| nucleotide sequence of potato virus y (n strain) genomic rna. | the complete nucleotide sequence of the genomic rna of the potyvirus potato virus y strain n (pvyn) was obtained from cloned cdnas. this sequence is 9704 nucleotides long and can encode a polyprotein of 3063 amino acids. the positions of the cleavage sites at the n terminus of the capsid and cytoplasmic inclusion proteins have been determined. other putative protein cleavage sites have been deduced by searching for consensus sequences and by analogy with the polyprotein of the tobacco vein mottl ... | 1989 | 2732709 |
| coat protein gene-mediated resistance to potato virus y in tobacco: examination of the resistance mechanisms--is the transgenic coat protein required for protection? | we transformed sr1 tobacco with a cdna fragment of the potato virus y strain n (pvyn) 605 genome which contained the 3' end of the nib polymerase gene, the coat protein (cp) coding sequence, and most of the viral 3' untranslated region. complete resistance to several pvy strains was obtained in plants of the r2 generation. the resistance to pvyn and pvyo strains was maintained when the plants were inoculated dually with the potato potyviruses v or a (pvv or pva). only partial resistance to pvyn ... | 1993 | 8324247 |
| transgenic resistance to pvy(o) associated with post-transcriptional silencing of p1 transgene is overcome by pvy(n) strains that carry highly homologous p1 sequences and recover transgene expression at infection. | resistance to potato virus y (pvy) has been obtained in our previous studies through expression of the pvy p1 gene in sense or antisense orientation in potato cv. pito. in the present study, the mechanism and strain specificity of the resistance were analyzed. several features including low steady-state p1 mrna expression in the resistant p1 plants indicated that resistance was based on post-transcriptional gene silencing (ptgs). resistance was specific to pvy(o) isolates, the pvy strain group f ... | 2000 | 10755299 |
| genomic variability in potato potyvirus y (pvy): evidence that pvy(n)w and pvy(ntn) variants are single to multiple recombinants between pvy(o) and pvy(n) isolates. | fourteen potato virus y (pvy) isolates representative of pvy(o), pvy(n), pvy(ntn) and pvy(n)w groups were characterised at genomic level. restriction fragment length polymorphism study (rflp) of each gene of these isolates and sequencing of the first 2700 nucleotides of two pvy(n)w isolates were performed. a mosaic structure was revealed in pvy(n)w and pvy(ntn) genomes, which showed either pvy(o) or pvy(n)-like sequences, depending on the particular gene. indeed, starting from the 5'-end, these ... | 2002 | 11890528 |
| probable geographical grouping of pvy(n) and pvy(ntn) based on sequence variation in p1 and 5'-utr of pvy genome and methods for differentiating north american pvy(ntn). | an increasing number of countries in recent years have reported the occurrence of potato tuber necrotic ringspot disease (ptnrd), caused by tobacco veinal necrosis strain of potato virus y (pvy(n)), belonging to the sub-group tuber necrosis (pvy(ntn)). methods for the differentiation of pvy(ntn), based on primer sequences often detect isolates of european (eu) type but not the north american (na) type. to resolve this problem, the nucleotide sequence of 5'-untranslated region (5'-utr) and the p1 ... | 2002 | 12008009 |
| evolution of north american pvy(ntn) strain tu 660 from local pvy(n) by mutation rather than recombination. | a north american (na) isolate of tobacco veinal necrotic strain of potato virus y (pvy(n)) (n-jg) and a na isolate of potato tuber necrotic strain of potato virus y (pvy(ntn) (tu 660) were tested for their phenotypes by inoculation to potato plants of three potato cultivars. upon inoculation with tu 660, tubers of the cultivars 'norchip' and 'ranger russet' developed potato tuber necrotic ringspot disease (ptnrd) but not the tubers of 'russet burbank'. n-jg failed to induce ptnrd in the tested c ... | 2003 | 12680692 |
| pathogen-derived resistance in potato to potato virus y-aspects of stability and biosafety under field conditions. | plants of three different potato cultivars/lines were transformed via agrobacterium tumefaciens with a truncated nib gene of a necrotic strain of potato virus y (pvy(n)) which had been c-terminally fused to enhanced blue-fluorescing protein. resistance of the resulting transgenic clones was evaluated under glass house conditions using an ntn-strain of pvy. four clones with the highest levels of resistance were chosen for further experiments. their type of resistance was either recovery or extrem ... | 2004 | 15036834 |
| experimental and natural weed host-virus relations. | weeds, as alternative hosts of plant viruses and nutrient plants of virus vectors play important role in virus ecology and epidemiology. the aim of our study was to discover new weed-virus relations. therefore some weed species were mechanically inoculated with 28 viruses (strains or isolates) maintained in our glasshouse. different weed species with and without visible symptoms were collected from agro-, water ecosystems and wastelands of hungary between 1997 and 2003. virus infections were eva ... | 2004 | 15759395 |
| nutritional properties of tubers of conventionally bred and transgenic lines of potato resistant to necrotic strain of potato virus y (pvyn). | the potential effect of genetic modification on nutritional properties of potatoes transformed to improve resistance to a necrotic strain of potato virus y was determined in a rat experiment. autoclaved tubers from four transgenic lines were included to a diet in the amount of 40% and compared with the conventional cv. irga. the experiment lasted 3 weeks and special attention was paid to nutritional properties of diets, caecal metabolism and serum indices. genetic modification of potato had no n ... | 2005 | 16175247 |
| 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 |
| identification of pvy-n on potato and tobacco in tehran and mazandaran provinces. | during two growing seasons in years of 2003 and 2004 potato and tobacco of virus infected plants were collected from fields in tehran (damavand) and mazandaran (behshahr) provinces. serological methods of tas-elisa and diba were performed by using pvy antiserum (dsmz - plant virus collection; germany) but only pvy was detected. the strain of samples was determined by using mab of potato virus y (as-0403/1; dsmz; germany). the molecular weight of the virus coat protein was approximately 34 kda in ... | 2005 | 16637208 |
| improvement of potato virus y (pvy) detection and quantitation using pvy(n)- and pvy(o)-specific real-time rt-pcr assays. | a potato virus y (pvy) single nucleotide polymorphism (a/g(2213)), recently identified as a molecular determinant of the tobacco leaf necrosis symptom induced by pvy(n) isolates, has been used as a target to develop two pvy group-specific (pvy(n) and pvy(o)) fluorescent (taqman-based) real-time rt-pcr assays. these procedures allow detection, characterisation, and quantitation of a wide range of pvy isolates in samples containing 10(3)-10(8) viral transcripts. moreover, the high specificity of t ... | 2006 | 16513184 |
| 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 |
| 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 |
| 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 |
| characterization of potato virus y (pvy) molecular determinants involved in the vein necrosis symptom induced by pvyn isolates in infected nicotiana tabacum cv. xanthi. | viral molecular determinant(s) involved in the tobacco vein necrosis (tvn) symptom induced by necrotic isolates of potato virus y (pvy) on nicotiana tabacum cv. xanthi leaves remain undetermined. reference isolates belonging to pvy(n) (infectious pvy(n)-605 clone) and pvy(o) (pvy(o)-139) were used to produce pvy chimeric genomes by using reverse-genetic techniques. these chimeric clones were inoculated biolistically onto nicotiana clevelandii plants to establish the clone, prior to being tested ... | 2005 | 15958688 |
| specific detection of the pvy(n)-w variant of potato virus y. | pvy(n)-w is one of the variant populations of potato virus y (pvy). this variant is of concern in seed potato production and requires a specific diagnosis since it induces more or less symptomless infections and is not detectable easily in field inspections. moreover, this variant is serologically indistinguishable from the common strain pvy(o). this study describes a simple and specific molecular detection test for the pvy(n)-w variant using a pcr protocol based on the recombinant point within ... | 2005 | 15794982 |
| a single nucleotide polymorphism-based technique for specific characterization of yo and yn isolates of potato virus y (pvy). | one of the most important properties used to classify potato virus y (pvy) isolates is their ability to induce (pvy(n)) or not (pvy(o)) veinal necrosis symptoms on the indicator host plant nicotiana tabacum cv. xanthi. as an alternative to biological assays, several serological and molecular detection tools have been developed for pvy detection and characterization and these have evolved as our knowledge of pvy has improved. however, the assays that have been previously published are all based o ... | 2005 | 15737420 |
| characterisation of potato virus y nnp strain inducing veinal necrosis in pepper: a naturally occurring recombinant strain of pvy. | the full-length genome of potato virus y (pvy) nnp strain, recovered from pepper showing veinal necrosis of leaves, was cloned and sequenced, finding an organisation typical for pvy species. it consists of 9699 nucleotides (nt) excluding the 3' terminal poly(a) tail and contains an open reading frame of 9186 nt, encoding the putative polyprotein of 3061 amino acids. in elisa, the isolate reacted with a monoclonal antibody specific for pvy(c) but not with antibodies against pvy(n) or pvy(o). sequ ... | 2004 | 15592887 |
| 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 |
| influence of cooking and microwave heating on microstructure and mechanical properties of transgenic potatoes. | the transgenic potato clones of cultivar irga with improved resistance to a necrotic strain of potato virus y (pvy(n)) were subjected to heat treatment in order to determine their technological quality. the technological quality was determined on the basis of differences between mechanical properties of unmodified potato and transgenic clones during cooking and microwave heating. the compression test was applied in order to evaluate the mechanical resistance of raw, cooked and microwave-treated ... | 2004 | 15285106 |
| [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 |
| specific differentiation of recombinant pvy(n:o) and pvy(ntn) isolates by multiplex rt-pcr. | the recombinant isolates of tobacco veinal necrotic strain of potato virus y (pvyn) and potato tuber necrotic group (pvy(ntn)) contain segments of the pvyo and the pvy(n) genome. three major recombinant junctions (rj) are present in the genome of the recombinant pvy(ntn) at sites hc/pro-p3, 6k2-nia, and the c-terminal region of cp gene and one rj at hc/pro-p3 site in some recombinant pvyn isolates (termed pvy(n:o)). protocols for specific differentiation of the recombinant pvy(ntn) and pvy(n:o) ... | 2003 | 14553892 |
| the complete nucleotide sequence of pepper mottle virus-florida rna. | the pepper mottle virus-florida (pepmov-fl) rna genome was cloned and sequenced, and shown to consist of 9,717 nucleotides (nt) excluding the poly (a) tail. a single open reading frame was identified beginning at nucleotide position 169 encoding a polyprotein of 3068 amino acids. phylogenetic sequence analysis revealed that of 44 full-length viral rna genomes analyzed within the family potyviridae, pepmov-fl was most closely related to pepmov-california (pepmov-ca), potato virus y-h (pvy-h), pvy ... | 2003 | 12536304 |
| immunocapture rt-pcr probing of potato virus y isolates. | twenty potato virus y (pvy) isolates were characterized. they represented two strains only, pvy(o) (three isolates) and pvy(n) (17 isolates). however, application of serological and molecular genetic methods led to a more complicated characterization. for example, five isolates induced necrotic symptoms on tobacco plants typical of pvy(n), despite reacting as pvy(o) serologically. moreover, the pvy isolates were not identical according to molecular genetic properties. typical pvy(ntn) pcr produc ... | 2002 | 12387496 |
| a new approach for the simultaneous differentiation of biological and geographical strains of potato virus y by uniplex and multiplex rt-pcr. | two strains of potato virus y (pvy), the common (pvy(o)) and the tobacco veinal necrosis (pvy(n)) have been known for decades. more recently, a tuber ringspot necrosis (pvy(ntn)), and several recombinants of pvy(o) and pvy(n) (designated here as pvy(n:o)) have been described. further, the pvy(n) group of strains have been assigned to two geographical subgroups of european (eu) pvy(n/ntn) and the north american (na) pvy(n/ntn). the evolution of new pvy(n) strains, has complicated the diagnosis, w ... | 2002 | 12020791 |
| the detection of tuber necrotic isolates of potato virus y, and the accurate discrimination of pvy(o), pvy(n) and pvy(c) strains using rt-pcr. | potato tuber necrotic ringspot disease (ptnrd) is a damaging disease of potatoes, causing unsightly necrotic rings on the surface of tubers. the causal agent is thought to be tuber necrotic isolates of potato virus y, known as pvy(ntn). the disease spoils tubers for processing and table use, and the lack of a diagnostic method makes control especially difficult. the development of an rt-pcr assay for the reliable detection of pvy(ntn) and discrimination of all the main strains of pvy (pvy(o), pv ... | 2002 | 11879698 |
| evidence for expression level-dependent modulation of carbohydrate status and viral resistance by the potato leafroll virus movement protein in transgenic tobacco plants. | high-level constitutive expression of the cell-to-cell movement protein from the phloem-restricted potato leafroll virus (plrv-mp17) in transgenic tobacco plants leads to growth retardation and severe phenotypic changes of source leaves paralleled by a drastic accumulation of soluble sugars and starch (herbers et al., 1997). to investigate whether the mp17-induced alteration in carbon metabolism is related to the targeting and modification of specific plasmodesmata (pd) or is rather due to pleio ... | 2001 | 11849593 |
| development of a multiplex amplidet rna assay for simultaneous detection and typing of potato virus y isolates. | a multiplex amplidet rna assay was developed for the specific detection of potato virus y (pvy), and for the differentiation of the pvy(n), pvy(o/c) strains and the tuber necrotic isolates (pvy(ntn)). the assay is based on the generic amplification of a region within the coat protein coding region of all known pvy isolates by nucleic acid sequence-based amplification (nasba) and strain-specific detection by molecular beacons. pvy(ntn)-specific diagnosis is achieved by detecting pvy(n) and pvy(o) ... | 2002 | 11742655 |
| differentiating pvy(ntn) from pvy(n) by annealing to reference rna transcripts. | a method for the differentiation of virus strains based on the shift in electrophoretic mobility of partially annealed rna transcripts is described. oppositely oriented rna transcripts of the ntn- and n-strains of pvy, complementary at their 3'-end variable (strain-specific) region, were annealed to form a partial duplex which moved more slowly in gel than heterologous (ntn+n) unpaired transcripts. thus, the two virus strains could be identified by annealing to a known reference transcript. the ... | 2001 | 11483223 |
| 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 |
| detection of different strains of potato virus y and their mixed infections using competitive fluorescent rt-pcr. | a competitive fluorescent rt-pcr assay (cf rt-pcr) was developed for the rapid and reliable detection and discrimination of the two most common strains of potato virus y (pvy) found in potato (necrotic and ordinary). the assay incorporates two strain specific primers labelled with fluorescent labels, used in conjunction with a universal pvy primer. the strain specific primers compete for the same annealing site which further increases specificity. discrimination is conferred by the fluorescent l ... | 2001 | 11164498 |
| 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 |
| some epidemiological approaches to the control of aphid-borne virus diseases in seed potato crops in northern europe. | an account is given of progress during the last 30 years in knowledge of the epidemiology of diseases caused by aphid-borne viruses in seed potato production areas of northern europe. during this period, potato leafroll virus (plrv) and strains of potato virus y (pvy(o), pvy(n)) were consistently the most prevalent and harmful. the main factors influencing spread involve the amount of initial virus inoculum in seed crops, agricultural practices in relation to seed potato production, the status o ... | 2000 | 11137160 |
| strain specific recombinant antibodies to potato virus y potyvirus. | single chain fv antibody fragments have been selected from a synthetic phage-antibody library following three and four rounds of affinity selection with purified potato virus y, common strain (pvy(o)). the selected fragments were highly specific for pvy and detected seven out of nine isolates of pvy(o) whilst failing to detect three isolates of pvy(n) and 12 isolates of pvy(ntn). nucleotide sequence of the scfv genes showed the variable heavy fragments belonged to the human vh4 family, whilst th ... | 1998 | 9779619 |
| separation of slovenian isolates of pvy(ntn) from the north american isolates of pvy(n) by a 3-primer pcr. | the potato tuber ringspot necrosis isolate of potato virus y (pvy(ntn)) is a recently recognized and highly aggressive isolate of the pvy(n) group of strains. in order to screen specifically sources of resistance to pvy(ntn) a method to separate pvy(ntn) from pvy(n) is needed. to achieve this, 61 isolates from 13 imported and locally developed potato cultivars in slovenia were studied. on the basis of the reactions in indicator plants nicotiana tabacum cv. samsun and solanum brachycarpum and wit ... | 1998 | 9628222 |
| expression of a luteoviral movement protein in transgenic plants leads to carbohydrate accumulation and reduced photosynthetic capacity in source leaves. | elucidating the role of viral genes in transgenic plants revealed that the movement protein (mp) from tobacco mosaic virus is responsible for altered carbohydrate allocation in tobacco and potato plants. to study whether this is a general feature of viral mps, the movement protein mp17 of potato leafroll virus (plrv), a phloem-restricted luteovirus, was constitutively expressed in tobacco plants. transgenic lines were strongly reduced in height and developed bleached and sometimes even necrotic ... | 1997 | 9418046 |
| [the antigenic characteristics of the capsid proteins in strains of the potato virus y]. | the antigenic properties of capsid proteins of potato virus y (pvy) strains have been studied, the most wide antigenic specificity of necrotic group strains has been marked. several antigen-active strains of necrotic group strains (pvy-n far east, pvy-n leningrad, pvy-n moscow) and common group (pvy-o-3 moscow, pvy-o far east) have been revealed. antisera against these strains reacted with any pvy strain. virus specific surface epitope, corresponding to position 198-208 of polypeptide chain has ... | 1991 | 1722712 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| diversity among potato virus y isolates obtained from potatoes grown in the united states. | abstract potato field isolates (solanum tuberosum) of potato virus y (pvy) collected from the midwestern and western united states were characterized using serological, molecular, and biological assays. pvy field isolates were grouped into the previously defined categories: pvy(o), european pvy(ntn), north american pvy(ntn), and pvy(n:o) recombinant and four previously undefined groups. studies reported here agree with published reports from europe and elsewhere in north america as pvy isolates ... | 2004 | 18943708 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| the potato virus y m(s)n(r) nib-replicase is the elicitor of a veinal necrosis-hypersensitive response in root knot nematode resistant tobacco. | summary a root knot nematode resistance gene in nicotiana tabacum, rk, providing resistance to the nematode parasite meloidogyne incognita is tightly linked to, or is a pleiotropic gene with a veinal necrosis systemic hypersensitive response to infection by potato virus y (pvy) m(s)n(r). the single pvy m(s)n(r) open reading frame was sequenced and found to have 89% protein identity to pvy n. individual pvy m(s)n(r) polypeptides were deduced and the corresponding cdna were cloned into a potato vi ... | 2002 | 20569320 |
| regulation of carbohydrate partitioning during the interaction of potato virus y with tobacco. | abstract to test whether carbohydrates may play a signalling function during plant pathogenesis, we investigated the interaction between tobacco and potato virus y (pvy(n)). four days after pvy(n) infection, leaves started to accumulate soluble sugars and leaf photosynthesis decreased. the accumulation of soluble sugars was accompanied by an induction of cell wall invertase and a gradual decrease in the sucrose-to-hexose ratio. in parallel to changes in carbohydrate metabolism and photosynthesis ... | 2000 | 20572950 |
| complementations and exclusions between mutated versions of a potato virus y genotype during mixed infections of nicotiana hosts. | understanding the processes that have led to the recent prevalence of necrotic genotypes in pvy populations is an important challenge for research programs studying this virus. non-necrotic pvy(o)-139, necrotic pvy(n)-605 and point mutated versions of pvy(n)-605 (pvy(kred), pvy(kr) and pvy(ed)), were used in mixtures to inoculate two nicotiana hosts which express (n. tabacum cv. xanthi) or not (n. clevelandii) necrosis symptoms in response to infection by pvy(n) group members. the comparison dur ... | 2010 | 20708049 |
| genetic diversity of potato virus y infecting tobacco crops in china. | genetic variability of potato virus y (pvy) isolates infecting potato has been characterized but little is known about genetic diversity of pvy isolates infecting tobacco crops. in this study, pvy isolates were collected from major tobacco-growing areas in china and single-lesion isolates were produced by serial inoculation on chenopodium amaranticolor. most isolates (88%) caused systemic veinal necrosis symptoms in tobacco. of these, 16 isolates contained a pvy(o)-like coat protein (cp) and pvy ... | 2011 | 20977310 |
| 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 |
| differential pathogenicity of two different recombinant pvyntn isolates in physalis floridana is likely determined by the coat protein gene. | abstract: a previous study has identified two types of recombinant variants of potato virus y strain ntn (pvyntn) in china and sequenced the complete genome of the variant pvyntn-hn2. in this study, the complete genome of isolate pvyntn-hn1 was fully sequenced and analyzed. the most striking difference between the two variants was the location of recombinant joint three (rj3). in pvyntn-hn1, like other typical european-pvyntn isolates such as pvyntn-hun, the rj3 was located at nucleotide (nt) 91 ... | 2011 | 21548970 |
| within plant distribution of potato virus y in hairy nightshade (solanum sarrachoides): an inoculum source affecting pvy aphid transmission. | potato virus y (pvy) is vectored by several potato-colonizing and non-colonizing aphid species in a non-persistent manner and has a wide host range. it occurs naturally in several plant families. myzus persicae and macrosiphum euphorbiae are the most efficient potato-colonizing aphid vectors of pvy. rhopalosiphum padi, a cereal aphid that migrates in large numbers through potato fields during the middle of the growing season, does not colonize potato plants but can transmit pvy. hairy nightshade ... | 2011 | 21601597 |
| identification of the molecular make-up of the potato virus y strain pvy(z): genetic typing of pvy(z)-ntn. | abstract potato virus y (pvy) strains were originally defined by interactions with different resistance genes in standard potato cultivars. five distinct strain groups are defined that cause local or systemic hypersensitive responses (hrs) in genetic background with a corresponding n gene: pvy(o), pvy(n), pvy(c), pvy(z), and pvy(e). the nucleotide sequences of multiple isolates of pvy(o) and pvy(n) differ from each other by ôëê8% along their genomes. additionally, complete genome sequences of mu ... | 2011 | 21834725 |
| Genetic diversity of the ordinary strain of Potato virus Y (PVY) and origin of recombinant PVY strains. | The ordinary strain of Potato virus Y (PVY), PVY(O), causes mild mosaic in tobacco and induces necrosis and severe stunting in potato cultivars carrying the Ny gene. A novel substrain of PVY(O) was recently reported, PVY(O)-O5, which is spreading in the United States and is distinguished from other PVY(O) isolates serologically (i.e., reacting to the otherwise PVY(N)-specific monoclonal antibody 1F5). To characterize this new PVY(O)-O5 subgroup and address possible reasons for its continued spre ... | 2011 | 21675922 |
| Enhanced sensitivity to higher ozone in a pathogen-resistant tobacco cultivar. | Investigations of the effects of elevated ozone (O(3)) on the virus-plant system were conducted to inform virus pathogen management strategies better. One susceptible cultivar of tobacco (Nicotiana tabacum L. cv. Yongding) and a resistant cultivar (Nicotiana tabacum L. cv. Vam) to Potato virus Y petiole necrosis strain (PVY(N)) infection were grown in open-top chambers under ambient and elevated O(3) concentrations. Above-ground biomass, foliage chlorophyll, nitrogen and total non-structural car ... | 2011 | 22090443 |