Plant Pathology Commons^™

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 …

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 …

Noncanonical Role For The Host Vps4 Aaa+ Atpase Escrt Protein In The Formation Of Tomato Bushy Stunt Virus Replicase, Daniel Barajas, Isabel Fernández De Castro Martín, Judit Pogany, Cristina Risco, Peter D. Nagy

Plant Pathology Faculty Publications

Assembling of the membrane-bound viral replicase complexes (VRCs) consisting of viral- and host-encoded proteins is a key step during the replication of positive-stranded RNA viruses in the infected cells. Previous genome-wide screens with Tomato bushy stunt tombusvirus (TBSV) in a yeast model host have revealed the involvement of eleven cellular ESCRT (endosomal sorting complexes required for transport) proteins in viral replication. The ESCRT proteins are involved in endosomal sorting of cellular membrane proteins by forming multiprotein complexes, deforming membranes away from the cytosol and, ultimately, pinching off vesicles into the lumen of the endosomes. In this paper, we show an …

The Expanding Functions Of Cellular Helicases: The Tombusvirus Rna Replication Enhancer Co-Opts The Plant Eif4aiii-Like Atrh2 And The Ddx5-Like Atrh5 Dead-Box Rna Helicases To Promote Viral Asymmetric Rna Replication, Nikolay Kovalev, Peter D. Nagy

Plant Pathology Faculty Publications

Replication of plus-strand RNA viruses depends on recruited host factors that aid several critical steps during replication. Several of the co-opted host factors bind to the viral RNA, which plays multiple roles, including mRNA function, as an assembly platform for the viral replicase (VRC), template for RNA synthesis, and encapsidation during infection. It is likely that remodeling of the viral RNAs and RNA-protein complexes during the switch from one step to another requires RNA helicases. In this paper, we have discovered a second group of cellular RNA helicases, including the eIF4AIII-like yeast Fal1p and the DDX5-like Dbp3p and the orthologous …

Characterization Of Glomerella Strains Recovered From Anthracnose Lesions On Common Bean Plants In Brazil, Quélen L. Barcelos, Joyce M.A. Pinto, Lisa J. Vaillancourt, Elaine A. Souza

Plant Pathology Faculty Publications

Anthracnose caused by Colletotrichum lindemuthianum is an important disease of common bean, resulting in major economic losses worldwide. Genetic diversity of the C. lindemuthianum population contributes to its ability to adapt rapidly to new sources of host resistance. The origin of this diversity is unknown, but sexual recombination, via the Glomerella teleomorph, is one possibility. This study tested the hypothesis that Glomerella strains that are frequently recovered from bean anthracnose lesions represent the teleomorph of C. lindemuthianum. A large collection of Glomerella isolates could be separated into two groups based on phylogenetic analysis, morphology, and pathogenicity to beans. Both …

Inactivation Of The Host Lipin Gene Accelerates Rna Virus Replication Through Viral Exploitation Of The Expanded Endoplasmic Reticulum Membrane, Chingkai Chuang, Daniel Barajas, Jun Qin, Peter D. Nagy

Plant Pathology Faculty Publications

RNA viruses take advantage of cellular resources, such as membranes and lipids, to assemble viral replicase complexes (VRCs) that drive viral replication. The host lipins (phosphatidate phosphatases) are particularly interesting because these proteins play key roles in cellular decisions about membrane biogenesis versus lipid storage. Therefore, we examined the relationship between host lipins and tombusviruses, based on yeast model host. We show that deletion of PAH1 (phosphatidic acid phosphohydrolase), which is the single yeast homolog of the lipin gene family of phosphatidate phosphatases, whose inactivation is responsible for proliferation and expansion of the endoplasmic reticulum (ER) membrane, facilitates robust RNA …

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 …

Chemical Control Of Turfgrass Diseases 2014, Paul Vincelli, Gregg Munshaw

Agriculture and Natural Resources Publications

Turfgrasses under intensive management are often subject to outbreaks of infectious diseases. Diseases usually are most damaging when weather or cultural conditions favor the disease-causing agent but not plant growth and vigor. Cultural conditions that predispose turfgrass to diseases include close mowing, inadequate or excessive nitrogen fertility, light or frequent irrigation, excessive thatch, poor drainage, and shade.

Good turf management practices often greatly reduce the impact of disease by promoting healthy plants that are better able to resist infections. Even under good management, however, diseases sometimes cause excessive damage to highly managed turfgrasses. The proper use of fungicides in these …

Evaluation Of Pcr-Based Methods For Rapid, Accurate Detection And Monitoring Of Verticillium Dahliae In Woody Hosts By Real-Time Polymerase Chain Reaction, Baker Diwan Getheeth Aljawasim

Theses and Dissertations--Plant Pathology

Verticillium wilt, caused by Verticillium dahliae Kleb, is one of the most economically important diseases of woody hosts such as ash (Fraxinus spp.), sugar maple (Acer saccharum), and redbud (Cercis canadensis). The causal agent has a broad host range, including not only woody hosts but also important vegetable and field crops, and it is distributed worldwide. Diagnosis of V. dahliae in infected woody hosts is often based on the occurrence of vascular discoloration and time-consuming isolation. However, not all woody hosts exhibit vascular discoloration symptoms, and not all vascular discoloration symptoms are due to infection …

Construction Of A Sonchus Yellow Net Virus Minireplicon: A Step Toward Reverse Genetic Analysis Of Plant Negative-Strand Rna Viruses, Uma Ganesan, Jennifer N. Bragg, Min Deng, Sharon Marr, Mi Yeon Lee, Shasha Qian, Manling Shi, Justin Kappel, Cole Peters, Yeon Lee, Michael M. Goodin, Ralf G. Dietzgen, Zhenghe Li, Andrew O. Jackson

Plant Pathology Faculty Publications

Reverse genetic analyses of negative-strand RNA (NSR) viruses have provided enormous advances in our understanding of animal viruses over the past 20 years, but technical difficulties have hampered application to plant NSR viruses. To develop a reverse genetic approach for analysis of plant NSR viruses, we have engineered Sonchus yellow net nucleorhabdovirus (SYNV) minireplicon (MR) reporter cassettes for Agrobacterium tumefaciens expression in Nicotiana benthamiana leaves. Fluorescent reporter genes substituted for the SYNV N and P protein open reading frames (ORFs) exhibited intense single-cell foci throughout regions of infiltrated leaves expressing the SYNV MR derivatives and the SYNV nucleocapsid (N), phosphoprotein …

Tall Fescue Endophyte Effects On Tolerance To Water-Deficit Stress, Padmaja Nagabhyru, Randy D. Dinkins, Constance L. Wood, Charles W. Bacon, Christopher L. Schardl

Plant Pathology Faculty Publications

BACKGROUND: The endophytic fungus, Neotyphodium coenophialum, can enhance drought tolerance of its host grass, tall fescue. To investigate endophyte effects on plant responses to acute water deficit stress, we did comprehensive profiling of plant metabolite levels in both shoot and root tissues of genetically identical clone pairs of tall fescue with endophyte (E+) and without endophyte (E-) in response to direct water deficit stress. The E- clones were generated by treating E+ plants with fungicide and selectively propagating single tillers. In time course studies on the E+ and E- clones, water was withheld from 0 to 5 days, during which …

Currencies Of Mutualisms: Sources Of Alkaloid Genes In Vertically Transmitted Epichloae, Christopher L. Schardl, Carolyn A. Young, Juan Pan, Simona Florea, Johanna E. Takach, Daniel G. Panaccione, Mark L. Farman, Jennifer S. Webb, Jolanta Jaromczyk, Nikki D. Charlton, Padmaja Nagabhyru, Li Chen, Chong Shi, Adrian Leuchtmann

Plant Pathology Faculty Publications

The epichloae (Epichloë and Neotyphodium species), a monophyletic group of fungi in the family Clavicipitaceae, are systemic symbionts of cool-season grasses (Poaceae subfamily Poöideae). Most epichloae are vertically transmitted in seeds (endophytes), and most produce alkaloids that attack nervous systems of potential herbivores. These protective metabolites include ergot alkaloids and indole-diterpenes (tremorgens), which are active in vertebrate systems, and lolines and peramine, which are more specific against invertebrates. Several Epichloë species have been described which are sexual and capable of horizontal transmission, and most are vertically transmissible also. Asexual epichloae are mainly or exclusively vertically transmitted, and many are …

Three-Dimensional Structure Of Victorivirus Hvv190s Suggests Coat Proteins In Most Totiviruses Share A Conserved Core, Sarah E. Dunn, Hua Li, Giovanni Cardone, Max L. Nibert, Said A. Ghabrial, Timothy S. Baker

Plant Pathology Faculty Publications

Double-stranded (ds)RNA fungal viruses are currently assigned to six different families. Those from the family Totiviridae are characterized by nonsegmented genomes and single-layer capsids, 300-450 Å in diameter. Helminthosporium victoriae virus 190S (HvV190S), prototype of recently recognized genus Victorivirus, infects the filamentous fungus Helminthosporium victoriae (telomorph: Cochliobolus victoriae), which is the causal agent of Victoria blight of oats. The HvV190S genome is 5179 bp long and encompasses two large, slightly overlapping open reading frames that encode the coat protein (CP, 772 aa) and the RNA-dependent RNA polymerase (RdRp, 835 aa). To our present knowledge, victoriviruses uniquely express their RdRps via …

Plant-Symbiotic Fungi As Chemical Engineers: Multi-Genome Analysis Of The Clavicipitaceae Reveals Dynamics Of Alkaloid Loci, Christopher L. Schardl, Carolyn A. Young, Uljana Hesse, Stefan G. Amyotte, Kalina Andreeva, Patrick J. Calie, Damien J. Fleetwood, David C. Haws, Neil Moore, Birgitt Oeser, Daniel G. Panaccione, Kathryn K. Schweri, Christine R. Voisey, Mark L. Farman, Jerzy W. Jaromczyk, Bruce A. Roe, Donal M. O'Sullivan, Barry Scott, Paul Tudzynski, Zhiqiang An, Elissaveta G. Arnaoudova, Charles T. Bullock, Nikki D. Charlton, Li Chen, Murray Cox, Randy D. Dinkins, Simona Florea, Anthony E. Glenn, Anna Gordon, Ulrich Güldener, Daniel R. Harris, Walter Hollin, Jolanta Jaromczyk, Richard D. Johnson, Anar K. Khan, Eckhard Leistner, Adrian Leuchtmann, Chunjie Li, Jinge Liu, Jinze Liu, Miao Liu, Wade Mace, Caroline Machado, Padmaja Nagabhyru, Juan Pan, Jan Schmid, Koya Sugawara, Ulrike Steiner, Johanna E. Takach, Eiji Tanaka, Jennifer S. Webb, Ella V. Wilson, Jennifer L. Wiseman, Ruriko Yoshida, Zheng Zeng

Plant Pathology Faculty Publications

The fungal family Clavicipitaceae includes plant symbionts and parasites that produce several psychoactive and bioprotective alkaloids. The family includes grass symbionts in the epichloae clade (Epichloë and Neotyphodium species), which are extraordinarily diverse both in their host interactions and in their alkaloid profiles. Epichloae produce alkaloids of four distinct classes, all of which deter insects, and some-including the infamous ergot alkaloids-have potent effects on mammals. The exceptional chemotypic diversity of the epichloae may relate to their broad range of host interactions, whereby some are pathogenic and contagious, others are mutualistic and vertically transmitted (seed-borne), and still others vary in pathogenic …

Mites In The Promoters Of Effector Genes Allow Prediction Of Novel Virulence Genes In Fusarium Oxysporum, Sarah M. Schmidt, Petra M. Houterman, Ines Schreiver, Lisong Ma, Stefan G. Amyotte, Biju Chellappan, Sjef Boeren, Frank L. W. Takken, Martijn Rep

Plant Pathology Faculty Publications

BACKGROUND: The plant-pathogenic fungus Fusarium oxysporum f.sp.lycopersici (Fol) has accessory, lineage-specific (LS) chromosomes that can be transferred horizontally between strains. A single LS chromosome in the Fol4287 reference strain harbors all known Fol effector genes. Transfer of this pathogenicity chromosome confers virulence to a previously non-pathogenic recipient strain. We hypothesize that expression and evolution of effector genes is influenced by their genomic context.

RESULTS: To gain a better understanding of the genomic context of the effector genes, we manually curated the annotated genes on the pathogenicity chromosome and identified and classified transposable elements. Both retro- and DNA transposons are present …

Alternative Methods Of Control For Phytophthora Nicotianae Of Tobacco, Anna M. Holdcroft

Theses and Dissertations--Plant Pathology

Kentucky is the nation’s leading producer of burley tobacco and the crop’s most economically important disease is black shank, caused by Phytophthora nicotianae (Pn). Current management is effective, however, problems with expense and pathogen persistence are issues. Two alternative methods for control of Pn were examined: biofumigation and soil application of an organic, yeast fermentation‐derived product (Soil‐Set). Field studies in 2009 and 2010 found no effect on populations of fungi, disease severity of Pn, and yield between mustard‐ and wheat‐amended plots. Experiments in the greenhouse suggested that survival of Pn was impacted by biomass rather than biofumigation. Biofumigation is not …

Cellular And Molecular Aspects Of The Interaction Betwen Maize And The Anthracnose Pathogen Colletotrichum Graminicola, Maria F. Torres

Theses and Dissertations--Plant Pathology

Maize anthracnose, caused by the fungus Colletotrichum graminicola, is an economically important species contributing to major yield losses. C. graminicola is a hemibiotroph; initially it invades its host while it is alive, and then it switches to destructive necrotrophic growth and the host is killed. Establishment of compatible interactions by biotrophic pathogens is usually associated with suppression of host defenses and cell death, while necrotrophic pathogens typically secrete phytotoxic compounds and induce cell death. To understand the relationship of hemibiotrophy in C. graminicola to biotrophy and necrotrophy, I compared a compatible and an incompatible interaction, utilizing a non-pathogenic …

Overexpression/Silencing Of Selected Soybean Genes Alters Resistance To Pathogens, Mohamed H. El-Habbak

Theses and Dissertations--Plant Pathology

Plant diseases remain a major obstruction to meeting the world’s increased demand for soybean oil and protein. Reducing the losses caused by diseases in order to improve crop production is a high priority for agricultural research. The need for novel strategies for plant disease control cannot be overstated. In the present study, selected defense-related genes were silenced and/or overexpressed in soybean using a virus-based vector and the resultant plants were tested for their responses to pathogens. The first part of the study focused on Rps1k (Resistance to Phytophthora sojae) gene. The two conserved domains encoding ‘P-Loop NTPase’ and ‘PLN03210’ …

Control Of Erwinia Tracheiphila In Cucumis Melo, John R. Caudle

Theses and Dissertations--Plant and Soil Sciences

Currently there is no control of bacterial wilt disease, Erwinia tracheiphila, in susceptible cucurbit crops, once infection of the plant occurs. Conventional and organic production systems rely on insecticide applications to kill the vectors, striped and spotted cucumber beetles, Acalymma vittatum and Diabrotica undecimpunctata, respectively, prior to transmission of the pathogen which indirectly controls the disease to some extent. Physical barriers such as row covers are used to exclude the vectors from plants prior to flowering; however, pollination requirements expose plants to potential infection. Experimental field plots were developed to test various enhanced organic production systems in an …

Discovery Of Novel Dsrna Viral Sequences By In Silico Cloning And Implications For Viral Diversity, Host Range And Evolution, Huiquan Liu, Yanping Fu, Jiatao Xie, Jiasen Cheng, Said A. Ghabrial, Guoqing Li, Xianhong Yi, Daohong Jiang

Plant Pathology Faculty Publications

Genome sequence of viruses can contribute greatly to the study of viral evolution, diversity and the interaction between viruses and hosts. Traditional molecular cloning methods for obtaining RNA viral genomes are time-consuming and often difficult because many viruses occur in extremely low titers. DsRNA viruses in the families, Partitiviridae, Totiviridae, Endornaviridae, Chrysoviridae, and other related unclassified dsRNA viruses are generally associated with symptomless or persistent infections of their hosts. These characteristics indicate that samples or materials derived from eukaryotic organisms used to construct cDNA libraries and EST sequencing might carry these viruses, which were not easily detected by the researchers. …

Plants Having An Enhanced Resistance To Necrotrophic Pathogens And Method Of Making Same, Pradeep Kachroo, Aardra Kachroo

Plant Pathology Faculty Patents

A method for enhancing resistance to necrotrophic and/or hemibiotrophic pathogens by overexpressing glycerol-3-phosphate dehydrogenase using an expression vector in a plant species. For example, the present method can be used to enhance resistance to C. higginsianum by overexpressing glycerol-3-phosphate dehydrogenase in a plant such as Arabidopsis plant, using an expression vector in a plant.

Evolutionary Genomics Of Mycovirus-Related Dsrna Viruses Reveals Cross-Family Horizontal Gene Transfer And Evolution Of Diverse Viral Lineages, Huiquan Liu, Yanping Fu, Jiatao Xie, Jiasen Cheng, Said A. Ghabrial, Guoqing Li, Youliang Peng, Xianhong Yi, Daohong Jiang

Plant Pathology Faculty Publications

BACKGROUND: Double-stranded (ds) RNA fungal viruses are typically isometric single-shelled particles that are classified into three families, Totiviridae, Partitiviridae and Chrysoviridae, the members of which possess monopartite, bipartite and quadripartite genomes, respectively. Recent findings revealed that mycovirus-related dsRNA viruses are more diverse than previously recognized. Although an increasing number of viral complete genomic sequences have become available, the evolution of these diverse dsRNA viruses remains to be clarified. This is particularly so since there is little evidence for horizontal gene transfer (HGT) among dsRNA viruses.

RESULTS: In this study, we report the molecular properties of two novel dsRNA mycoviruses that …

A Co-Opted Dead-Box Rna Helicase Enhances Tombusvirus Plus-Strand Synthesis, Nikolay Kovalev, Judit Pogany, Peter D. Nagy

Plant Pathology Faculty Publications

Replication of plus-strand RNA viruses depends on recruited host factors that aid several critical steps during replication. In this paper, we show that an essential translation factor, Ded1p DEAD-box RNA helicase of yeast, directly affects replication of Tomato bushy stunt virus (TBSV). To separate the role of Ded1p in viral protein translation from its putative replication function, we utilized a cell-free TBSV replication assay and recombinant Ded1p. The in vitro data show that Ded1p plays a role in enhancing plus-strand synthesis by the viral replicase. We also find that Ded1p is a component of the tombusvirus replicase complex and Ded1p …

The Tpr Domain In The Host Cyp40-Like Cyclophilin Binds To The Viral Replication Protein And Inhibits The Assembly Of The Tombusviral Replicase, Jing-Yi Lin, Venugopal Mendu, Judit Pogany, Jun Qin, Peter D. Nagy

Plant Pathology Faculty Publications

Replication of plus-stranded RNA viruses is greatly affected by numerous host-coded proteins acting either as susceptibility or resistance factors. Previous genome-wide screens and global proteomics approaches with Tomato bushy stunt tombusvirus (TBSV) in a yeast model host revealed the involvement of cyclophilins, which are a large family of host prolyl isomerases, in TBSV replication. In this paper, we identified those members of the large cyclophilin family that interacted with the viral replication proteins and inhibited TBSV replication. Further characterization of the most effective cyclophilin, the Cyp40-like Cpr7p, revealed that it strongly inhibits many steps during TBSV replication in a cell-free …

Molecular And Biochemical Characterization Of Oleate- And Glycerol-3-Phosphate-Regulated Signaling In Plants, Mihir Kumar Mandal

Theses and Dissertations--Plant Pathology

Oleic acid (18:1), a monounsaturated fatty acid (FA), is synthesized upon desaturation of stearic acid (18:0) and this reaction is catalyzed by the plastidal enzyme stearoyl-acyl carrier protein-desaturase (SACPD). A mutation in the SSI2/FAB2 encoded SACPD lowers 18:1 levels, which correlates with induction of various resistance (R) genes and increased resistance to pathogens. Genetic and molecular studies have identified several suppressors of ssi2 which restore altered defense signaling either by normalizing 18:1 levels or by affecting function(s) of a downstream component. Characterization of one such ssi2 suppressor mutant showed that it is required downstream of low 18:1-mediated constitutive …

Glycerolipids And The Plant Cuticle Contribute To Plant Immunity, Qing-Ming Gao

Theses and Dissertations--Plant Pathology

The conserved metabolites, oleic acid (18:1), a major monounsaturated fatty acid (FA), and glycerol-3-phosphate (G3P) are obligatory precursors of glycerolipid biosynthesis in plants. In Arabidopsis, the SSI2-encoded SACPD is the major isoform that contributes to 18:1 biosynthesis. Signaling induced upon reduction in oleic acid (18:1) levels not only upregulates salicylic acid (SA)-mediated responses but also inhibits jasmonic acid (JA)- inducible defenses. I examined the transcription profile of ssi2 plants and identified two transcription factors, WRKY50 and WRKY51. Although the ssi2 wrky50 and ssi2 wrky51 plants were constitutively upregulated in SA-derived signaling, they were restored in JAdependent defense signaling. Not only …

Glycerol-3-Phosphate Is A Novel Regulator Of Basal And Induced Defense Signaling In Plants, Bidisha Chanda

Theses and Dissertations--Plant Pathology

Plants use several strategies to defend themselves against microbial pathogens. These include basal resistance, which is induced in response to pathogen encoded effector proteins, and resistance (R) protein-mediated resistance that is activated upon direct or indirect recognition of pathogen encoded avirulence protein(s). The activation of Rmediated signaling is often associated with generation of a signal, which, upon its translocation to the distal uninfected parts, confers broad-spectrum immunity against related or unrelated pathogens. This phenomenon known as systemic acquired resistance (SAR) is one of the well-established forms of induced defense response. However, the molecular mechanism underlying SAR remains largely unknown. Induction …

Synergistic Roles Of Eukaryotic Translation Elongation Factors 1bγ And 1a In Stimulation Of Tombusvirus Minus-Strand Synthesis, Zsuzsanna Sasvari, Lara Izotova, Terri Goss Kinzy, Peter D. Nagy

Plant Pathology Faculty Publications

Host factors are recruited into viral replicase complexes to aid replication of plus-strand RNA viruses. In this paper, we show that deletion of eukaryotic translation elongation factor 1Bgamma (eEF1Bγ) reduces Tomato bushy stunt virus (TBSV) replication in yeast host. Also, knock down of eEF1Bγ level in plant host decreases TBSV accumulation. eEF1Bγ binds to the viral RNA and is one of the resident host proteins in the tombusvirus replicase complex. Additional in vitro assays with whole cell extracts prepared from yeast strains lacking eEF1Bγ demonstrated its role in minus-strand synthesis by opening of the structured 3' end of the viral …