Virology Commons^™

Bean Yellow Mosaic Virus And Its Management In Lupins, Department Of Primary Industries And Regional Development, Western Australia

Grains and other field crops factsheets

Bean yellow mosaic virus (BYMV) is an aphid-transmitted virus that commonly causes necrotic symptoms that kills lupin plants when infected early before pod set. When plants are infected after pod set, black pods develop (known as black pod syndrome).

BYMV is found predominantly in high rainfall areas of the Western Australian (WA) grainbelt. This page outlines the symptoms, diagnosis, factors favouring disease risk and spread, yield and quality impacts, and management for BYMV in lupin crops in WA

Cucumber Mosaic Virus And Its Management In Narrow Leafed Lupins, Department Of Primary Industries And Regional Development, Western Australia

Grains and other field crops factsheets

Cucumber mosaic virus (CMV) is a seed- and aphid-borne virus that infects narrow-leafed lupins. Western Australian (WA) grainbelt regions most at risk are the high rainfall zones of the northern and central agricultural region and the south coastal region.

The principal infection source for lupin crops is sowing infected lupin seed.

Wheat Streak Mosaic Virus And Wheat Curl Mite And Their Management, Department Of Primary Industries And Regional Development, Western Australia

Grains and other field crops factsheets

Wheat streak mosaic virus (WSMV) is a seed and mite-borne virus that infects wheat, causing severe leaf symptoms and reduced yields. The symptoms and damage are more severe in wheat than other hosts, in which infection is symptomless.

Wheat streak mosaic virus can cause crop failure when widespread infection occurs in seedling wheat, particularly when a heavily WSMV-infected green bridge is not controlled before sowing an early crop, and warm temperatures favour mites.

Wheat curl mite (Aceria tosichella) is the only known vector of WSMV. It can transmit the virus in its nymph and adult stages.

Role Of Autophagy-Related Genes In Lipid Transport For Efficient Replication Of Tombusviruses, Yuanrong Kang

Theses and Dissertations--Plant Pathology

Tombusviruses are positive-strand RNA viruses, which utilize numerous co-opted host factors and massive de-novo synthesized membrane resources to modify host membranes and form large viral replication organelles (VROs). Among plenty of host cellular processes, autophagy emerges as a potential membrane resource for VROs formation due to its ability to de-novo generate the double membrane structures, known as autophagosomes. Besides, as an important host defense pathway, autophagy is also a target for tombusviruses to prevent its antiviral activities. In this study, I identify the role of key autophagy related genes, Atg11, Atg8, and Atg2, which are involved in autophagosome formation, and …

The Quest To Identify A New Virus Disease Of Sunflower From Nebraska, Robert M. Harveson, Maher Al Rwahnih, California Department Of Food And Agriculture, Alex Karasev, Tom J. Gulya, Jeff Bradshaw

Panhandle Research and Extension Center

Between 2010 and 2018, sunflower plants exhibiting virus-like symptoms, including stunting, mottling, and chlorotic ringspots on leaves, were observed from commercial fields and research plots from four sites within three distinct counties of western Nebraska (Box Butte, Kimball, and Scotts Bluff). Near identical symptoms from field samples were reproduced on seedlings mechanically in the greenhouse on multiple occasions, confirming the presence of a sap-transmissible virus from each site. Symptomatic greenhouse-inoculated plants from the 2010 and 2011 Box Butte samples tested negative for sunflower mosaic virus (SuMV), sunflower chlorotic mottle virus (SuCMoV), and all potyviruses in general by ELISA and RT-PCR. …

The Roles Of The Actin Network And Co-Opted Host Factors In Tbsv Replication, Melissa Gabriela Molho Medina

Theses and Dissertations--Plant Pathology

Positive-stranded (+) RNA viruses are the largest family of viruses that infect plants, causing important economic losses in different crops. Tomato bushy stunt virus (TBSV), a small positive-stranded RNA virus, has emerged as a model virus to study virus-host interactions. TBSV encodes for only five proteins, therefore, to infect the host cell TBSV co-opts selected host components and subverts specific molecular pathways.

Firstly, I performed a proteomic screening using Arabidopsis proteins. I found that TBSV viral replication proteins interact with 88 host proteins, including the ubiquitin-conjugating enzyme 2 (Ubc2), fructose 1,6 biphosphate aldolase (Fba1), and several members of the Hps70 …

Polerovirus Genomic Variation And Mechanisms Of Silencing Suppression By P0 Protein, Natalie Holste

School of Biological Sciences: Dissertations, Theses, and Student Research

The family Luteoviridae consists of three genera: Luteovirus, Enamovirus, and Polerovirus. The genus Polerovirus contains 32 virus species. All are transmitted by aphids and can infect a wide variety of crops from cereals and wheat to cucurbits and peppers. However, little is known about how this wide range of hosts and vectors developed. In poleroviruses, aphid transmission and virion formation is mediated by the coat protein read-through domain (CPRT) while silencing suppression and phloem limitation is mediated by Protein 0 (P0)—a protein unique to poleroviruses. P0 gives poleroviruses a great advantage amongst plant viruses and diversifies polerovirus species, but the …

Mechanisms Of Silencing Suppression By A Polerovirus P0 Protein, Natalie Holste, Hernan Garcia-Ruiz

School of Biological Sciences: Presentations

Maize lethal necrosis is an intense viral disease spreading across sub-Saharan Africa. Maize is the staple crop grown in sub-Saharan Africa, but most crops infected with maize lethal necrosis will not survive to harvest. This causes immense economic hardship and starvation within the population. Maize lethal necrosis consists of a combination of two viruses, Maize chlorotic mottle virus (MCMV) and a virus from the genus potyvirus. In a recent study, a Maize yellow dwarf virus-RMV (MYDV-RMV)-like polerovirus, was repeatedly detected in plants with maize lethal necrosis. Poleroviruses have a silencing suppressor, P0 protein, and the mechanism of suppression is poorly …

Virus-Induced Changes In Nuclear Proteins And Membranes In Nicotiana Benthamiana Cells, Caleb Mathias

Theses and Dissertations--Plant Pathology

Viruses rely on host proteins to complete their life cycles. This results in alterations to normal cell physiology to processes which benefit viral processes such as replication and movement to other cells. This may involve the relocalization of host proteins away from their original subcellular targets to sites which may benefit the virus, a process that is not as well understood as it relates to the nucleus. To identify nuclear proteins that may be involved in such processes, a library of random Nicotiana benthamiana cDNAs were expressed as GFP fusions in a transgenic marker lines expressing a histone 2B:RFP nuclear …

Strain-Specific Protein Interaction And Localization Of Two Strains Of Potato Yellow Dwarf Virus And Functional Domains Of Their Matrix Protein, Chanyong Jang

Theses and Dissertations--Plant Pathology

Potato yellow dwarf virus (PYDV) is the type species of the genus nucleorhabdovirus which is typified by its nucleotropic characters of the members. The virus accomplishes its replication and morphogenesis in the nuclei of infected cells. Two strains, Constricta strain (CYDV) and Sanguinolenta strain (SYDV) have been described at the level of vector-specificity. CYDV is vectored by Agallia constricta and SYDV is transmitted by Aceratagllia sanguinolenta. The full-length genome of CYDV was sequenced. The 12,792 nt antisense genome encodes seven open reading frames in the order of, nucleocapsid protein (N), unknown protein (X), phosphoprotein (P), movement protein (Y), matrix …

Grapevine Vein Clearing Virus: Epidemiological Patterns And Construction Of A Clone, Cory Von Keith

Graduate Theses/Dissertations

Grapevine vein clearing virus (GVCV) is a recently discovered virus belonging to the Badnavirus genus. Characteristic to its name, the virus is associated with a disease where symptoms manifest as pronounced vein-clearing, resulting in severe berry deformation and vine decline in susceptible grape varieties. Sustainable production of wine is dependent on healthy plants. The associated disease is mainly found in Midwest vineyards. Attempts were made in this thesis to provide evidence of causality of the virus to the associated disease and to infer the historical path and migration pattern of GVCV. Conclusions and discussions will provide grape producers with the …

Binding Of Maize Necrotic Streak Virus (Mnesv) 3’ I-Shaped Structure (3’ Iss) To Eukaryotic Translation Factors (Eifs) And Implication In Eif4f Mediated Translation Initiation, Qiao Liu

Dissertations, Theses, and Capstone Projects

5' m⁷GpppN cap and the 3' poly adenosine (A) tail of eukaryotic mRNAs are key elements for recruiting translation initiation machinery in canonical translation initiation. Unlike host mRNAs, many viruses lack these elements and yet they are translated efficiently. Plant viruses, in particular, have complex structures within their untranslated regions (UTR) that allow them to bypass some cellular translation control steps. In Maize necrotic streak virus (MNeSV) 3' UTR, an I-Shaped RNA Structure (ISS) has been reported to mediate the virus translation initiation progress. 3’ ISS binding with eIF4F has been shown to facilitate translation. 5’ -3’ kissing …

Sweetpotato Virus C And Its Contribution To The Potyvirus Complex In Sweetpotato (Ipomoea Batatas), Favio E. Herrera Eguez

LSU Doctoral Dissertations

In Louisiana, sweetpotato (Ipomoea batatas) is infected in Louisiana by the four ubiquitous potyviruses: Sweetpotato feathery mottle virus (SPFMV), Sweetpotato virus G (SPVG), Sweetpotato virus 2 (SPV2) and the strain of SPFMV previously known as the common strain, recently renamed as Sweetpotato virus C (SPVC). These four viruses belong to the Potyviridae family, with single stranded RNA of ~11kb. In this group of plant viruses, a single polyprotein is coded entirely but later cleaved into ten mature proteins: P1, HC-pro, P3, 6K1, CI, 6K2, NIa-VPg, NIa-Pro Nib and Coat Protein (CP). In sweetpotato potyviruses, two additional open reading …

Detection And Epidemic Dynamic Of Tocv And Ccyv With Bemisia Tabaci And Weed In Hainan Of China, Xin Tang, Xiaobin Shi, Deyong Zhang, Fan Li, Fei Yan, Youjun Zhang, Yong Liu, Xuguo Zhou

Entomology Faculty Publications

Background: In recent years, two of the crinivirus, Tomato chlorosis virus (ToCV) and Cucurbit chlorotic yellows virus (CCYV) have gained increasing attention due to their rapid spread and devastating impacts on vegetable production worldwide. Both of these viruses are transmitted by the sweet potato whitefly, Bemisia tabaci (Gennadius), in a semi-persistent manner. Up to now, there is still lack of report in Hainan, the south of China.

Methods: We used observational and experimental methods to explore the prevalence and incidence dynamic of CCYV and ToCV transmitted by whiteflies in Hainan of China.

Results: In 2016, the chlorosis symptom was observed …

Genome Sequence Variation In The Constricta Strain Dramatically Alters The Protein Interaction And Localization Map Of Potato Yellow Dwarf Virus, Chanyong Jang, Renyuan Wang, Joseph Wells, Fabian Leon, Mark Farman, John Hammond, Michael M. Goodin

Plant Pathology Faculty Publications

The genome sequence of the constricta strain of Potato yellow dwarf virus (CYDV) was determined to be 12 792 nt long and organized into seven ORFs with the gene order 3′-N-X-P-Y-M-G-L-5′, which encodes the nucleocapsid, phospho, movement, matrix, glyco, and RNA-dependent RNA polymerase proteins, respectively, except for X, which is of unknown function. Cloned ORFs for each gene, except L, were used to construct a protein interaction and localization map (PILM) for this virus, which shares greater than 80 % amino acid similarity in all ORFs except X and P with the sanguinolenta strain of this species (SYDV). Protein localization …

Sterol Binding By The Tombusviral Replication Proteins Is Essential For Replication In Yeast And Plants, Kai Xu, Peter D. Nagy

Plant Pathology Faculty Publications

Membranous structures derived from various organelles are important for replication of plus-stranded RNA viruses. Although the important roles of co-opted host proteins in RNA virus replication have been appreciated for a decade, the equally important functions of cellular lipids in virus replication have been gaining full attention only recently. Previous work with Tomato bushy stunt tombusvirus (TBSV) in model host yeast has revealed essential roles for phosphatidylethanolamine and sterols in viral replication. To further our understanding of the role of sterols in tombusvirus replication, in this work we showed that the TBSV p33 and p92 replication proteins could bind to …

Detecting, Cloning, And Screening For Suppressors Of Rna Silencing In Maize Chlorotic Mottle Virus And Sugarcane Mosaic Virus, Nicole E. Bacheller

Department of Agronomy and Horticulture: Dissertations, Theses, and Student Research

Maize lethal necrosis disease (MLND) is one of the most important viral diseases of maize. MLND occurs when Maize chlorotic mottle virus (MCMV) co-infects the same plant with one of several potyviruses, including Sugarcane mosaic virus, Wheat streak mosaic virus or Maize dwarf mosaic virus. Originally prevalent in the Midwest and Peru in the 1970s, the disease was called corn lethal necrosis (CLN) and was controlled through breeding and sanitation. Recently, the disease has re-emerged in East Africa and is rapidly spreading and threatening the food sources of subsistence-farming populations. This re-emergence has raised several questions about the unknown …

Heterodimers As The Structural Unit Of The T=1 Capsid Of The Fungal Double-Stranded Rna Rosellinia Necatrix Quadrivirus 1, Daniel Luque, Carlos P. Mata, Fernando González-Camacho, José M. González, Josué Gómez-Blanco, Carlos Alfonso, Germán Rivas, Wendy M. Havens, Satoko Kanematsu, Nobuhiro Suzuki, Said A. Ghabrial, Benes L. Trus, José R Castón

Plant Pathology Faculty Publications

Most double-stranded RNA (dsRNA) viruses are transcribed and replicated in a specialized icosahedral capsid with a T=1 lattice consisting of 60 asymmetric capsid protein (CP) dimers. These capsids help to organize the viral genome and replicative complex(es). They also act as molecular sieves that isolate the virus genome from host defense mechanisms and allow the passage of nucleotides and viral transcripts. Rosellinia necatrix quadrivirus 1 (RnQV1), the type species of the family Quadriviridae, is a dsRNA fungal virus with a multipartite genome consisting of four monocistronic segments (segments 1 to 4). dsRNA-2 and dsRNA-4 encode two CPs (P2 and …

Identification Of Diverse Mycoviruses Through Metatranscriptomics Characterization Of The Viromes Of Five Major Fungal Plant Pathogens, Shin-Yi Lee Marzano, Berlin D. Nelson, Olutoyosi Ajayi-Oyetunde, Carl A. Bradley, Teresa J. Hughes, Glen L. Hartman, Darin M. Eastburn, Leslie L. Domier

Plant Pathology Faculty Publications

Mycoviruses can have a marked effect on natural fungal communities and influence plant health and productivity. However, a comprehensive picture of mycoviral diversity is still lacking. To characterize the viromes of five widely dispersed plant-pathogenic fungi, Colletotrichum truncatum, Macrophomina phaseolina, Diaporthe longicolla, Rhizoctonia solani, and Sclerotinia sclerotiorum, a high-throughput sequencing-based metatranscriptomic approach was used to detect viral sequences. Total RNA and double-stranded RNA (dsRNA) from mycelia and RNA from samples enriched for virus particles were sequenced. Sequence data were assembled de novo, and contigs with predicted amino acid sequence similarities to viruses in the …

Antiviral Rna Silencing Suppression Activity Of Tomato Spotted Wilt Virus Nss Protein, Tania Ocampo Ocampo, Sergio M. Gabriel Peralta, Nicole Bacheller, Stella Uiterwaal, Aaron Knapp, Alanna Hennen, Daniel Leobardo Ochoa-Martínez, Hernan Garcia-Ruiz

Department of Plant Pathology: Faculty Publications

In addition to regulating gene expression, RNA silencing is an essential antiviral defense system in plants. Triggered by double-stranded RNA, silencing results in degradation or translational repression of target transcripts. Viruses are inducers and targets of RNA silencing. To condition susceptibility, most plant viruses encode silencing suppressors that interfere with this process, such as the Tomato spotted wilt virus (TSWV) NSs protein. The mechanism by which NSs suppresses RNA silencing and its role in viral infection and movement remain to be determined. We cloned NSs from the Hawaii isolate of TSWV and using two independent assays show for the first …

Role Of Viral Rna And Co-Opted Cellular Escrt-I And Escrt-Iii Factors In Formation Of Tombusvirus Spherules Harboring The Tombusvirus Replicase, Nikolay Kovalev, Isabel Fernández De Castro Martín, Judit Pogany, Daniel Barajas, Kunj Bihari Pathak, Cristina Risco, Peter D. Nagy

Plant Pathology Faculty Publications

Plus-stranded RNA viruses induce membrane deformations in infected cells in order to build viral replication complexes (VRCs). Tomato bushy stunt virus (TBSV) co-opts cellular ESCRT (endosomal sorting complexes required for transport) proteins to induce the formation of vesicle (spherule)-like structures in the peroxisomal membrane with tight openings toward the cytosol. In this study, using a yeast (Saccharomyces cerevisiae) vps23Δ bro1Δ double-deletion mutant, we showed that the Vps23p ESCRT-I protein (Tsg101 in mammals) and Bro1p (ALIX) ESCRT-associated protein, both of which bind to the viral p33 replication protein, play partially complementary roles in TBSV replication in cells …

Understanding The Causal Agent Of Rose Rosette Disease, Patrick Louis Di Bello

Graduate Theses and Dissertations

A number viruses are known to infect roses, ranging from those in the genera Nepovirus, and Ilarvirus, which have been reported since the inception of rose virology, to recently discovered viruses in the genera Carmovirus, Closterovirus, Emaravirus, Luteovirus, Rosadnavirus, and Potyvirus. Of the viral diseases in rose, arguably the most damaging is Rose rosette (RRD), which is associated with the Emaravirus, Rose rosette virus (RRV). The objective of this thesis is to fill in the gaps in knowledge on the epidemiological aspects of RRD and RRV. There has been significant progress in the epidemiology of the RRD agent prior to …

The Phenotypic Effects And Transcript Response Of Salt Stress, The Impact Of Viral Infection On Salt Stress Symptoms, And The Effect Of Salt Stress On Soybean Virus Vector Activity In Soybean Varieties That Vary In Chloride Uptake, Alma Glenn Laney

Graduate Theses and Dissertations

With the increase in saline soils worldwide, understanding the mechanisms for salt tolerance in plants is important to reduce yield loss due to salt stress. Soybean, Glycine max (L.) Merr., genotypes differ in chloride uptake with genotypes that take up chloride into foliar tissues tending to be salt-sensitive whereas those that partially exclude chloride from the leaves are more salt-tolerant. Transcriptional and physiological responses were measured in two soybean cultivars, Clark and Manokin, which differ in chloride uptake in response to salt stress and in combination with Soybean mosaic virus (SMV) and its aphid vector, Aphis glycines . The interaction …

Population Dynamics Of Triticum Mosaic Virus In Various Host Species, Melissa S. Bartels

Department of Agronomy and Horticulture: Dissertations, Theses, and Student Research

It has been established that RNA viruses should be genetically diverse, due to the high error rate of their RNA-dependent RNA polymerases and the lack of proof-reading capabilities. Plant RNA viruses are not as genetically diverse as expected. Evolutionary factors, such as purifying selection and bottlenecks that favor genetic stability, might be affecting plant viral populations. Otherwise RNA virus populations, with their potential for extreme diversity, might acquire a lethal number of mutations leading to the collapse of the population.

Triticum mosaic virus (TriMV) populations maintained in a controlled greenhouse environment displayed genetic stability. The mutation frequency per nucleotide of …

Phages Of Non-Diary Lactococci: Isolation And Characterization Of Phi L47, A Phage Infecting The Grass Isolate Lactococcus Lactis Ssp Cremoris Dpc6860, Daniel Cavanagh, Caitríona M. Guinane, Horst Neve, Aidan Coffey, R. Paul Ross, Gerald F. Fitzgerald, Olivia Mcauliffe

Department of Biological Sciences Publications

Lactococci isolated from non-dairy sources have been found to possess enhanced metabolic activity when compared to dairy strains. These capabilities may be harnessed through the use of these strains as starter or adjunct cultures to produce more diverse flavor profiles in cheese and other dairy products. To understand the interactions between these organisms and the phages that infect them, a number of phages were isolated against lactococcal strains of non-dairy origin. One such phage, ΦL47, was isolated from a sewage sample using the grass isolate L. lactis ssp. cremoris DPC6860 as a host. Visualization of phage virions by transmission electron …

Key Roles Of Sub-Cellular Membranes And Co-Chaperone In Tombusvirus Replication, Kai Xu

Theses and Dissertations--Plant Pathology

Positive strand RNA viruses, inculding tombusviruses, are known to utilize cellular membranes to assemble their replicase complexes (VRCs). Two tombusviruses , Tomato bushy stunt virus (TBSV) and Carnation Italian ringspot virus (CIRV), replicate on different organellar membranes, peroxisomes or endoplasmic reticulum (ER) for TBSV and mitochodria outer membranes in case of CIRV. I showed that both TBSV and CIRV replicase proteins could assemble VRCs and replicate viral RNA on purified microsomes (ER) and mitochondria. Different efficiencies of assembly was shown determined by multiple domains on TBSV or CIRV replication proteins.

To study why VRC assembly could occur on an alternative …

Rna Sequence Determinants Of A Coupled Termination-Reinitiation Strategy For Translation Of Downstream Orf In Helminthosporium Victoriae Virus 190s And Other Victoriviruses (Family Totiviridae), Hua Li

Theses and Dissertations--Plant Pathology

Double-stranded RNA fungal virus Helminthosporium victoriae virus 190S (genus Victorivirus, family Totiviridae) contains two large open reading frames (ORFs) that overlap in the tetranucleotide AUGA. Translation of the downstream ORF, which encodes the RNA-dependent RNA polymerase (RdRp), was previously proposed to depend on ribosomal reinitiation following termination of the upstream ORF, which encodes the capsid protein. In this study, I provided evidence to confirm that coupled termination-reinitiation (stop-restart) is indeed used. A dual-fluorescence method was established to define the RNA sequence determinants for RdRp translation. Stop-restart depends on a 32-nt stretch of RNA sequence immediately upstream of the …