot mottle virus, p19 of tomato bushy stunt virus, p25 of potato virus x, hcpro of potato virus y (strain n), 2b of cucumber mosaic virus (strain kin), and ac2 of african cassava mosaic virus (acmv). hcpro caused the most severe phenotypes in both nicotiana spp. ac2 also produced severe effects in ... | 2008 | 18184062 |
| ne-11 represents a new strain variant class of potato virus y. | this report describes the characterization by whole-genome sequencing of four pvy isolates with unique combinations of molecular and symptomatic characteristics. three of these four isolates were of type pvy(n:o) (id-1, or-1, pn10a), including one of "type b", which contains an extra recombination event in the 5'utr/p1 cistron; the other (ne-11) represents a novel pvy molecular genotype, previously misclassified as a pvy(na-ntn) isolate. the full genome sequence of this latter isolate is unique ... | 2008 | 18193154 |
| novel somatic hybrids (solanum tuberosum l.+solanum tarnii) and their fertile bc1 progenies express extreme resistance to potato virus y and late blight. | solanum tarnii, a wild diploid, tuber-bearing mexican species belonging to the series pinnatisecta is highly resistant to potato virus y (pvy) and colorado potato beetle and shows a strong hypersensitive reaction to phytophthora infestans. therefore, it could be a potential source of resistance to pathogens for potato breeders. s. tarnii (2n=2x=24) is reproductively isolated from tetraploid solanum tuberosum and hence difficult to include in potato breeding programmes. in this study, interspecif ... | 2008 | 18202839 |
| lettuce mosaic virus: from pathogen diversity to host interactors. | taxonomy: lettuce mosaic virus (lmv) belongs to the genus potyvirus (type species potato virus y) in the family potyviridae. physical properties: the virion is filamentous, flexuous with a length of 750 nm and a width of 15 nm. the particles are made of a genomic rna of 10 080 nucleotides, covalently linked to a viral-encoded protein (the vpg) at the 5' end and with a 3' poly a tail, and encapsidated in a single type of capsid protein. the molecular weight of the capsid protein subunit has been ... | 2008 | 18705846 |
| quantitative pcr measurements of the effects of introducing inosines into primers provides guidelines for improved degenerate primer design. | polymerase chain reaction (pcr) is used to detect groups of viruses with the use of group-specific degenerate primers. inosine residues are sometimes used in the primers to match variable positions within the complementary target sequences, but there is little data on their effects on cdna synthesis and amplification. a quantitative reverse-transcription pcr was used to measure the rate of amplification with primers containing inosine residues substituted at different positions and in increasing ... | 2008 | 18760305 |
| [one-step cytometric bead array for rapid detection of potato virus a]. | based on immunoassay, we developed a method to detect potato virus a (pva) using one-step cytometric bead array (cba). | 2008 | 18479067 |
| antibodies to potato virus y bind the amyloid beta peptide: immunohistochemical and nmr studies. | studies in transgenic mice bearing mutated human alzheimer disease (ad) genes show that active vaccination with the amyloid beta (abeta) protein or passive immunization with anti-abeta antibodies has beneficial effects on the development of disease. although a trial of abeta vaccination in humans was halted because of autoimmune meningoencephalitis, favorable effects on abeta deposition in the brain and on behavior were seen. conflicting results have been observed concerning the relationship of ... | 2008 | 18505725 |
| rna silencing-mediated resistance is related to biotic / abiotic stresses and cellular rdrp expression in transgenic tobacco plants. | the discovery of rna silencing inhibition by virus encoded suppressors or low temperature leads to concerns about the stability of transgenic resistance. rna-dependent rna polymerase (rdrp) has been previously characterized to be essential for transgene-mediated rna silencing. here we showed that low temperature led to the inhibition of rna silencing, the loss of viral resistance and the reduced expression of host rdrp homolog (ntrdrp1) in transgenic t4 progeny with untranslatable potato virus y ... | 2008 | 18510868 |
| a new combination of rna-mediated dna ligation and on-chip elongation for detecting viral rna. | we describe a novel method that combines rna-mediated dna ligation and on-chip elongation for detecting viral rna. these virus species-specific detection probes (dps) were designed to match sequences of the "target" virus and then chemically synthesized into 2 parts. if the target virus exists, 2 parts of the dp can be ligated by t4 dna ligase. the ligated dp was hybridized to its corresponding capture probe (cp) on a dna array. then, an on-chip dna polymerization (including cy3-dutp) was perfor ... | 2008 | 18513911 |
| the ngaox1a gene cloned from nicotiana glutinosa is implicated in the response to abiotic and biotic stresses. | a novel gene, named ngaox1a, was isolated from nicotiana glutinosa by rt-pcr (reverse transcription-pcr). the full-length cdna of ngaox1a was 1448 bp, including a 1062-bp orf (open reading frame), a 124 bp 5' utr (untranslated region) and a 262 bp 3' utr. the orf encodes a 353-amino-acid protein which contains two conserved cysteine residues, four iron-binding motifs, five alpha-helix regions and six conserved histidine residues. the phylogenetic tree showed that ngaox1a belongs to the aox1 (alt ... | 2008 | 18588517 |
| behavior of bird cherry-oat aphid and green peach aphid in relation to potato virus y transmission. | potato virus y is transmitted to potato in a nonpersistent manner by many aphid species, some of which do not colonize this crop. the behavior of bird cherry-oat aphid, rhopalosiphum padi (l.) on potato, solanum tuberosum l., a plant species that is not colonized by this aphid, was described and compared with that of the potato-colonizing green peach aphid, myzuspersicae (sulzer). a higher proportion of winged morph of r. padi than m. persicae left the plant, but aphids that stayed in contact wi ... | 2008 | 18613572 |
| production of polyclonal antibodies to a recombinant coat protein of potato virus y. | the gene encoding the coat protein (cp) of a potato virus y (pvy) was cloned into expression vector pmpm-a4omega. pvy cp was expressed in escherichia coli and the purified recombinant protein was used for raising rabbit polyclonal antibodies. the sera and antibodies were tested for the detection of pvy in the laboratory host nicotiana tabacum cv. petit havana sr1 and in various cultivars of the natural host solanum tuberosum by elisa as well as by western blots. the antibodies can be used for th ... | 2008 | 19085080 |
| virus diseases in the tobacco fields of guilan and western azerbaijan provinces of iran. | tobacco (nicotiana tabacum l.) is one of the important industrial plants in iran. viruses as an important group of plant pathogens cause many losses on the quality and quantity of tobacco crop. there was few information on the types of plant viruses infecting the tobacco fields of guilan and almost no information for western azerbaijan province. during 2005-2007, leaf samples were taken from symptomatic plants in the growing areas of these two provinces. the observed symptoms on plants in the fi ... | 2008 | 19226768 |
| identification and sequence analysis of potyviruses infecting crops in vietnam. | fifty-two virus isolates from 13 distinct potyvirus species infecting crops in vietnam were identified and the 3' region of each genome was sequenced. the viruses were: bean common mosaic virus (bcmv), potato virus y (pvy), sugarcane mosaic virus (scmv), sorghum mosaic virus (srmv), chilli veinal mottle virus (chivmv), zucchini yellow mosaic virus (zymv), leek yellow stripe virus (lymv), shallot yellow stripe virus (sysv), onion yellow dwarf virus (oydv), turnip mosaic virus (tumv), dasheen mosa ... | 2008 | 17906829 |
| antiphytoviral activity of bruceine-d from brucea javanica seeds. | brucea javanica (l.) merr. is widely distributed throughout the southern parts of china and has been used in traditional medicine to treat a variety of diseases. the objective of the present study was to identify the active antiphytoviral compound in the seeds of b. javanica and evaluate the inhibitory activity of the compound against plant virus. | 2008 | 17912689 |
| discussion paper: the naming of potato virus y strains infecting potato. | potato virus y (pvy) strain groups are based on host response and resistance gene interactions. the strain groups pvy(o), pvy(c) and pvy(n) are well established for the isolates infecting potato in the field. a switch in the emphasis from host response to nucleotide sequence differences in the virus genomes, detection of isolates recombining sequences of different strains, and the need to recognize isolates that cause necrotic symptoms in potato tubers have led to the assignment of new acronyms, ... | 2008 | 17943395 |
| a multiple single nucleotide polymorphisms interrogation assay for reliable potato virus y group and variant characterization. | the complex potato virus y classification, including groups (pvyn and pvyo) and variants (pvyntn and pvyn-w), is based mainly on biological properties of isolates. published pvy detection tools targeting markers not associated with biological properties could fail to assign correctly isolates in the current classification. to improve pvy detection tools, a single nucleotide polymorphism (snapshot) detection assay was developed. the technique was adapted to target the t/c9259, a/c2271, g/c8573 an ... | 2008 | 17931711 |
| virulence factor of potato virus y, genome-attached terminal protein vpg, is a highly disordered protein. | potato virus y (pvy) is a common potyvirus of agricultural importance, belonging to the picornavirus superfamily of rna plus-stranded viruses. a covalently linked virus-encoded protein vpg required for virus infectivity is situated at the 5' end of potyvirus rna. vpg seems to be involved in multiple interactions, both with other viral products and host proteins. vpgs of potyviruses have no known homologs, and there is no atomic structure available. to understand the molecular basis of vpg multif ... | 2008 | 17971447 |
| the novel gene ny-1 on potato chromosome ix confers hypersensitive resistance to potato virus y and is an alternative to ry genes in potato breeding for pvy resistance. | hypersensitive resistance (hr) is an efficient defense strategy in plants that restricts pathogen growth and can be activated during host as well as non-host interactions. hr involves programmed cell death and manifests itself in tissue collapse at the site of pathogen attack. a novel hypersensitivity gene, ny-1, for resistance to potato virus y (pvy) was revealed in potato cultivar rywal. this is the first gene that confers hr in potato plants both to common and necrotic strains of pvy. the loc ... | 2008 | 17985110 |
| genetic structure of a population of potato virus y inducing potato tuber necrotic ringspot disease in japan; comparison with north american and european populations. | the structure of potato virus y (pvy) populations causing potato tuber necrotic ringspot disease (ptnrd) was analysed. the full-length sequences of the genomic rnas of five geographically distinct isolates from japan were determined. recombination and phylogenetic analyses of european, north american and japanese isolates of pvy showed that the world pvy population has three major lineages and two sublineages. most recombinants were interlineage, and one isolate from europe was identified as an ... | 2008 | 18029044 |
| [complex formation between recombinant protein vpg of potato virus y and heterologous eukaryotic translation initiation factors eif4e]. | genomes of some positive-strand rna viruses do not contain cap-structure, but instead their 5'-end is covalently linked to a viral protein called vpg. complex formation between vpg and cellular translation initiation factors (eifs) has been extensively studied in the context of the model of this complex involvement in virus mrna translation initiation and cellular protein translation shut down in infected cells. the potato virus (pvy) vpg was expressed in bacterial and baculovirus systems in ord ... | 2007 | 18030737 |
| the hc-pro protein of potato virus y interacts with ntmind of tobacco. | potato virus y (pvy) infections often lead to altered numbers of host plant chloroplasts, as well as changes in morphology and inhibited photosynthesis. the multifunctional protein helper component-proteinase, hc-pro, has been identified in pvy-infected leaf chloroplasts. we used yeast two-hybrid and bimolecular fluorescence complementation assays to demonstrate that hc-pro can interact with the chloroplast division-related factor ntmind in yeast and tobacco cells, respectively. in addition, we ... | 2007 | 17990958 |
| no recombination detected in artificial potyvirus mixed infections and between potyvirus derived transgenes and heterologous challenging potyviruses. | risk-assessment studies of virus-resistant transgenic plants (vrtps) focussing on recombination of a plant virus with a transgenic sequence of a different virus should include a comparison of recombination frequencies between viruses in double-infected non-transgenic plants with those observed in singly infected transgenic plants to estimate recombination incidence in vrtps. in this study, the occurrence of recombination events was investigated in non-transgenic plants double-infected with two d ... | 2007 | 18001687 |
| natural infection of alternanthera tenella (amaranthaceae) by a new potyvirus. | a virus was isolated from joyweed (alternanthera tenella colla-amaranthaceae), a common weed in tropical and sub-tropical regions. examination by electron microscopy showed long flexuous particles with an average length of 756 nm in crude sap. serological results showed positive reaction with antisera to pvy-o. a fragment of 1772 nucleotides was sequenced. the cp sequence shares 76% of identity with the cp of potato virus y strain ntn. these results confirm that the virus is a new potyvirus infe ... | 2007 | 17668273 |
| the role of the coat protein region in symptom formation on physalis floridana varies between pvy strains. | the potato virus y (pvy) cdna full-length clone created by jakab et al. [jakab, g., droz, e., brigneti, g., baulcombe, d., malnoë, p., 1997. infectious in vivo and in vitro transcripts from a full-length cdna clone of pvy-n605, a swiss necrotic isolate of potato virus y. j. gen. virol. 78, 3141-3145] was stabilized by inserting three introns into putatively toxic genes. using this clone, hybrid viruses were constructed by in vitro recombination. the pvy-n/ntn and pvy-n/o chimeras carried the 3' ... | 2007 | 17482305 |
| a point mutation changes the serotype of a potato virus y isolate; genomic determination of the serotype of pvy strains. | a syrian isolate of potato virus y (pvy), named pvy-12, reacted to two monoclonal antibodies that are specific to pvy(o,c) and pvy(n) strains, although its coat protein (cp) belongs to the pvy(n) strain. analysis of the cp of pvy-12 revealed that a point mutation in its n terminus switched it from pvy(n)-like to pvy(o)-like at this position. this mutation changed the second nucleotide of the codon that encodes the 29th amino acid of the cp of pvy-12 from a to g, which resulted in one amino acid ... | 2007 | 17564823 |
| effect of mixed viral infections (potato virus y-potato leafroll virus) on biology and preference of vectors myzus persicae and macrosiphum euphorbiae (hemiptera: aphididae). | mixed viral infections of heterologous viruses such as potato virus y (family potyviridae, genus potyvirus, pvy) and potato leafroll virus (family luteoviridae, genus polerovirus, plrv) are a regular occurrence in idaho's potato, solanum tuberosum (l.), cropping systems. an increased number of plant samples from idaho's potato fields over the past 2 yr has serologically tested positive for both pvy and plrv via double antibody sandwich enzyme-linked immunosorbent assay (das-elisa) and exhibited ... | 2007 | 17598521 |
| enhanced resistance and neutralization of defense responses by suppressors of rna silencing. | the effects of transgenic expression of the potato virus y (pvy) hcpro silencing suppressor in tobacco were examined on infection by several viruses. infection by tobacco mosaic virus (tmv) was reduced at 25 degrees c, but not at 33 degrees c. by contrast, systemic infection at 33 degrees c by the tmv expressing green fluorescent protein was promoted by the hcpro. infection by tobacco rattle virus (trv) was restricted to local necrotic lesions by the pvy hcpro. however, this resistance was neutr ... | 2007 | 17617488 |
| the activity and isoforms of nadp-malic enzyme in nicotiana benthamiana plants under biotic stress. | the activity and presence of isoforms of nadp-dependent malic enzyme (nadp-me, ec 1.1.1.40) were studied in non-transgenic and transgenic nicotiana benthamiana plants containing potyviral gene for helper component protease (hc-pro) and in plants infected by potato virus y strain ntn (pvy(ntn)). no significant changes in enzyme activities and isoenzyme pattern were observed due to foreign gene introduction and pvy(ntn) infection. however, the activity and isoenzyme composition of nadp-me measured ... | 2007 | 18281746 |
| rapid identification of potato virus y strains by one-step triplex rt-pcr. | a one-step triplex rt-pcr method was characterised that allows rapid, strain-specific detection of potato virus y (pvy) occurring on potato: pvy(n), pvy(o), pvy(ntn) (recombinant isolates), pvy(n)wi and pvy(c). three specific primer pairs were designed on aligned pvy sequences available from genomic data banks. the specificity of the selected primers was first examined by simplex rt-pcr with a large number of pvy reference isolates. two fragments of 0.44 and 1.11kb were amplified for pvy(n) and ... | 2007 | 17157929 |
| molecular dissection of the potato virus y vpg virulence factor reveals complex adaptations to the pvr2 resistance allelic series in pepper. | the virulence properties of potato virus y (pvy) towards an allelic series at the pvr2 locus in pepper genotypes are related to variations in the genome-linked viral protein (vpg). eleven amino acid substitutions in the central part of the vpg were identified in strains differing by their virulence properties and were introduced, either singly or in combination, in an infectious pvy clone to get an in-depth genetic analysis of the virulence determinant. the virulence spectrum of these mutants wa ... | 2007 | 17412992 |
| capsid protein-mediated recruitment of host dnaj-like proteins is required for potato virus y infection in tobacco plants. | the capsid protein (cp) of potyviruses is required for various steps during plant infection, such as virion assembly, cell-to-cell movement, and long-distance transport. this suggests a series of compatible interactions with putative host factors which, however, are largely unknown. by using the yeast two-hybrid system the cp from potato virus y (pvy) was found to interact with a novel subset of dnaj-like proteins from tobacco, designated ntcpips. mutational analysis identified the cp core regio ... | 2007 | 17715215 |
| hc-pro protein of potato virus y can interact with three arabidopsis 20s proteasome subunits in planta. | the multifunctional protein helper component proteinase (hc-pro) is thought to interfere with the activity of the 20s proteasome; however, no sites of interaction have been identified for either protein. here, we first show that the potato virus y (pvy) hc-pro protein can interact with three arabidopsis 20s proteasome subunits (paa, pbb, and pbe), using a yeast two-hybrid system and the bimolecular fluorescence complement assay. in addition, yeast two-hybrid analysis of the interaction between s ... | 2007 | 17898064 |
| differentiation of potato virus y strains using improved sets of diagnostic pcr-primers. | potato virus y (pvy) is one of the most important viruses of potato world-wide, several strain groups are recognized. in the past two decades, novel pvy variants have appeared causing necrotic symptoms on potato tubers. implicated are two groups of recombinant strains: pvy(n)w and pvy(ntn), and na-pvy(ntn). while the first two are recombinants between pvy-n- and o-strains the latter is a recombinant between an n-strain and an unknown pvy strain or other potyvirus. available biological and molecu ... | 2007 | 17182113 |
| simultaneous detection of potato viruses, plrv, pva, pvx and pvy from dormant potato tubers by taqman real-time rt-pcr. | the requirements of sprouting dormant potato tubers for biological or serological assays or rna extraction for nucleic acid and pcr assays add to the cost of virus screening. recently, cheaper, reliable and more rapid methods for the screening of potato tuber-seed pieces for viruses have been developed that do not require sprouted tubers for indexing, including taqman real-time rt-pcr. although the assays are often designed for minimal time and reagent use, they still require a time-consuming an ... | 2007 | 17276522 |
| characterization of the expression and inheritance of potato leafroll virus (plrv) and potato virus y (pvy) resistance in three generations of germplasm derived from solanum etuberosum. | potato virus y (pvy) and potato leafroll virus (plrv) are two of the most important viral pathogens of potato. infection of potato by these viruses results in losses of yield and quality in commercial production and in the rejection of seed in certification programs. host plant resistance to these two viruses was identified in the backcross progeny of a solanum etuberosum lindl. somatic hybrid. multiple years of field evaluations with high-virus inoculum and aphid populations have shown the pvy ... | 2007 | 17318495 |
| stability of recombinant plant viruses containing genes of unrelated plant viruses. | the stability of hybrid plant viruses that might arise by recombination in transgenic plants was examined using hybrid viruses derived from the viral expression vectors potato virus x (pvx) and tobacco rattle virus (trv). the potato virus y (pvy) nib and hcpro open reading frames (orfs) were introduced into pvx to generate pvx-nib and pvx-hcpro, while the pvy nib orf was introduced into a vector derived from trv rna2 to generate trv-nib. all three viruses were unstable and most of the progeny vi ... | 2007 | 17374781 |
| engineering resistance to pvy in different potato cultivars in a marker-free transformation system using a 'shooter mutant' a. tumefaciens. | in this work, potato virus y (pvy) resistant potatoes were generated using an environmentally safe construct. for this purpose, a 'shooter' mutant agrobacterium-based transformation system was used. the isopentenyl transferase gene (ipt) present on the ti plasmid of 'shooter' strains enhances shoot regeneration and can be used as a phenotypic selection marker. the introduced marker-free binary vector carried a hairpin construct derived from the coat protein gene of pvy-ntn strain in order to ind ... | 2007 | 17103215 |
| estimation of the number of virus particles transmitted by an insect vector. | plant viruses are submitted to narrow population bottlenecks both during infection of their hosts and during horizontal transmission between host individuals. the size of bottlenecks exerted on virus populations during plant invasion has been estimated in a few pathosystems but is not addressed yet for horizontal transmission. using competition for aphid transmission between two potato virus y variants, one of them being noninfectious but equally transmissible, we obtained estimates of the size ... | 2007 | 17971440 |
| highly sensitive fluorescent-labeled probes and glass slide hybridization for the detection of plant rna viruses and a viroid. | in this study, a modified method of the conventional rna dot-blot hybridization was established, by replacing (32)p labels with cy5 labels and replacing nylon membranes with positive-charged glass slides, for detecting plant rna viruses and a viroid. the modified rna dot-blot hybridization method was named glass slide hybridization. the optimum efficiency of rna binding onto the surfaces of activated glass slide was achieved using aminosilane-coated glass slide as a solid matrix and 5xsaline sod ... | 2007 | 17492129 |
| macroarray detection of plant rna viruses using randomly primed and amplified complementary dnas from infected plants. | abstract membrane-based macroarrays provide a relatively inexpensive technology with the potential to detect hundreds of pathogens in a single assay. for the simultaneous detection of a large number of pathogens, it is necessary to obtain sufficient nucleic acids for labeling, and any amplification reactions need to be performed using unbiased, pathogen-non-specific primers. a nonradioactive macroarray system is described to test for plant rna viruses using 70-mer oligonucleotide probes immobili ... | 2007 | 18942945 |
| coat protein gene sequence analysis of potato virus x and potato virus y: conserved regions to design gene silencing cassette. | potato virus x(pvx) and potato virus y(pvy) are two of the three most prevalent viruses that cause significant yield declines in potato. twenty-seven pvx and thirty-seven pvy accessions were analyzed for nucleotide sequence variation of the coat protein gene. the average and variance of genetic distance for pvx were estimated at 0.118 and 0.004 and 0.118 and 0.005 for pvy using the neighbour joining method. results of phylogenetic trees and their certification via stepwise discriminant analysis ... | 2007 | 19102033 |
| salicylic acid suppresses potato virus y isolate n:o-induced symptoms in tobacco plants. | abstract the effects of salicylic acid (sa) and 1-aminocyclopropane-1-carboxylic acid (acc) on the systemic development of symptoms induced by a severe isolate of potato virus y group n:o (pvy(n:o)) in tobacco were investigated. upon inoculation, the systemic development of symptoms in tobacco plants could be divided into three stages: virus incubation stage, rapid symptom-progress stage, and partial recovery and symptom-shifting stage. treatment of seedlings with sa delayed the virus-induced ne ... | 2006 | 18944440 |
| evaluating the efficiency of a tpia method for the detection of two tobacco viruses. | field experiments are usually necessary for analyzing the efficiency of control methods, the resistance of varieties and many other virological studies. such experiments generally include a large number of samples to be tested serologically. das-elisa is a very accurate technique that has been widely used for identifying viral infections. for large numbers of plant samples, it takes a long time for the sample preparation, plate washing and other procedures. in this study, the efficiency of a sim ... | 2006 | 17390882 |
| [incidence and altitudinal distribution of 13 virus cultures in solanum tuberosum (solanaceae) from costa rica]. | a survey was conducted in 30 fields located at three different altitudes in cartago, costa rica's main potato producing area. twenty plants were sampled per farm, for a total of 600 samples with 200 samples per altitude. elisa was used with commercial reagents to independently test for pvx, pvy, pvm, pva, pvs, plrv, pmtv, pamv, pvv, pvt, aplv, apmov and trsv. the presence of the following viruses was determined: pvx (77 %), pamv (62 %), plrv (42 %), trsv (42 %), pvt (39 %), pvv (37 %), pmtv (31% ... | 2006 | 18457151 |
| potato virus y cfh, a putative recombinant isolate from capsicum chinense cv. habanero. | ornamental plants of chili pepper, capsicum chinense cv. habanero, with symptoms of leaf mosaic, necrotic rings on fruits and necrotic stems were observed in june 2003 in a private garden in the province of naples (italy). preliminary serological characterisation allowed the association of these symptoms with infections by potato virus y (pvy). the virus was isolated on nicotiana tabacum cv. xanthi and characterised by mechanical inoculation on herbaceous hosts and molecular characterisation of ... | 2006 | 17390887 |
| potato virus yisolated from pepper fields in tehran province. | potato virus y was known as the main cause of yellowing and vein necrosis of pepper in tehran province, using double antibody sandwich elisa (das-elisa). biological properties including host range of the isolate was determined after biological purification. host range studies showed that pepper isolate of pvy caused vein clearing and mosaic symptoms on datura metel and capsicum annum, mosaic on nicotiana tabacum cv. white barley, n. tabacum cv. samsun and n. rustica but didn't show any symptoms ... | 2006 | 17390898 |
| a bipartite system for the constitutive and inducible expression of high levels of foreign proteins in plants. | we have developed combined transgene/virus vector systems for the expression of heterologous proteins in plants. the systems are based on the bipartite rna plant virus, cowpea mosaic virus (cpmv), and involve the amplification of integrated copies of either full-length or deleted versions of rna-2 carrying a foreign gene. in the case of plants transgenic for full-length versions of rna-2 carrying the green fluorescent protein (gfp), amplification can be achieved by supplying rna-1 either exogeno ... | 2006 | 17177795 |
| high incidence of tobacco streak virus in the tobacco fields of iran. | currently the northern provinces of iran (mazandaran, golestan and gilan) are the main tobacco growing regions in the country and this crop has an special importance in the national economy. three tobacco types including flue-cured (mainly coker 347 and some virginia e1), burley (burley 21) and oriental (basma 178-2) are presently grown in these regions. epidemics of viral diseases have occurred during the recent years in many tobacco fields in these areas. the quality of tobacco products which ... | 2006 | 17390881 |
| whole genome characterization of potato virus y isolates collected in the western usa and their comparison to isolates from europe and canada. | potato virus y (pvy) is a serious potato pathogen that affects potato seed and commercial production crops. in recent decades, novel pvy strains have been described that cause necrotic symptoms on tobacco foliage and/or potato tubers. the major pvy strains that affect potato include pvy(o) and pvy(n), which have distinct serotypes that can be differentiated by immunoassay. other economically important strain variants are derived from recombination events, including variants that cause tuber necr ... | 2006 | 16463126 |
| the complete genome sequence of pepper severe mosaic virus and comparison with other potyviruses. | the complete nucleotide sequence of pepper severe mosaic virus (pepsmv) was determined. the viral genome consisted of 9890 nucleotides, excluding a poly (a) tract at the 3' end of the genome. the pepsmv rna genome encoded a single polyprotein of 3085 amino acid residues, resulting in ten functionally distinct potyviral proteins. the lengths of the 5' nontranslated region (ntr) and the 3' ntr were 164 and 468 nucleotides, respectively. the genome organization of the virus was typical for members ... | 2006 | 16699829 |
| transfer of phloem-mobile substances from the host plants to the holoparasite cuscuta sp. | during the development of the haustorium, searching hyphae of the parasite and the host parenchyma cells are connected by plasmodesmata. using transgenic tobacco plants expressing a gfp-labelled movement protein of the tobacco mosaic virus, it was demonstrated that the interspecific plasmodesmata are open. the transfer of substances in the phloem from host to the parasite is not selective. after simultaneous application of (3)h-sucrose and (14)c-labelled phloem-mobile amino acids, phytohormones, ... | 2006 | 16467411 |
| use of oils combined with low doses of insecticide for the control of myzus persicae and pvy epidemics. | experiments were carried out in the laboratory to assess the insecticidal effect on myzus persicae sulzer of different oils applied alone or combined with imidacloprid or pirimicarb. the oils tested were a horticultural mineral oil, a refined rapeseed oil, a refined soya oil and a raw fish oil. when the oils were sprayed alone on pepper plants infested with m. persicae, mineral oil caused the highest mortality of aphids (over 80%). applied before aphid infestation of pepper leaves and in mixture ... | 2006 | 16470683 |
| different mutations in the genome-linked protein vpg of potato virus y confer virulence on the pvr2(3) resistance in pepper. | five different amino acid substitutions in the vpg of potato virus y were shown to be independently responsible for virulence toward pvr2(3) resistance gene of pepper. a consequence of these multiple mutations toward virulence involving single nucleotide substitutions is a particularly high frequency of resistance breaking (37% of inoculated plants from the first inoculation) and suggests a potentially low durability of pvr2(3) resistance. these five mutants were observed with significantly diff ... | 2006 | 16673943 |