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1.
Arch Virol ; 164(11): 2849-2852, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31502078

RESUMO

Arracacha virus B type (AVB-T) and oca (AVB-O) strains from arracacha (Arracacia xanthorrhiza) and oca (Oxalis tuberosa) samples collected in 1975 and two additional isolates obtained from arracacha (AVB-PX) and potato (AVB-6A) in Peru in 1976 and 1978, respectively, were studied. In its host responses and serological properties, AVB-PX most resembled AVB-T, whereas AVB-6A most resembled AVB-O. Complete genomic sequences of the RNA-1 and RNA-2 of each isolate were obtained following high-throughput sequencing of RNA extracts from isolates preserved for 38 (AVB-PX) or 32 (the other 3 isolates) years, and compared with a genomic sequence of AVB-O obtained previously (PV-0082). RNA-2 was unexpectedly divergent compared to RNA-1, with the nucleotide (nt) sequence identity of different AVB isolates varying by up to 76% (RNA-2) and 89% (RNA-1). The coat protein amino acid sequences were the most divergent, with AVB-O and AVB-6A having only 68% identity to AVB-T and AVB-PX. Since the RNA2 sequence differences between the two isolate groupings also coincided with host range, symptom, and serological differences, AVB demonstrates considerable intraspecific divergence.


Assuntos
Genoma Viral/genética , RNA Viral/genética , Secoviridae/genética , Sequência de Aminoácidos , Sequência de Bases , Proteínas do Capsídeo/genética , Sequenciamento de Nucleotídeos em Larga Escala , Magnoliopsida/virologia , Oxalidaceae/virologia , Peru , Doenças das Plantas/virologia , Secoviridae/isolamento & purificação , Solanum tuberosum/virologia
2.
Arch Virol ; 164(11): 2891-2894, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31506787

RESUMO

Contigs with sequence similarity to potato virus P (PVP), which belongs to the genus Carlavirus, were identified by high-throughput sequencing analysis in potato tubers collected from a farmer's potato production field in Surazhevka, Artyom, Primorskiy Krai (Russia) in 2018. The complete genome sequence of this virus consisted of 8,394 nucleotides, excluding the poly(A) tail. This is the first report of PVP being detected outside South America. The isolate had high sequence similarity to PVP isolates from Argentina and Brazil, but low sequence similarity was observed in the genes encoding the RNA-dependent RNA polymerase (69% nucleotide sequence identity and 80% amino acid sequence identity) and coat protein (78% nucleotide sequence identity and 89% amino acid sequence identity). Phylogenetic analysis revealed that this PVP-like virus clustered with known PVP isolates but was distinct from them. Comparison of the sequences using the classification criteria of the ICTV indicated that this PVP-like virus is a strain of PVP.


Assuntos
Carlavirus/genética , Genoma Viral/genética , Doenças das Plantas/virologia , Solanum tuberosum/virologia , Sequência de Aminoácidos , Proteínas do Capsídeo/genética , Carlavirus/classificação , Carlavirus/isolamento & purificação , RNA Polimerases Dirigidas por DNA/genética , Sequenciamento de Nucleotídeos em Larga Escala , RNA Viral/genética , Federação Russa , Sequenciamento Completo do Genoma
3.
Plant Dis ; 103(11): 2933-2939, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31545136

RESUMO

A new virus with flexuous, filamentous particles approximately 650 nm long was discovered in Manchurian tubergourd (Thladiantha dubia Bunge) leaves exhibiting severe mosaic symptoms. The whole genome sequence of the virus was determined by reverse transcription-polymerase chain reaction (RT-PCR) and rapid amplification of cDNA ends (RACE). The entire genome consisted of 10,112 nucleotides (nt) excluding the poly (A) tail, which shared the highest nucleotide sequence identity (73.8%) with that of papaya leaf distortion mosaic virus Hainan-DF isolate (PLDMV-Hainan-DF). A phylogenetic analysis showed that this virus clustered with PLDMV isolates in a subbranch within the potyviral clade. Of the 23 species of indicator plants tested, only potato and its original host were systemically infected by the virus tested upon mechanical inoculation. A field survey showed that the virus was widely distributed on T. dubia and potatoes in Northeast China. Moreover, this virus displayed a high degree of genetic variation as evaluated by the sequences of the coat protein (CP) gene. Based on these results, the name Thladiantha dubia mosaic virus (ThDMV) is proposed for this new potyvirus.


Assuntos
Cucurbitaceae , Filogenia , Potyvirus , China , Cucurbitaceae/virologia , Genoma Viral/genética , Doenças das Plantas/virologia , Potyvirus/classificação , Potyvirus/genética , Potyvirus/fisiologia , Solanum tuberosum/virologia
4.
Plant Dis ; 103(9): 2221-2230, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31287755

RESUMO

Potato virus Y (PVY) exists as several strains with distinct symptomology and tuber yield effects in different potato varieties. Recently, new recombinant strains have proliferated and dominated local populations around the world. In this study, PVYO, PVYN:O, PVYN-Wi, and PVYNTN strains were tracked across Canada from 2014 to 2017, showing rapid evolution of populations away from the traditionally dominant PVYO to recombinants PVYN-Wi (western Canada) and PVYNTN (eastern Canada). Simultaneously, 30 potato varieties were inoculated with PVYO, PVYN:O, and PVYNTN in controlled greenhouse experiments. Foliar symptoms of primary (mechanical inoculation mimicking aphid infection) and secondary (tuber seedborne) infection were cataloged, and tuber yield measured. On average, and generally similar in primary and secondary infection, symptom expression and yield reduction were most severe with PVYO, followed by PVYN:O and PVYNTN. Strong mosaic symptoms were most commonly expressed with PVYO infection, and only seen with PVYN:O or PVYNTN in 15 and 3 varieties, respectively. Across variety-strain combinations, yield reduction was correlated with symptom severity, most strongly in PVYO-infected plants (e.g., AC Chaleur, Beljade, Envol, Norland, and Pacific Russet), and four varieties exhibited tuber necrotic ringspot disease with PVYNTN (AC Chaleur, Envol, Pacific Russet, and Yukon Gold).


Assuntos
Doenças das Plantas , Potyvirus , Vírus Reordenados , Solanum tuberosum , Replicação Viral , Animais , Cruzamento , Canadá , Doenças das Plantas/virologia , Potyvirus/genética , Potyvirus/fisiologia , Vírus Reordenados/fisiologia , Solanum tuberosum/virologia
5.
Plant Dis ; 103(9): 2179-2183, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31322494

RESUMO

Potato virus Y (PVY) is among the most economically impactful potato pathogens, yet the spread of PVY from infected seed potatoes within commercial potato fields has not been adequately studied. Test lots containing various seed-borne PVY levels were created by mixing different proportions of seed pieces from healthy and infected tubers drawn from the same seed source. These seed lots were planted in commercial potato fields near the Teton Seed Potato Management Area from 2010 to 2012. Regression analyses on data from these test plots produced models of the in-season spread of PVY originating from infected seed. Conventional ordinary least squares techniques were supplemented with the use of quantile regression; the resulting models indicate the significance of seed-borne PVY on end-of-season infection levels and highlight the need of seed potato buyers to review postharvest testing results.


Assuntos
Doenças das Plantas , Tubérculos , Potyvirus , Solanum tuberosum , Agricultura , Doenças das Plantas/prevenção & controle , Doenças das Plantas/virologia , Tubérculos/virologia , Solanum tuberosum/virologia
6.
Arch Virol ; 164(6): 1691-1695, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30968213

RESUMO

Potato virus Y (PVY) is the most common virus infecting potato worldwide. We analysed potato tuber PVY infections from the major Israeli growing region in 2014-2017. Isolates were characterized by multiplex PCR according to Chikh-Ali et al. (Plant Disease 97, 1370, 2013), whose primers were not fully compatible with the Israeli isolates. New primers were designed for a multiplex PCR assay to differentiate the Israeli isolates. Three recombinant strains were observed: PVYNTNa (72% of the isolates), PVYNWi (24%) and PVYSyr-III (found only in 2015). The archetypal PVYO strain was found only once. The classical PVY strains have recently been displaced by recombinant forms, with PVYNTNa dominating. The Israeli isolates appear very similar to those of Europe (the seed tuber source), except for PVYSyr-III.


Assuntos
Reação em Cadeia da Polimerase Multiplex/métodos , Potyvirus/isolamento & purificação , Solanum tuberosum/virologia , Primers do DNA/genética , Genoma Viral , Israel , Doenças das Plantas/virologia , Potyvirus/genética , Vírus Reordenados/genética , Vírus Reordenados/isolamento & purificação , Análise de Sequência de RNA
7.
Dokl Biochem Biophys ; 484(1): 88-91, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-31012023

RESUMO

The role of the nuclear protein coilin in the mechanisms of resistance of potato Solanum tuberosum cultivar Chicago to biotic and abiotic stresses was studied using the CRISPR-Cas9 technology. For the coilin gene editing, a complex consisting of the Cas9 endonuclease and a short guide RNA was immobilized on gold or chitosan microparticles and delivered into apical meristem cells by bioballistics or vacuum infiltration methods, respectively. Editing at least one allele of the coilin gene considerably increased the resistance of the edited lines to infection with the potato virus Y and their tolerance to salt and osmotic stress.


Assuntos
Resistência à Doença , Meristema , Proteínas Nucleares , Pressão Osmótica , Doenças das Plantas/virologia , Proteínas de Plantas , Rhabdoviridae/metabolismo , Solanum tuberosum , Sistemas CRISPR-Cas , Meristema/genética , Meristema/metabolismo , Meristema/virologia , Proteínas Nucleares/genética , Proteínas Nucleares/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Solanum tuberosum/genética , Solanum tuberosum/metabolismo , Solanum tuberosum/virologia
8.
Viruses ; 11(3)2019 03 12.
Artigo em Inglês | MEDLINE | ID: mdl-30871002

RESUMO

Since the early 1970s when "virus-like" agents were considered as the cause of two diseases (potato spindle tuber and citrus exocortis), their study and further characterization have been linked to the development and use of molecular biology tools. Sucrose density gradient centrifugation and polyacrylamide gel electrophoresis (PAGE) played a critical role in the pioneering studies of PSTVd and citrus exocortis viroid (CEVd). This was later modified by using other PAGEs (sequential PAGE, return PAGE, two-dimensional PAGE), and/or different staining methods (ethidium bromide, silver nitrate, etc.). Since then, disease-causing agents suspected to be viroids were usually subjected to a number of tests to define their: (i) Molecular nature (RNA or DNA; single stranded or double stranded; circular or linear RNA); (ii) molecular weight; (iii) secondary and tertiary structure. Further biological assays are also essential to establish the relationship of a viroid with plant disease and to fulfill Koch's postulates.


Assuntos
Doenças das Plantas/virologia , Viroides/isolamento & purificação , Viroides/patogenicidade , Citrus/virologia , Eletroforese em Gel de Poliacrilamida , História do Século XX , Doenças das Plantas/história , RNA Viral , Solanum tuberosum/virologia , Técnicas de Cultura de Tecidos , Viroides/genética , Virologia/métodos
9.
Viruses ; 11(2)2019 02 20.
Artigo em Inglês | MEDLINE | ID: mdl-30791535

RESUMO

Higher plants exploit posttranscriptional gene silencing as a defense mechanism against virus infection by the RNA degradation system. Plant RNA viruses suppress posttranscriptional gene silencing using their encoded proteins. Three important motifs (F-box-like motif, G139/W140/G141-like motif, and C-terminal conserved region) in P0 of Potato leafroll virus (PLRV) were reported to be essential for suppression of RNA silencing activity. In this study, Agrobacterium-mediated transient experiments were carried out to screen the available amino acid substitutions in the F-box-like motif and G139/W140/G141-like motif that abolished the RNA silencing suppression activity of P0, without disturbing the P1 amino acid sequence. Subsequently, four P0 defective mutants derived from a full-length cDNA clone of PLRV (L76F and W87R substitutions in the F-box-like motif, G139RRR substitution in the G139/W140/G141-like motif, and F220R substitution in the C-terminal conserved region) were successfully generated by reverse PCR and used to investigate the impact of these substitutions on PLRV infectivity. The RT-PCR and western blot analysis revealed that these defective mutants affected virus accumulation in inoculated leaves and systemic movement in Nicotiana benthamiana as well as in its natural hosts, potato and black nightshade. These results further demonstrate that the RNA silencing suppressor of PLRV is required for PLRV accumulation and systemic infection.


Assuntos
Inativação Gênica , Luteoviridae/genética , Mutação , Tabaco/virologia , Proteínas Virais/genética , Agrobacterium/genética , Substituição de Aminoácidos , Motivos F-Box/genética , Doenças das Plantas/virologia , Vírus de Plantas/genética , Solanum tuberosum/virologia
10.
Talanta ; 195: 739-744, 2019 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-30625610

RESUMO

This study presents new type of the lateral flow immunoassay (LFIA) for multi-target analysis. A test, named alarm-LFIA, has an essentially new function that consists in notice (signaling the danger) about the presence at least one target from the controlled list without identification. The design of the alarm-LFIA assumes one test zone, which contains a mixture of antibodies, and multi-specific conjugate that binds the several targets. The alarm test is based on the novel conjugate with broaden specificity due to the immobilisation of a mix of antibodies, specific to several structurally different targets, on the surface of gold nanoparticles. For proof of concept, multi-specific conjugate to five important potato viruses (potato virus X, -M, -S, -Y and potato leaf roll virus) was fabricated using five antibodies with different specificity. The alarm-LFIA was developed for rapid detection of the total infection caused by up to five viruses. Detection limits of the viruses in potato leaf extracts are from 10 to 30 ng/mL. The alarm-LFIA was successfully used for viruses' detection in potato leaves; results were confirmed by enzyme-linked immunosorbent assay. The proposed approach of alarm-LFIA shows great potential for the various cases when different targets of interest can occur simultaneously or separately in samples.


Assuntos
Extratos Vegetais/análise , Folhas de Planta/virologia , Vírus de Plantas/isolamento & purificação , Solanum tuberosum/virologia , Anticorpos Antivirais/química , Anticorpos Antivirais/imunologia , Ouro/química , Imunoensaio , Nanopartículas Metálicas/química , Vírus de Plantas/imunologia
11.
J Plant Physiol ; 232: 107-114, 2019 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-30537597

RESUMO

Although structurally simple, viroids can trigger numerous changes in host plants and cause loss of yield in agronomically important crops. This study investigated changes in the endogenous status of phytohormones and antioxidant enzyme activity in Solanum tuberosum cv. Désirée in response to Potato spindle tuber viroid (PSTVd) infection. Phytohormone analysis showed that the content of endogenous jasmonic acid (JA) and its precursor cis-OPDA significantly increased in leaves, while the content of castasterone (CS) increased in both leaves and tubers of systemically infected plants compared to mock-inoculated control plants at 8 weeks post-inoculation. The indole-3-acetic acid content moderately increased only in tubers, while no differences in salicylic acid and abscisic acid content were observed between infected and control plants. Changes in endogenous phytohormone content were associated with upregulated expression of genes involved in the biosynthesis of JA and brassinosteroids, and the metabolism of auxins. Additionally, PSTVd infection provoked overproduction of hydrogen peroxide, which coincided with increased activity of guaiacol peroxidase in leaves and ascorbate peroxidase in potato tubers. The activity of catalase decreased in leaves, while superoxide dismutase activity remained steady regardless of the treatment and organ type. Total ascorbate and glutathione did not change significantly, although a shift towards oxidized forms was observed. Results suggest the existence of organ-specific differences in phytohormone and antioxidative responses in potato upon PSTVd infection. Possible effects of the observed changes on symptom development are discussed.


Assuntos
Doenças das Plantas/virologia , Reguladores de Crescimento de Planta/metabolismo , Solanum tuberosum/fisiologia , Viroides/metabolismo , Antioxidantes/metabolismo , Brassinosteroides/metabolismo , Clorofila/metabolismo , Colestanóis/metabolismo , Ciclopentanos/metabolismo , Ácidos Indolacéticos/metabolismo , Oxilipinas/metabolismo , Folhas de Planta/metabolismo , Tubérculos/metabolismo , Solanum tuberosum/metabolismo , Solanum tuberosum/virologia
12.
Plant Dis ; 103(2): 192-199, 2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-30592697

RESUMO

Seed potato certification programs aim to limit disease incidence in planting material to levels below a threshold that causes significant losses to seed potato buyers. Records maintained for seed potato certification can be analyzed for trends in seed potato varietal mixture and disease incidences over time. We used logistic regression models to determine effects of year, potato variety, and their interaction on the incidences of potato diseases and disorders based on seed potato certification data collected in Colorado from 2012 to 2016. The effect of seed generation of important varieties on the incidence of common potato diseases was also quantified. Among the documented diseases, mosaic, caused primarily by Potato virus Y, is a persistent problem leading to high percentage of seed lot rejections in both summer and winter inspections, while blackleg, caused by Dickeya spp. and Pectobacterium spp., was a common disease causing summer rejections. The model demonstrated year, potato variety, and their interaction were key factors contributing to incidence of varietal mixture, or one or more potato diseases and disorders. For summer inspections, our models identified 53, 42, and six varieties sensitive to mosaic, blackleg, and leafroll, respectively. There were 17, 15, and six varieties that were tolerant to mosaic, blackleg, and leafroll regardless of pathogen pressures in the environment. For winter inspections, 51 varieties were sensitive to mosaic and three to leafroll, whereas 45 and one were relatively tolerant to mosaic and leafroll. The pattern of seed generation effects of selected potato varieties on mosaic and blackleg incidence was inconsistent across inspection years. In addition, we observed a significant negative correlation between the relative abundance of the green peach aphid, Myzus persicae, and mosaic in winter inspections. Mosaic incidences in summer and leafroll incidences were not influenced by common aphid species captured or total aphids in the valley. These results identify mosaic and blackleg as major causes of seed potato rejections and downgrades, sensitive and tolerant varieties, and provide suggestions for improving integrated crop management practices in Colorado.


Assuntos
Doenças das Plantas , Solanum tuberosum , Animais , Certificação , Colorado , Análise de Dados , Modelos Logísticos , Modelos Teóricos , Doenças das Plantas/genética , Doenças das Plantas/microbiologia , Doenças das Plantas/virologia , Sementes , Solanum tuberosum/microbiologia , Solanum tuberosum/normas , Solanum tuberosum/virologia
13.
Viruses ; 10(9)2018 09 17.
Artigo em Inglês | MEDLINE | ID: mdl-30227597

RESUMO

Viroids are circular noncoding RNAs that infect plants. Without encoding any protein, these noncoding RNAs contain the necessary genetic information for propagation in hosts. Nuclear-replicating viroids employ DNA-dependent RNA polymerase II (Pol II) for replication, a process that makes a DNA-dependent enzyme recognize RNA templates. Recently, a splicing variant of transcription factor IIIA (TFIIIA-7ZF) was identified as essential for Pol II to replicate potato spindle tuber viroid (PSTVd). The expression of TFIIIA-7ZF, particularly the splicing event, is regulated by a ribosomal protein (RPL5). PSTVd modulates its expression through a direct interaction with RPL5 resulting in optimized expression of TFIIIA-7ZF. This review summarizes the recent discoveries of host factors and regulatory mechanisms underlying PSTVd-templated transcription processes and raises new questions that may help future exploration in this direction. In addition, it briefly compares the machinery and the regulatory mechanism for PSTVd with the replication/transcription system of human hepatitis delta virus.


Assuntos
Regulação Viral da Expressão Gênica , Interações Hospedeiro-Patógeno , Doenças das Plantas/virologia , RNA Viral , Solanum tuberosum/virologia , Transcrição Genética , Viroides/fisiologia , Conformação de Ácido Nucleico , Doenças das Plantas/genética , Processamento de RNA , RNA Viral/química , RNA Viral/genética , Proteínas Ribossômicas/genética , Proteínas Ribossômicas/metabolismo , Fator de Transcrição TFIIIA/genética , Fator de Transcrição TFIIIA/metabolismo , Replicação Viral
14.
Int J Mol Sci ; 19(8)2018 Aug 04.
Artigo em Inglês | MEDLINE | ID: mdl-30081556

RESUMO

One type of monitoring system in a plant cell is the cell wall, which intensively changes its structure during interaction with pathogen-stress factors. The wall plays a role as a dynamic and controlled structure, although it is not fully understood how relevant these modifications are to the molecular mechanisms during plant⁻virus interactions. In this work we localise the non-cellulosic polysaccharides such as xyloglucan, xylan (xylan-1) and xyloglucosyl transferase (XTH-Xet5), the enzyme that participates in the metabolism of xyloglucan. This provided us with information about the in situ distribution of the components of the hemicellulotic cell wall matrix in hypersensitive and susceptible potato⁻PVYNTN interactions. The loosening of the cell wall was accompanied by an increase in xylan depositions during susceptible interactions, whereas, during the hypersensitive response, when the cell wall was reinforced, the xylan content decreased. Moreover, the PVY inoculation significantly redirected XTH-Xet5 depositions, regardless of types of interactions, compared to mock-inoculated tissues. Furthermore, the immunogold localisation clearly revealed the domination of Xet5 in the cell wall and in vesicles in the susceptible host. In contrast, in the resistant host increased levels of Xet5 were observed in cytoplasm, in the cell wall and in the trans-Golgi network. These findings show that the hypersensitive reaction activated XTH-Xet5 in the areas of xyloglucan endo-transglycosylase (XET) synthesis, which was then actively transported to cytoplasm, cell wall and to vacuoles. Our results provide novel insight into cell wall reorganisation during PVYNTN infection as a response to biotic stress factors. These novel findings help us to understand the mechanisms of defence responses that are incorporated into the cell wall signalling network.


Assuntos
Parede Celular/metabolismo , Glucanos/metabolismo , Glicosiltransferases/metabolismo , Proteínas de Plantas/metabolismo , Potyvirus/patogenicidade , Solanum tuberosum/metabolismo , Solanum tuberosum/virologia , Xilanos/metabolismo , Doenças das Plantas/virologia
15.
Arch Virol ; 163(11): 3073-3081, 2018 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-30097746

RESUMO

In plants, viral replication can be inhibited through gene silencing, which is mediated by short interfering RNA (siRNA) or microRNA (miRNA). However, under natural conditions, viruses are extremely susceptible to mutations that may decrease the efficiency of cleavage of these small RNAs (sRNAs). Therefore, a single sRNA may not provide a sufficient degree of viral resistance to transgenic plants. Potato virus Y necrotic strain (PVYN) and Potato virus Y common strain (PVYO) are the two major PVY strains that cause systemic necrosis and mottling, respectively, in tobacco. In this study, we designed specific siRNAs and miRNAs to target two regions of the PVYO replicase gene (NIb). Eight plant expression vectors containing one or two sRNAs were constructed. Luciferase activity assays showed that the designed sRNAs successfully cleaved the NIb gene of PVYO and PVYN, and the vector carrying a combined siRNA- and miRNA-based short hairpin RNA (shRNA) demonstrated the strongest inhibitory effect. These effects were confirmed through the acquisition of PVYO and PVYN resistance in transgenic sRNA-expressing Nicotiana tabacum plants. This phenomenon could be related to a plant defense mechanism in which siRNA and miRNA pathways are complementary and interact to achieve gene silencing. Furthermore, there is a tendency for the homologous small RNA sequences (PVYO) to be more effective in conferring resistance than those with imperfect homology (PVYN). Overall, these findings confirm that the use of a combined siRNA- and miRNA-based shRNAs is a promising approach for introducing viral resistance to plants through genetic engineering.


Assuntos
MicroRNAs/genética , Doenças das Plantas/virologia , Potyvirus/genética , RNA Replicase/genética , RNA Interferente Pequeno/genética , Solanum tuberosum/virologia , Proteínas Virais/genética , Replicação Viral , MicroRNAs/metabolismo , Doenças das Plantas/imunologia , Potyvirus/enzimologia , Potyvirus/fisiologia , Interferência de RNA , RNA Replicase/metabolismo , RNA Interferente Pequeno/metabolismo , Solanum tuberosum/imunologia , Tabaco/imunologia , Tabaco/virologia , Proteínas Virais/metabolismo
16.
Theor Appl Genet ; 131(9): 1925-1938, 2018 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-29855674

RESUMO

KEY MESSAGE: We have elucidated the Andigena origin of the potato Ryadg gene on chromosome XI of CIP breeding lines and developed two marker assays to facilitate its introgression in potato by marker-assisted selection. Potato virus Y (PVY) is causing yield and quality losses forcing farmers to renew periodically their seeds from clean stocks. Two loci for extreme resistance to PVY, one on chromosome XI and the other on XII, have been identified and used in breeding. The latter corresponds to a well-known source of resistance (Solanum stoloniferum), whereas the one on chromosome XI was reported from S. stoloniferum and S. tuberosum group Andigena as well. To elucidate its taxonomic origin in our breeding lines, we analyzed the nucleotide sequences of tightly linked markers (M45, M6) and screened 251 landraces of S. tuberosum group Andigena for the presence of this gene. Our results indicate that the PVY resistance allele on chromosome XI in our breeding lines originated from S. tuberosum group Andigena. We have developed two marker assays to accelerate the introgression of Ryadg gene into breeding lines by marker-assisted selection (MAS). First, we have multiplexed RYSC3, M6 and M45 DNA markers flanking the Ryadg gene and validated it on potato varieties with known presence/absence of the Ryadg gene and a progeny of 6,521 individuals. Secondly, we developed an allele-dosage assay particularly useful to identify multiplex Ryadg progenitors. The assay based on high-resolution melting analysis at the M6 marker confirmed Ryadg plex level as nulliplex, simplex and duplex progenitors and few triplex progenies. These marker assays have been validated and can be used to facilitate MAS in potato breeding.


Assuntos
Resistência à Doença/genética , Doenças das Plantas/genética , Potyvirus , Solanum tuberosum/genética , Alelos , Sequência de Bases , Cromossomos de Plantas , DNA de Plantas/genética , Dosagem de Genes , Loci Gênicos , Marcadores Genéticos , Melhoramento Vegetal , Doenças das Plantas/virologia , Seleção Genética , Solanum tuberosum/virologia
17.
Viruses ; 10(5)2018 05 15.
Artigo em Inglês | MEDLINE | ID: mdl-29762480

RESUMO

Viroids are small non-capsidated non-coding RNA replicons that utilize host factors for efficient propagation and spread through the entire plant. They can incite specific disease symptoms in susceptible plants. To better understand viroid-plant interactions, we employed microarray analysis to observe the changes of gene expression in "Rutgers" tomato leaves in response to the mild (M) and severe (S23) variants of potato spindle tuber viroid (PSTVd). The changes were analyzed over a time course of viroid infection development: (i) the pre-symptomatic stage; (ii) early symptoms; (iii) full spectrum of symptoms and (iv) the so-called 'recovery' stage, when stem regrowth was observed in severely affected plants. Gene expression profiles differed depending on stage of infection and variant. In S23-infected plants, the expression of over 3000 genes was affected, while M-infected plants showed 3-fold fewer differentially expressed genes, only 20% of which were specific to the M variant. The differentially expressed genes included many genes related to stress; defense; hormone metabolism and signaling; photosynthesis and chloroplasts; cell wall; RNA regulation, processing and binding; protein metabolism and modification and others. The expression levels of several genes were confirmed by nCounter analysis.


Assuntos
Perfilação da Expressão Gênica , Regulação da Expressão Gênica de Plantas , Lycopersicon esculentum/virologia , Doenças das Plantas/genética , Solanum tuberosum/virologia , Viroides/patogenicidade , Ontologia Genética , Genes de Plantas/genética , Interações Hospedeiro-Patógeno , Análise de Sequência com Séries de Oligonucleotídeos , Doenças das Plantas/virologia , Folhas de Planta/virologia , RNA Viral/análise , Reprodutibilidade dos Testes , Fatores de Tempo , Viroides/fisiologia
18.
Environ Entomol ; 47(3): 654-659, 2018 06 06.
Artigo em Inglês | MEDLINE | ID: mdl-29617985

RESUMO

This study establishes the effect of Potato Virus Y (PVY; Potyvirus) in potatoes, Solanum tuberosum L. (Solanales: Solanaceae) and in common-lambs' quarter Chenopodium album L. (Amaranthaceae) on Macrosiphum euphorbiae Thomas (Hemiptera: Aphididae) and Myzus persicae Sulzer (Hemiptera: Aphididae) behavior, host preference, transmission, and fitness under field and laboratory studies. In the field, several weeds, besides C. album, were collected, including: Sisymbrium altissimum L. (Brassicaceae), Erodium cicutarium L., Lactuca serriola L., Solanum sarrachoides Sendtner (Solanaceae), and S. dulcamara L. (Solanaceae). All weeds were serologically tested for the presence of PVY. From all weeds collected, 2.3 and 34% of C. album and S. sarrachoides, respectively, were PVY-positive. From those positive samples, 72% of the PVY found were PVYN; the remaining 28% was PVYO. In addition, several aphid species were collected from those weeds: Ovatus crataegarious Walker, Macrosiphum euphorbiae (Hemiptera: Aphididae), Hyalopterus pruni Geoffroy (Hemiptera: Aphididae), Rophalosiphum madis Fitch, and 'others aphid' species were collected. The highest number of aphids were collected in E. cicutarium, followed by S. dulcamara, L. serriola, S. altissimum, and C. album. In laboratory studies, PVY-infected C. album does not induce the production of aphids. Moreover, M. persicae did not appear to have a strong preference for either healthy or PVY-infected potato plant, but they did develop a preference for infected plants after prolonged feeding. M. persicae and M. euphorbiae transmitted PVY from C. album to S. tuberosum, 44 and 37.5 % of the time. Future research should seek to identify not only other sources and prevalence of PVY in the field but vector relationships. In insect-pathogen complex continues to persist in solanaceous field crops around the world.


Assuntos
Afídeos/fisiologia , Chenopodium album/virologia , Cadeia Alimentar , Doenças das Plantas/virologia , Potyvirus/fisiologia , Solanum tuberosum/virologia , Animais , Afídeos/genética , Afídeos/virologia , Aptidão Genética , Especificidade da Espécie
19.
Arch Virol ; 163(6): 1585-1594, 2018 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-29492653

RESUMO

A novel virus was discovered in a freeze-dried collection held at SASA, UK, originating from potato (Solanum tuberosum) cv. Nadine. The complete sequence of the viral RNA was determined to be 3674 nucleotides in length encoding five predicted proteins. Based on the deduced genome organization and phylogenetic analysis, this virus represents a putative new member of the genus Alphanecrovirus, family Tombusviridae, most closely related to isolates of Olive mild mosaic virus. The virus was easily transmitted to indicator plants with symptoms that were slower to develop and less severe than those of related viruses. To distinguish this virus, the clearest symptom differences occurred with Nicotiana debneyi, Chenopodium amaranticolor and Ch. quinoa. The virus was detected with antisera to the related viruses tobacco necrosis virus A and tobacco necrosis virus D. The close association to the tobacco necrosis viruses would suggest this virus is not a new introduction to potato but in the past has been misidentified as one of these viruses. The virus isolate has been named potato necrosis virus.


Assuntos
Genoma Viral , Filogenia , RNA Viral/genética , Solanum tuberosum/virologia , Tombusviridae/genética , Chenopodium/virologia , Chenopodium quinoa/virologia , Efeito Fundador , Fases de Leitura Aberta , Doenças das Plantas/virologia , Tabaco/virologia , Tombusviridae/classificação , Tombusviridae/isolamento & purificação , Tombusviridae/patogenicidade , Reino Unido
20.
Int J Mol Sci ; 19(3)2018 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-29543714

RESUMO

The cell wall provides the structure of the plant, and also acts as a barier against biotic stress. The vein necrosis strain of Potato virus Y (PVYNTN) induces necrotic disease symptoms that affect both plant growth and yield. Virus infection triggers a number of inducible basal defense responses, including defense proteins, especially those involved in cell wall metabolism. This study investigates the comparison of cell wall host dynamics induced in a compatible (potato cv. Irys) and incompatible (potato cv. Sárpo Mira with hypersensitive reaction gene Ny-Smira) PVYNTN-host-plant interaction. Ultrastructural analyses revealed numerous cell wall changes induced by virus infection. Furthermore, the localization of essential defensive wall-associated proteins in susceptible and resistant potato host to PVYNTN infection were investigated. The data revealed a higher level of detection of pathogenesis-related protein 2 (PR-2) in a compatible compared to an incompatible (HR) interaction. Immunofluorescence analyses indicated that hydroxyproline-rich glycoproteins (HRGP) (extensin) synthesis was induced, whereas that of cellulose synthase catalytic subunits (CesA4) decreased as a result of PVYNTN infection. The highest level of extensin localization was found in HR potato plants. Proteins involved in cell wall metabolism play a crucial role in the interaction because they affect the spread of the virus. Analysis of CesA4, PR-2 and HRGP deposition within the apoplast and symplast confirmed the active trafficking of these proteins as a step-in potato cell wall remodeling in response to PVYNTN infection. Therefore, cell wall reorganization may be regarded as an element of "signWALLing"-involving apoplast and symplast activation as a specific response to viruses.


Assuntos
Parede Celular/ultraestrutura , Interações Hospedeiro-Patógeno , Potyvirus/patogenicidade , Solanum tuberosum/virologia , Parede Celular/metabolismo , Parede Celular/virologia , Glucosiltransferases/metabolismo , Glicoproteínas/metabolismo , Proteínas de Plantas/metabolismo , Solanum tuberosum/genética , Solanum tuberosum/metabolismo
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