Plant Pathology Commons^™

An Eriophyid Mite-Transmitted Plant Virus Contains Eight Genomic Rna Segments With Unusual Heterogeneity In The Nucleocapsid Protein, Satyanarayana Tatineni, Anthony J. Mcmechan, Everlyne N. Wosula, Stephen N. Wegulo, Robert A. Graybosch, Roy French, Gary L. Hein

Papers in Plant Pathology

Eriophyid mite-transmitted, multipartite, negative-sense RNA plant viruses with membrane-bound spherical virions are classified in the genus Emaravirus. We report here that the eriophyid mite-transmitted Wheat mosaic virus (WMoV), an Emaravirus, contains eight genomic RNA segments, the most in a known negative-sense RNA plant virus. Remarkably, two RNA 3 consensus sequences, encoding the nucleocapsid protein, were found with 12.5% sequence divergence, while no heterogeneity was observed in the consensus sequences of additional genomic RNA segments. The RNA-dependent RNA polymerase, glycoprotein precursor, nucleocapsid, and P4 proteins of WMoV exhibited limited sequence homology with the orthologous proteins of other emaraviruses, while …

Effects Of Ocean Acidification On Chlorophyll Content, C. Del Fierro, R. Lloyd, H. El-Askary

e-Research: A Journal of Undergraduate Work

Airborne pollutants contribute to ocean acidification and hence to the associated chlorophyll content level. Previous work showed that falling aerosols causing ocean acidification would in turn result in bleaching and productivity loss in coral reef builders. Chlorophyll content has been used as a measure of the concentration of the photosynthetic pigment chlorophyll a (the most common "green" chlorophyll) in the ocean. In our work we have monitored the change in chlorophyll content obtained from the Moderate Resolution Imaging Spectroradiometer (MODIS) sensor on board Terra/Aqua satellites from 2000-2009 over selected pilot areas. Moreover, we have used the Goddard Chemistry Aerosol Radiation …

A Novel Partitivirus That Confers Hypovirulence On Plant Pathogenic Fungi, Xueqiong Xiao, Jiasen Cheng, Jinghua Tang, Yanping Fu, Daohong Jiang, Timothy S. Baker, Said A. Ghabrial, Jiatao Xie

Plant Pathology Faculty Publications

Members of the family Partitiviridae have bisegmented double-stranded RNA (dsRNA) genomes and are not generally known to cause obvious symptoms in their natural hosts. An unusual partitivirus, Sclerotinia sclerotiorum partitivirus 1 (SsPV1/WF-1), conferred hypovirulence on its natural plant-pathogenic fungal host, Sclerotinia sclerotiorum strain WF-1. Cellular organelles, including mitochondria, were severely damaged. Hypovirulence and associated traits of strain WF-1 and SsPV1/WF-1 were readily cotransmitted horizontally via hyphal contact to different vegetative compatibility groups of S. sclerotiorum and interspecifically to Sclerotinia nivalis and Sclerotinia minor. S. sclerotiorum strain 1980 transfected with purified SsPV1/WF-1 virions also exhibited hypovirulence and associated traits similar …

Chlorovirus Skp1-Binding Ankyrin Repeat Protein Interplay And Mimicry Of Cellular Ubiquitin Ligase Machinery, Eric A. Noel, Ming Kang, Jiri Adamec, James L. Van Etten, George A. Oyler

James Van Etten Publications

The ubiquitin-proteasome system is targeted by many viruses that have evolved strategies to redirect host ubiquitination machinery. Members of the genus Chlorovirus are proposed to share an ancestral lineage with a broader group of related viruses, nucleo-cytoplasmic large DNA viruses (NCLDV). Chloroviruses encode an Skp1 homolog and ankyrin repeat (ANK) proteins. Several chlorovirus-encoded ANK repeats contain C-terminal domains characteristic of cellular F-boxes or related NCLDV chordopox PRANC (pox protein repeats of ankyrin at C-terminal) domains. These observations suggested that this unique combination of Skp1 and ANK repeat proteins might form complexes analogous to the cellular Skp1-Cul1-F-box (SCF) ubiquitin ligase complex. …

Diversity Of Bacteria Carried By Pinewood Nematode In Usa And Phylogenetic Comparison With Isolates From Other Countries, Diogo Neves Proença, Luís Fonseca, Thomas Powers, Isabel M.O. Abrantes, Paula V. Morais

Papers in Plant Pathology

Pine wilt disease (PWD) is native to North America and has spread to Asia and Europe. Lately, mutualistic relationship has been suggested between the pinewood nematode (PWN), Bursaphelenchus xylophilus the causal nematode agent of PWD, and bacteria. In countries where PWN occurs, nematodes from diseased trees were reported to carry bacteria from several genera. However no data exists for the United States. The objective of this study was to evaluate the diversity of the bacterial community carried by B. xylophilus, isolated from different Pinus spp. with PWD in Nebraska, United States. The bacteria carried by PWN belonged to Gammaproteobacteria …

Bot Canker Pathogens Could Complicate The Management Of Phytophthora Black Pod Of Cocoa, Idowu Jaiyeola, Rufus J. Akinrinlola, Gbodope S. Ige, Oluwatimilehin O. Omoleye, Abiola Oyedele, Bayode J. Odunayo, Omotayo J. Emehin, Marcus O. Bello, Anthony O. Adesemoye

Papers in Plant Pathology

Black pod is a major hindrance to cocoa production in Nigeria. It is caused by three different Phytophthora species with Phytophthora megakarya as the most important species in Nigeria and West African subregion. Phytophthora spp. may enhance infections by opportunistic pathogens such as members of the Botryosphaeriacea that cause branch and trunk cankers in many woody plants across the world. Botryosphaeriacea has not been reported in cocoa nor in any woody plants in Nigeria to our knowledge. In the cocoa belt of Nigeria, research and understanding on cocoa black pod and Phytophthora is limited partly because of delayed or no …

Tombusvirus-Yeast Interactions Identify Conserved Cell-Intrinsic Viral Restriction Factors, Zsuzsanna Sasvari, Paulina Alatriste Gonzalez, Peter D. Nagy

Plant Pathology Faculty Publications

To combat viral infections, plants possess innate and adaptive immune pathways, such as RNA silencing, R gene and recessive gene-mediated resistance mechanisms. However, it is likely that additional cell-intrinsic restriction factors (CIRF) are also involved in limiting plant virus replication. This review discusses novel CIRFs with antiviral functions, many of them RNA-binding proteins or affecting the RNA binding activities of viral replication proteins. The CIRFs against tombusviruses have been identified in yeast (Saccharomyces cerevisiae), which is developed as an advanced model organism. Grouping of the identified CIRFs based on their known cellular functions and subcellular localization in yeast …

The Hop-Like Stress-Induced Protein 1 Cochaperone Is A Novel Cell-Intrinsic Restriction Factor For Mitochondrial Tombusvirus Replication, Kai Xu, Jing-Yi Lin, Peter D. Nagy

Plant Pathology Faculty Publications

Recent genome-wide screens reveal that the host cells express an arsenal of proteins that inhibit replication of plus-stranded RNA viruses by functioning as cell-intrinsic restriction factors of viral infections. One group of cell-intrinsic restriction factors against tombusviruses contains tetratricopeptide repeat (TPR) domains that directly interact with the viral replication proteins. In this paper, we find that the TPR domain-containing Hop-like stress-inducible protein 1 (Sti1p) cochaperone selectively inhibits the mitochondrial membrane-based replication of Carnation Italian ringspot tombusvirus (CIRV). In contrast, Sti1/Hop does not inhibit the peroxisome membrane-based replication of the closely related Tomato bushy stunt virus (TBSV) or Cucumber necrosis virus …

Phenotypic Diversity In Lysobacter Enzymogenes In Relations To Biological Control, Ya Li

Theses, Dissertations, and Student Research in Agronomy and Horticulture

Strains of the bacterium Lysobacter enzymogenes have been isolated from various regions of the world and reported to have potential as biological control agents against plant pathogens. Previous research revealed many ecological traits and mechanisms important to biological control by L. enzymogenes. Much of the previous research, however, was conducted on individual strains with little direct comparison of different strains. In this study, L. enzymogenes strains isolated from different locations and source materials (soil, roots, leaves) were compared for biocontrol-related phenotypic traits in vitro, epiphytic and endophytic colonization of leaves, and biocontrol of Bipolaris leaf spot on tall fescue. …

Panicum Mosaic Virus Complex And Biofuels Switchgrass, Catherine Louise Stewart

Biological Systems Engineering--Dissertations, Theses, and Student Research

New switchgrass (Panicum virgatum L.) cultivars are being developed for use as a biofuel pyrolysis feedstock. Viral pathogens have been reported in switchgrass, but their importance in biofuel cultivars is not well known. In 2012 surveys of five switchgrass breeding nurseries in Nebraska, plants with mottling and stunting— symptoms associated with virus infection—had an incidence of symptomatic plants within fields as high as 59%. Leaves from 120 symptomatic plants were analyzed by ELISA for Panicum mosaic virus (PMV) and four other viruses known to infect switchgrass. Most samples (87%) were positive for PMV, and fewer than 8% for the …

Evaluating Green Stink Bug Damage And Insect Abundance In Edamame, Benjamin Carroll Thrash

Graduate Theses and Dissertations

Edamame are an emerging crop in Arkansas, with 2013 planting estimates at 680 hectares. Although edamame are the same species as conventional soybeans grown in Arkansas, differences in use, maturity, and harvest may require creation and implementation of insect pest management approaches that differ from those used in conventional soybean production systems in order for a quality crop to be produced. Studies were conducted to determine a green stink bug damage-density relationship for edamame. Cages were used to confine green stink bugs on field-planted edamame at densities of 0, 2, 6, or 12 green stink bugs per cage (0, 0.55, …

Chlorovirus Pbcv-1 Encodes An Active Copper-Zinc Superoxide Dismutase, Ming Kang, Garry A. Duncan, Charles Kuszynski, George Oyler, Jiayin Zheng, Donald F. Becker, James L. Van Etten

James Van Etten Publications

Superoxide dismutases (SODs) are metalloproteins that protect organisms from toxic reactive oxygen species by catalyzing the conversion of superoxide anion to hydrogen peroxide and molecular oxygen. Chlorovirus PBCV-1 encodes a 187-amino-acid protein that resembles a Cu-Zn SOD with all of the conserved amino acid residues for binding copper and zinc (named cvSOD). cvSOD has an internal Met that results in a 165-amino-acid protein (named tcvSOD). Both cvSOD and tcvSOD recombinant proteins inhibited nitroblue tetrazolium reduction of superoxide anion generated in a xanthine-xanthine oxidase system in solution. tcvSOD was chosen for further characterization because it was easier to produce. Recombinant tcvSOD …

Cell Type-Dependent Rna Recombination Frequency In The Japanese Encephalitis Virus, Wei-Wei Chiang, Chingkai Chuang, Mei Chao, Wei-June Chen

Plant Pathology Faculty Publications

Japanese encephalitis virus (JEV) is one of approximately 70 flaviviruses, frequently causing symptoms involving the central nervous system. Mutations of its genomic RNA frequently occur during viral replication, which is believed to be a force contributing to viral evolution. Nevertheless, accumulating evidences show that some JEV strains may have actually arisen from RNA recombination between genetically different populations of the virus. We have demonstrated that RNA recombination in JEV occurs unequally in different cell types. In the present study, viral RNA fragments transfected into as well as viral RNAs synthesized in mosquito cells were shown not to be stable, especially …

Management Of Root Knot Nematode (Meloidogyne Incognita ) In Indiana Soybeans, David Edgardo Perla Martinez

Open Access Theses

The aim of this project was to evaluate different strategies for management of Root Knot Nematode (RKN) on soybean and tomato in Indiana. Seed treatments were evaluated under field and greenhouse conditions, but no effect on RKN populations was observed. Soybean lines evaluated for resistance to RKN under greenhouse conditions showed that six lines may be resistant to RKN. Four different commercial mustard cover crops were evaluated for their bio-fumigant impact on RKN populations in the production of tomato. Euruca sativa, Cv. Nemat was a poor host of RKN. A positive impact on the vigor of the tomato plants followed …

Potential Susceptibility Of Canna Flaccida And Two Canna Hybrids To Five Species Of Phytophthora, Kristin Van Kampen

All Theses

The costs and need for clean water are increasing for greenhouse, nursery, and agricultural businesses. Runoff from irrigated agriculture and specialty crops also can take a toll on the surrounding environment, because irrigation runoff water can contain high amounts of nutrients, contaminants, and plant pathogens. To assuage the pollution contributed to runoff water and reduce the overall volume of water used, nurseries are starting to reuse irrigation runoff water. For this to be possible, the water first should be treated before reuse. Constructed wetlands are a biological treatment option that employs vegetation to collect, filter, and store runoff water. Some …

Pattern And Rate Of Decline Of A Population Of Carolina Hemlock (Tsuga Caroliniana Engelm.) In North Carolina, Foster Levy, Elaine S. Walker

ETSU Faculty Works

We monitored a population of Carolina Hemlocks in northwestern North Carolina for four years to examine the rate and pattern of decline in response to infestation by Adelges tsugae (Hemlock Woolly Adelgid). Our yearly census of hemlock condition and severity of the adelgid infestation included trees of all sizes. We estimated declines in condition as the portions of the leaf canopy that were lost. Initially, infestation occurred throughout the population but was severe in only a small cluster of individuals. Within 1 year, the area of severe infestation increased in size to encompass 48% of the population. In another region …

Coordinated And Distinct Functions Of Velvet Proteins In Fusarium Verticillioides, Nan Lan, Hanxing Zhang, Chengcheng Hu, Wenzhao Wang, Ana M. Calvo, Steven D. Harris, She Chen, Shaojie Li

Papers in Plant Pathology

Velvet-domain-containing proteins are broadly distributed within the fungal kingdom. In the corn pathogen Fusarium verticillioides, previous studies showed that the velvet protein F. verticillioides VE1 (FvVE1) is critical for morphological development, colony hydrophobicity, toxin production, and pathogenicity. In this study, tandem affinity purification of FvVE1 revealed that FvVE1 can form a complex with the velvet proteins F. verticillioides VelB (FvVelB) and FvVelC. Phenotypic characterization of gene knockout mutants showed that, as in the case of FvVE1, FvVelB regulated conidial size, hyphal hydrophobicity, fumonisin production, and oxidant resistance, while FvVelC was dispensable for these biological processes. Comparative transcriptional analysis of …

A Coordinated Effort To Manage Soybean Rust In North America: A Success Story In Soybean Disease Monitoring, E. J. Sikora, T. W. Allen, K. A. Wise, G. Bergstrom, C. A. Bradley, J. Bond, D. Brown-Rytlewski, M. Chilvers, J. Damicone, E. Dewolf, Ohio State University Dorrance, N. Dufault, P. Esker, T. R. Faske, L. Giesler, N. Goldberg, J. Golod, I. R. G. Gomez, C. Grau, A. Grybauskas, G. Franc, R. Hammerschmidt, G. L. Hartman, R. A. Henn, D. Hershman, C. Hollier, T. Isakeit, S. Isard, B. Jacobsen, D. Jardine, R. Kemerait, S. Koenning, M. Langham, D. Malvick, S. Markell, J. J. Marois, S. Monfort, D. S. Mueller, J. Mueller, R. Mulrooney, M. Newman, L. Osborne, G. B. Padgett, B. E. Ruden, J. Rupe, R. Schneider, H. Schwartz, G. Shaner, S. Singh, E. Stromberg, L. Sweets, A. Tenuta, S. Vaiciunas, X. B. Yang, H. Young-Kelly, J. Zidek

Papers in Plant Pathology

Existing crop monitoring programs determine the incidence and distribution of plant diseases and pathogens and assess the damage caused within a crop production region. These programs have traditionally used observed or predicted disease and pathogen data and environmental information to prescribe management practices that minimize crop loss (3,69). Monitoring programs are especially important for crops with broad geographic distribution or for diseases that can cause rapid and great economic losses. Successful monitoring programs have been developed for several plant diseases, including downy mildew of cucurbits, Fusarium head blight of wheat, potato late blight, and rusts of cereal crops (13,36,51,80).

Expression Of Chlorovirus Mt325 Aquaglyceroporin (Aqpv1) In Tobacco And Its Role In Mitigating Drought Stress, Saadia Bihmidine, Mingxia Cao, Ming Kang, Tala Awada, James L. Van Etten, David Dunigan, Thomas E. Clemente

James Van Etten Publications

Main conclusions A Chlorovirus aquaglyceroporin expressed in tobacco is localized to the plastid and plasma membranes. Transgenic events display improved response to water deficit. Necrosis in adult stage plants is observed.

Aquaglyceroporins are a subclass of the water channel aquaporin proteins (AQPs) that transport glycerol along with other small molecules transcellular in addition to water. In the studies communicated herein, we analyzed the expression of the aquaglyceroporin gene designated, aqpv1, from Chlorovirus MT325, in tobacco (Nicotiana tabacum), along with phenotypic changes induced by aqpv1 expression in planta. Interestingly, aqpv1 expression under control of either a constitutive or …

Surface-Soil Properties Of Alder Balds With Respect To Grassy And Rhododendron Balds On Roan Mountain, North Carolina—Tennessee, James T. Donaldson, Zachary C. Dinkins, Foster Levy, Arpita Nandi

ETSU Faculty Works

We analyzed soils in Alder Bald, Grassy Bald, and Rhododendron Bald communities on Roan Mountain to infer the influence of vegetation on soil and to help guide management strategies. In all vegetation types, soils were acid (pH = 4–5) sandy loams. We found vegetation-associated differences for organic content, cation exchange capacity, acidity, two plant macronutrients (K, Mg), and three cations (Fe, Na, Zn). We predicted that nitrogen compounds would be highest in the Alder Bald because Alnus viridis ssp. crispa (Green Alder) can harbor nitrogen-fixing bacteria. Organic content was highest at the alder-bald sites, ammonium was similar among vegetation types, …