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Full-Text Articles in Organisms

How Megadrought Causes Extensive Mortality In A Deep-Rooted Shrub Species Normally Resistant To Drought-Induced Dieback: The Role Of A Biotic Mortality Agent, Natalie M. Aguirre, Marissa E. Ochoa, Helen I. Holmlund, Gabriella N. Palmeri, Emily R. Lancaster, Gina S. Gilderman, Shaquetta R. Taylor, Kaitlyn E. Sauer, Adriana J. Borges, Avery N.D. Lamb, Sarah B. Jacques, Frank W. Ewers, Stephen D. Davis Nov 2023

How Megadrought Causes Extensive Mortality In A Deep-Rooted Shrub Species Normally Resistant To Drought-Induced Dieback: The Role Of A Biotic Mortality Agent, Natalie M. Aguirre, Marissa E. Ochoa, Helen I. Holmlund, Gabriella N. Palmeri, Emily R. Lancaster, Gina S. Gilderman, Shaquetta R. Taylor, Kaitlyn E. Sauer, Adriana J. Borges, Avery N.D. Lamb, Sarah B. Jacques, Frank W. Ewers, Stephen D. Davis

School of Medicine Faculty Publications

Southern California experienced unprecedented megadrought between 2012 and 2018. During this time, Malosma laurina, a chaparral species normally resilient to single-year intense drought, developed extensive mortality exceeding 60% throughout low-elevation coastal populations of the Santa Monica Mountains. We assessed the physiological mechanisms by which the advent of megadrought predisposed M. laurina to extensive shoot dieback and whole-plant death. We found that hydraulic conductance of stem xylem (Ks, native) was reduced seven to 11-fold in dieback adult and resprout branches, respectively. Staining of stem xylem vessels revealed that dieback plants experienced 68% solid-blockage, explaining the reduction in water transport. Following Koch's …


Integration Of Medicinal Fungi Into The Heber W. Youngken Jr. Medicinal Garden, Anthony Makashov May 2022

Integration Of Medicinal Fungi Into The Heber W. Youngken Jr. Medicinal Garden, Anthony Makashov

Senior Honors Projects

The Heber W. Youngken Jr. Medicinal Garden is a one-of-a-kind resource that houses close to 300 medicinal plants and is filled to the brim with educational opportunities. For the College of Pharmacy, this garden has been the centerpiece of many classes taught here at the University of Rhode Island and has roots as a physical teaching space. While the garden contains a plethora of plant species, medicinal fungi have yet to have been included in the garden, despite their relevance as both sources of pharmaceutical drug discovery and as natural products with inherent physiological benefits themselves. The purpose of my …


Trigonella Foenum-Graecum Methanolic Extract On Isolated Smooth Muscles And Acetylcholinesterase Enzyme: An In Vitro And Mechanistic In Silico Investigation, Muhammad Nabeel Ghayur, Mohnad Abdalla, Asaad Khalid, Saeed Ahmad, Anwar Gilani Apr 2022

Trigonella Foenum-Graecum Methanolic Extract On Isolated Smooth Muscles And Acetylcholinesterase Enzyme: An In Vitro And Mechanistic In Silico Investigation, Muhammad Nabeel Ghayur, Mohnad Abdalla, Asaad Khalid, Saeed Ahmad, Anwar Gilani

Department of Biological & Biomedical Sciences

Results: When tested on the baseline of isolated tissues, Tfg.Cr was devoid of any activity (stimulant or relaxant) till 10 mg/ml. This is an interesting finding, keeping in mind that the fenugreek seeds are used to alleviate constipation and diarrhoea. When Tfg.Cr was tried for any potential AChE inhibitory activity, it did show an inhibitory effect in increasing concentrations (47-380 μg/ml). This inhibitory effect was comparable to the effect produced by a standard AChE inhibitor physostigmine. One of the known fenugreek constituents, diosgenin, was also tested, and it also showed an AChE inhibitory effect in a concentration-dependent manner (11-190 …


Smrt Sequencing Of Paramecium Bursaria Chlorella Virus-1 Reveals Diverse Methylation Stability In Adenines Targeted By Restriction Modification Systems, Samantha R. Coy, Eric R. Gann, Spiridon E. Papoulis, Michael E. Holder, Nadim J. Ajami, Joseph F. Petrosino, Erik R. Zinser, James L. Van Etten, Steven W. Wilhelm May 2020

Smrt Sequencing Of Paramecium Bursaria Chlorella Virus-1 Reveals Diverse Methylation Stability In Adenines Targeted By Restriction Modification Systems, Samantha R. Coy, Eric R. Gann, Spiridon E. Papoulis, Michael E. Holder, Nadim J. Ajami, Joseph F. Petrosino, Erik R. Zinser, James L. Van Etten, Steven W. Wilhelm

James Van Etten Publications

Chloroviruses (family Phycodnaviridae) infect eukaryotic, freshwater, unicellular green algae. A unique feature of these viruses is an abundance of DNA methyltransferases, with isolates dedicating up to 4.5% of their protein coding potential to these genes. This diversity highlights just one of the long-standing values of the chlorovirus model system; where group-wide epigenomic characterization might begin to elucidate the function(s) of DNA methylation in large dsDNA viruses. We characterized DNA modifications in the prototype chlorovirus, PBCV-1, using single-molecule real time (SMRT) sequencing (aka PacBio). Results were compared to total available sites predicted in silico based on DNA sequence alone. SMRT-software detected …


Reporting Charcoal Rot In Chia And Developing A Susceptibility Assay, Reis M. Misaka, Hagop S. Atamian Dr., Julien Besnard Dr. May 2019

Reporting Charcoal Rot In Chia And Developing A Susceptibility Assay, Reis M. Misaka, Hagop S. Atamian Dr., Julien Besnard Dr.

Student Scholar Symposium Abstracts and Posters

Chia (Salvia Hispanica) cross breeds were planted in the summer of 2018 with the intent of selective breeding for agricultural benefit. Preexisting pathogens in the soil caused 40-50% fatality of adult plants. This was surprising due to the precursory knowledge that chia has antibiotic and antifungal oils (Elshafie et. al. 2018); chia was only recently documented to be susceptible to Fusarium wilt (Fusarium oxysporum). The primary pathogen responsible was identified as Macrophomina phaseolina (aka charcoal rot); a widespread soilborne pathogen which has multiple commercial hosts (Su et. al. 2001).

M. phaesolina on wheat seed vector where used as …


Chloroviruses Lure Hosts Through Long-Distance Chemical Signaling, David Dunigan, Maitham Ahmed Al-Sammak, Zeina Al-Ameeli, Irina Agarkova, John Delong, James L. Van Etten Jan 2019

Chloroviruses Lure Hosts Through Long-Distance Chemical Signaling, David Dunigan, Maitham Ahmed Al-Sammak, Zeina Al-Ameeli, Irina Agarkova, John Delong, James L. Van Etten

James Van Etten Publications

Chloroviruses exist in aquatic systems around the planet where they infect certain eukaryotic green algae that are mutualistic endosymbionts in a variety of protists and metazoans. Natural chlorovirus populations are seasonally dynamic but the precise temporal changes in these populations and the mechanisms that underlie them have, heretofore, been unclear. We recently reported the novel concept that predator/prey-mediated virus activation regulates chlorovirus population dynamics, and in the current manuscript demonstrate virus packaged chemotactic modulation of prey behavior.

Viruses have not previously been reported to act as chemotactic/chemo-attractive agents. Rather, viruses as extracellular entities are generally viewed as non-metabolically active spore-like …


The N-Glycan Structures Of The Antigenic Variants Of Chlorovirus Pbcv-1 Major Capsid Protein Help To Identify The Virus-Encoded Glycosyltransferases, Immacolata Speciale, Garry A. Duncan, Luca Unione, Irina Agarkova, Domenico Garozzo, Jesus Jimenez-Barbero, Sicheng Lin, Todd L. Lowary, Antonio Molinaro, Eric Noel, Maria Elena Laugieri, Michela Tonetti, James L. Van Etten, Cristina De Castro Jan 2019

The N-Glycan Structures Of The Antigenic Variants Of Chlorovirus Pbcv-1 Major Capsid Protein Help To Identify The Virus-Encoded Glycosyltransferases, Immacolata Speciale, Garry A. Duncan, Luca Unione, Irina Agarkova, Domenico Garozzo, Jesus Jimenez-Barbero, Sicheng Lin, Todd L. Lowary, Antonio Molinaro, Eric Noel, Maria Elena Laugieri, Michela Tonetti, James L. Van Etten, Cristina De Castro

James Van Etten Publications

The chlorovirus Paramecium bursaria chlorella virus 1 (PBCV-1) is a large dsDNA virus that infects the microalga Chlorella variabilis NC64A. Unlike most other viruses, PBCV-1 encodes most, if not all, of the machinery required to glycosylate its major capsid protein (MCP). The structures of the four N-linked glycans from the PBCV-1 MCP consist of nonasaccharides, and similar glycans are not found elsewhere in the three domains of life. Here, we identified the roles of three virus-encoded glycosyltransferases (GTs) that have four distinct GT activities in glycan synthesis. Two of the three GTs were previously annotated as GTs but the third …


Repeat Elements Organise 3d Genome Structure And Mediate Transcription In The Filamentous Fungus Epichloë Festucae, David J. Winter, Austen R. D. Ganley, Carolyn A. Young, Ivan Liachko, Christopher L. Schardl, Pierre-Yves Dupont, Daniel Berry, Arvina Ram, Barry Scott, Murray P. Cox Oct 2018

Repeat Elements Organise 3d Genome Structure And Mediate Transcription In The Filamentous Fungus Epichloë Festucae, David J. Winter, Austen R. D. Ganley, Carolyn A. Young, Ivan Liachko, Christopher L. Schardl, Pierre-Yves Dupont, Daniel Berry, Arvina Ram, Barry Scott, Murray P. Cox

Plant Pathology Faculty Publications

Structural features of genomes, including the three-dimensional arrangement of DNA in the nucleus, are increasingly seen as key contributors to the regulation of gene expression. However, studies on how genome structure and nuclear organisation influence transcription have so far been limited to a handful of model species. This narrow focus limits our ability to draw general conclusions about the ways in which three-dimensional structures are encoded, and to integrate information from three-dimensional data to address a broader gamut of biological questions. Here, we generate a complete and gapless genome sequence for the filamentous fungus, Epichloë festucae. We use Hi-C …


Iac Gene Expression In The Indole-3-Acetic Acid-Degrading Soil Bacterium Enterobacter Soli Lf7, Isaac V. Greenhut, Beryl L. Slezak, Johan H. J. Leveau Oct 2018

Iac Gene Expression In The Indole-3-Acetic Acid-Degrading Soil Bacterium Enterobacter Soli Lf7, Isaac V. Greenhut, Beryl L. Slezak, Johan H. J. Leveau

Plant and Soil Sciences Faculty Publications

We show for soil bacterium Enterobacter soli LF7 that the possession of an indole-3-acetic acid catabolic (iac) gene cluster is causatively linked to the ability to utilize the plant hormone indole-3-acetic acid (IAA) as a carbon and energy source. Genome-wide transcriptional profiling by mRNA sequencing revealed that these iac genes, chromosomally arranged as iacHABICDEFG and coding for the transformation of IAA to catechol, were the most highly induced (>29-fold) among the relatively few (iac cluster were genes for a major facilitator superfamily protein (mfs) and enzymes of the β-ketoadipate pathway (pcaIJD-catBCA), which channels …


Capsid Structure Of Dsrna Fungal Viruses, Daniel Luque, Carlos P. Mata, Nobuhiro Suzuki, Said A. Ghabrial, José R. Castón Sep 2018

Capsid Structure Of Dsrna Fungal Viruses, Daniel Luque, Carlos P. Mata, Nobuhiro Suzuki, Said A. Ghabrial, José R. Castón

Plant Pathology Faculty Publications

Most fungal, double-stranded (ds) RNA viruses lack an extracellular life cycle stage and are transmitted by cytoplasmic interchange. dsRNA mycovirus capsids are based on a 120-subunit T = 1 capsid, with a dimer as the asymmetric unit. These capsids, which remain structurally undisturbed throughout the viral cycle, nevertheless, are dynamic particles involved in the organization of the viral genome and the viral polymerase necessary for RNA synthesis. The atomic structure of the T = 1 capsids of four mycoviruses was resolved: the L-A virus of Saccharomyces cerevisiae (ScV-L-A), Penicillium chrysogenum virus (PcV), Penicillium stoloniferum virus F (PsV-F), and Rosellinia necatrix …


Deletion Of Endo-Β-1,4-Xylanase Vmxyl1 Impacts The Virulence Of Valsa Mali In Apple Tree, Chunlei Yu, Ting Li, Xiangpeng Shi, Muhammad Saleem, Baohua Li, Wenxing Liang, Caixia Wang May 2018

Deletion Of Endo-Β-1,4-Xylanase Vmxyl1 Impacts The Virulence Of Valsa Mali In Apple Tree, Chunlei Yu, Ting Li, Xiangpeng Shi, Muhammad Saleem, Baohua Li, Wenxing Liang, Caixia Wang

Plant and Soil Sciences Faculty Publications

Valsa mali, a parasitic fungus, is a destructive pathogen of apple tree that causes heavy economic losses in China. The pathogen secretes various cell wall-degrading enzymes (CWDEs) that degrade plant cell-wall components, and thus facilitate its entry into host cells. Therefore, functional analysis of the genes encoding CWDEs is necessary to understand virulence of V. mali toward apple tree. Here, we identified and cloned an endo-β-1,4-xylanase gene, VmXyl1 in V. mali. The full-length cDNA of VmXyl1 is 1626 bp containing 5′- and 3′-non-coding regions, as well an open reading frame of 1320 bp that encodes a protein with …


Genetic And Molecular Mechanisms Underlying Symbiotic Specificity In Legume-Rhizobium Interactions, Qi Wang, Jinge Liu, Hongyan Zhu Mar 2018

Genetic And Molecular Mechanisms Underlying Symbiotic Specificity In Legume-Rhizobium Interactions, Qi Wang, Jinge Liu, Hongyan Zhu

Plant and Soil Sciences Faculty Publications

Legumes are able to form a symbiotic relationship with nitrogen-fixing soil bacteria called rhizobia. The result of this symbiosis is to form nodules on the plant root, within which the bacteria can convert atmospheric nitrogen into ammonia that can be used by the plant. Establishment of a successful symbiosis requires the two symbiotic partners to be compatible with each other throughout the process of symbiotic development. However, incompatibility frequently occurs, such that a bacterial strain is unable to nodulate a particular host plant or forms nodules that are incapable of fixing nitrogen. Genetic and molecular mechanisms that regulate symbiotic specificity …


Recombinant Promoter (Muascsv8cp) Driven Totiviral Killer Protein 4 (Kp4) Imparts Resistance Against Fungal Pathogens In Transgenic Tobacco, Debasish Deb, Ankita Shrestha, Indu B. Maiti, Nrisingha Dey Mar 2018

Recombinant Promoter (Muascsv8cp) Driven Totiviral Killer Protein 4 (Kp4) Imparts Resistance Against Fungal Pathogens In Transgenic Tobacco, Debasish Deb, Ankita Shrestha, Indu B. Maiti, Nrisingha Dey

Kentucky Tobacco Research and Development Center Faculty Publications

Development of disease-resistant plant varieties achieved by engineering anti-microbial transgenes under the control of strong promoters can suffice the inhibition of pathogen growth and simultaneously ensure enhanced crop production. For evaluating the prospect of such strong promoters, we comprehensively characterized the full-length transcript promoter of Cassava Vein Mosaic Virus (CsVMV; -565 to +166) and identified CsVMV8 (-215 to +166) as the highest expressing fragment in both transient and transgenic assays. Further, we designed a new chimeric promoter ‘MUASCsV8CP’ through inter-molecular hybridization among the upstream activation sequence (UAS) of Mirabilis Mosaic Virus (MMV; -297 to -38) and CsVMV8, as the core …


Phaeophleospora Vochysiae Savi & Glienke Sp. Nov. Isolated From Vochysia Divergens Found In The Pantanal, Brazil, Produces Bioactive Secondary Metabolites, Daiani C. Savi, Khaled A. Shaaban, Francielly M. W. Gos, Larissa V. Ponomareva, Jon S. Thorson, Chirlei Glienke, Jürgen Rohr Feb 2018

Phaeophleospora Vochysiae Savi & Glienke Sp. Nov. Isolated From Vochysia Divergens Found In The Pantanal, Brazil, Produces Bioactive Secondary Metabolites, Daiani C. Savi, Khaled A. Shaaban, Francielly M. W. Gos, Larissa V. Ponomareva, Jon S. Thorson, Chirlei Glienke, Jürgen Rohr

Pharmaceutical Sciences Faculty Publications

Microorganisms associated with plants are highly diverse and can produce a large number of secondary metabolites, with antimicrobial, anti-parasitic and cytotoxic activities. We are particularly interested in exploring endophytes from medicinal plants found in the Pantanal, a unique and widely unexplored wetland in Brazil. In a bio-prospecting study, strains LGMF1213 and LGMF1215 were isolated as endophytes from Vochysia divergens, and by morphological and molecular phylogenetic analyses were characterized as Phaeophleospora vochysiae sp. nov. The chemical assessment of this species reveals three major compounds with high biological activity, cercoscosporin (1), isocercosporin (2) and the new compound 3-(sec-butyl)-6-ethyl-4,5-dihydroxy-2-methoxy-6-methylcyclohex-2-enone (3). …


Genes For Membrane Transport Proteins: Not So Rare In Viruses, Timo Greiner, Anna Moroni, James L. Van Etten, Gerhard Thiel Jan 2018

Genes For Membrane Transport Proteins: Not So Rare In Viruses, Timo Greiner, Anna Moroni, James L. Van Etten, Gerhard Thiel

James Van Etten Publications

Some viruses have genes encoding proteins with membrane transport functions. It is unknown if these types of proteins are rare or are common in viruses. In particular, the evolutionary origin of some of the viral genes is obscure, where other viral proteins have homologs in prokaryotic and eukaryotic organisms. We searched virus genomes in databases looking for transmembrane proteins with possible transport function. This effort led to the detection of 18 different types of putative membrane transport proteins indicating that they are not a rarity in viral genomes. The most abundant proteins are K+ channels. Their predicted structures vary between …


Size-Dependent Catalysis Of Chlorovirus Population Growth By A Messy Feeding Predator, John Delong, Zeina Al-Ameeli, Shelby Lyon, James L. Van Etten, David Dunigan Jan 2018

Size-Dependent Catalysis Of Chlorovirus Population Growth By A Messy Feeding Predator, John Delong, Zeina Al-Ameeli, Shelby Lyon, James L. Van Etten, David Dunigan

James Van Etten Publications

Many chloroviruses replicate in endosymbiotic zoochlorellae that are protected from infection by their symbiotic host. To reach the high virus concentrations that often occur in natural systems, a mechanism is needed to release zoochlorellae from their hosts. We demonstrate that the ciliate predator Didinium nasutum foraging on zoochlorellae-bearing Paramecium bursaria can release live zoochlorellae from the ruptured prey cell that can then be infected by chloroviruses. The catalysis process is very effective, yielding roughly 95% of the theoretical infectious virus yield as determined by sonication of P. bursaria. Chlorovirus activation is more effective with smaller Didinia, as larger …


Biophysical Approaches To Solve The Structures Of The Complex Glycan Shield Of Chloroviruses, Cristina De Castro, Garry Duncan, Domenico Garozzo, Antonio Molinaro, Luisa Sturiale, Michela Tonetti, James L. Van Etten Jan 2018

Biophysical Approaches To Solve The Structures Of The Complex Glycan Shield Of Chloroviruses, Cristina De Castro, Garry Duncan, Domenico Garozzo, Antonio Molinaro, Luisa Sturiale, Michela Tonetti, James L. Van Etten

James Van Etten Publications

The capsid of Paramecium bursaria chlorella virus (PBCV-1) contains a heavily glycosylated major capsid protein, Vp54. The capsid protein contains four glycans, each N-linked to Asn. The glycan structures are unusual in many aspects: (1) they are attached by a β-glucose linkage, which is rare in nature; (2) they are highly branched and consist of 8–10 neutral monosaccharides; (3) all four glycoforms contain a dimethylated rhamnose as the capping residue of the main chain, a hyper-branched fucose residue and two rhamnose residues ''with opposite absolute configurations; (4) the four glycoforms differ by the nonstoichiometric presence of two monosaccharides, l-arabinose and …


Acquisition Of Functions On The Outer Capsid Surface During Evolution Of Double-Stranded Rna Fungal Viruses, Carlos P. Mata, Daniel Luque, Josué Gómez-Blanco, Javier M. Rodríguez, José M. González, Nobuhiro Suzuki, Said A. Ghabrial, José L. Carrascosa, Benes L. Trus, José R. Castón Dec 2017

Acquisition Of Functions On The Outer Capsid Surface During Evolution Of Double-Stranded Rna Fungal Viruses, Carlos P. Mata, Daniel Luque, Josué Gómez-Blanco, Javier M. Rodríguez, José M. González, Nobuhiro Suzuki, Said A. Ghabrial, José L. Carrascosa, Benes L. Trus, José R. Castón

Plant Pathology Faculty Publications

Unlike their counterparts in bacterial and higher eukaryotic hosts, most fungal viruses are transmitted intracellularly and lack an extracellular phase. Here we determined the cryo-EM structure at 3.7 Å resolution of Rosellinia necatrix quadrivirus 1 (RnQV1), a fungal double-stranded (ds)RNA virus. RnQV1, the type species of the family Quadriviridae, has a multipartite genome consisting of four monocistronic segments. Whereas most dsRNA virus capsids are based on dimers of a single protein, the ~450-Å-diameter, T = 1 RnQV1 capsid is built of P2 and P4 protein heterodimers, each with more than 1000 residues. Despite a lack of sequence similarity between …


Reducing Biomass Recalcitrance By Heterologous Expression Of A Bacterial Peroxidase In Tobacco (Nicotiana Benthamiana), Ayalew Ligaba-Osena, Bertrand Hankoua, Kay Dimarco, Robert Pace, Mark Crocker, Jesse Mcatee, Nivedita Nagachar, Ming Tien, Tom L. Richard Dec 2017

Reducing Biomass Recalcitrance By Heterologous Expression Of A Bacterial Peroxidase In Tobacco (Nicotiana Benthamiana), Ayalew Ligaba-Osena, Bertrand Hankoua, Kay Dimarco, Robert Pace, Mark Crocker, Jesse Mcatee, Nivedita Nagachar, Ming Tien, Tom L. Richard

Center for Applied Energy Research Faculty and Staff Publications

Commercial scale production of biofuels from lignocellulosic feed stocks has been hampered by the resistance of plant cell walls to enzymatic conversion, primarily owing to lignin. This study investigated whether DypB, the lignin-degrading peroxidase from Rodococcus jostii, depolymerizes lignin and reduces recalcitrance in transgenic tobacco (Nicotiana benthamiana). The protein was targeted to the cytosol or the ER using ER-targeting and retention signal peptides. For each construct, five independent transgenic lines were characterized phenotypically and genotypically. Our findings reveal that expression of DypB in the cytosol and ER does not affect plant development. ER-targeting increased protein accumulation, and …


Antibacterial Activity Of Endophytic Actinomycetes Isolated From The Medicinal Plant Vochysia Divergens (Pantanal, Brazil), Francielly M. W. Gos, Daiani C. Savi, Khaled A. Shaaban, Jon S. Thorson, Rodrigo Aluizio, Yvelise M. Possiede, Jürgen Rohr, Chirlei Glienke Sep 2017

Antibacterial Activity Of Endophytic Actinomycetes Isolated From The Medicinal Plant Vochysia Divergens (Pantanal, Brazil), Francielly M. W. Gos, Daiani C. Savi, Khaled A. Shaaban, Jon S. Thorson, Rodrigo Aluizio, Yvelise M. Possiede, Jürgen Rohr, Chirlei Glienke

Pharmaceutical Sciences Faculty Publications

Endophytic actinomycetes from medicinal plants produce a wide diversity of secondary metabolites (SM). However, to date, the knowledge about endophytes from Brazil remains scarce. Thus, we analyzed the antimicrobial potential of 10 actinomycetes isolated from the medicinal plant Vochysia divergens located in the Pantanal sul-mato-grossense, an unexplored wetland in Brazil. Strains were classified as belonging to the Aeromicrobium, Actinomadura, Microbacterium, Microbispora, Micrococcus, Sphaerisporangium, Streptomyces, and Williamsia genera, through morphological and 16S rRNA phylogenetic analyzes. A susceptibility analysis demonstrated that the strains were largely resistant to the antibiotics oxacillin and nalidixic acid. Additionally, different culture media (SG and R5A), and …


Multiple Origins Of Endosymbionts In Chlorellaceae With No Reductive Effects On The Plastid Or Mitochondrial Genomes, Weishu Fan, Wenhu Guo, James L. Van Etten, Jeffrey P. Mower Aug 2017

Multiple Origins Of Endosymbionts In Chlorellaceae With No Reductive Effects On The Plastid Or Mitochondrial Genomes, Weishu Fan, Wenhu Guo, James L. Van Etten, Jeffrey P. Mower

James Van Etten Publications

Ancient endosymbiotic relationships have led to extreme genomic reduction in many bacterial and eukaryotic algal endosymbionts. Endosymbionts in more recent and/or facultative relationships can also experience genomic reduction to a lesser extent, but little is known about the effects of the endosymbiotic transition on the organellar genomes of eukaryotes. To understand how the endosymbiotic lifestyle has affected the organellar genomes of photosynthetic green algae, we generated the complete plastid genome (plastome) and mitochondrial genome (mitogenome) sequences from three green algal endosymbionts (Chlorella heliozoae, Chlorella variabilis and Micractinium conductrix). The mitogenomes and plastomes of the three newly sequenced endosymbionts …


The Role Of Co-Opted Escrt Proteins And Lipid Factors In Protection Of Tombusviral Double-Stranded Rna Replication Intermediate Against Reconstituted Rnai In Yeast, Nikolay Kovalev, Jun-Ichi Inaba, Zhenghe Li, Peter D. Nagy Jul 2017

The Role Of Co-Opted Escrt Proteins And Lipid Factors In Protection Of Tombusviral Double-Stranded Rna Replication Intermediate Against Reconstituted Rnai In Yeast, Nikolay Kovalev, Jun-Ichi Inaba, Zhenghe Li, Peter D. Nagy

Plant Pathology Faculty Publications

Reconstituted antiviral defense pathway in surrogate host yeast is used as an intracellular probe to further our understanding of virus-host interactions and the role of co-opted host factors in formation of membrane-bound viral replicase complexes in protection of the viral RNA against ribonucleases. The inhibitory effect of the RNA interference (RNAi) machinery of S. castellii, which only consists of the two-component DCR1 and AGO1 genes, was measured against tomato bushy stunt virus (TBSV) in wild type and mutant yeasts. We show that deletion of the co-opted ESCRT-I (endosomal sorting complexes required for transport I) or ESCRT-III factors makes …


Induction And Suppression Of Antiviral Rna Silencing By Tomato Spotted Wilt Virus, Sergio M. Gabriel Peralta Jul 2017

Induction And Suppression Of Antiviral Rna Silencing By Tomato Spotted Wilt Virus, Sergio M. Gabriel Peralta

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

Tomato spotted wilt virus (TSWV) is an emerging pathogen with wide host range and one of the most important viruses of plants. Information regarding processing of negative single stranded RNA viruses such as TSWV in the RNA silencing pathway remains limited. In nature TSWV is only transmitted by thrips as vectors and since infection occurs in both thrips and plants, an experimental system to transmit using thrips and the detection of TSWV were established. In order to understand the processing of TSWV in the RNA silencing pathway, Arabidopsis thaliana as a model plant was used in the genetic analysis against …


Swainsonine Biosynthesis Genes In Diverse Symbiotic And Pathogenic Fungi, Daniel Cook, Bruno G. G. Donzelli, Rebecca Creamer, Deana L. Baucom, Dale R. Gardner, Juan Pan, Neil Moore, Stuart B. Krasnoff, Jerzy W. Jaromczyk, Christopher L. Schardl Jun 2017

Swainsonine Biosynthesis Genes In Diverse Symbiotic And Pathogenic Fungi, Daniel Cook, Bruno G. G. Donzelli, Rebecca Creamer, Deana L. Baucom, Dale R. Gardner, Juan Pan, Neil Moore, Stuart B. Krasnoff, Jerzy W. Jaromczyk, Christopher L. Schardl

Plant Pathology Faculty Publications

Swainsonine—a cytotoxic fungal alkaloid and a potential cancer therapy drug—is produced by the insect pathogen and plant symbiont Metarhizium robertsii, the clover pathogen Slafractonia leguminicola, locoweed symbionts belonging to Alternaria sect. Undifilum, and a recently discovered morning glory symbiont belonging to order Chaetothyriales. Genome sequence analyses revealed that these fungi share orthologous gene clusters, designated “SWN,” which included a multifunctional swnKgene comprising predicted adenylylation and acyltransferase domains with their associated thiolation domains, a β-ketoacyl synthase domain, and two reductase domains. The role of swnK was demonstrated by inactivating it in M. robertsii through homologous …


Identification Of Intrahelical Bifurcated H‑Bonds As A New Type Of Gate In K+ Channels, Oliver Rauh, Martin Urban, Leonhard M. Henkes, Tobias Winterstein, Timo Greiner, James L. Van Etten, Anna Moroni, Stefan M. Kast, Gerhard Thiel, Indra Schroeder May 2017

Identification Of Intrahelical Bifurcated H‑Bonds As A New Type Of Gate In K+ Channels, Oliver Rauh, Martin Urban, Leonhard M. Henkes, Tobias Winterstein, Timo Greiner, James L. Van Etten, Anna Moroni, Stefan M. Kast, Gerhard Thiel, Indra Schroeder

James Van Etten Publications

Gating of ion channels is based on structural transitions between open and closed states. To uncover the chemical basis of individual gates, we performed a comparative experimental and computational analysis between two K+ channels, KcvS and KcvNTS. These small viral encoded K+ channel proteins, with a monomer size of only 82 amino acids, resemble the pore module of all complex K+ channels in terms of structure and function. Even though both proteins share about 90% amino acid sequence identity, they exhibit different open probabilities with ca. 90% in KcvNTS and 40% in KcvS. …


Virus-Mediated Suppression Of Host Non-Self Recognition Facilitates Horizontal Transmission Of Heterologous Viruses, Songsong Wu, Jiasen Cheng, Yanping Fu, Tao Chen, Daohong Jiang, Said A. Ghabrial, Jiatao Xie Mar 2017

Virus-Mediated Suppression Of Host Non-Self Recognition Facilitates Horizontal Transmission Of Heterologous Viruses, Songsong Wu, Jiasen Cheng, Yanping Fu, Tao Chen, Daohong Jiang, Said A. Ghabrial, Jiatao Xie

Plant Pathology Faculty Publications

Non-self recognition is a common phenomenon among organisms; it often leads to innate immunity to prevent the invasion of parasites and maintain the genetic polymorphism of organisms. Fungal vegetative incompatibility is a type of non-self recognition which often induces programmed cell death (PCD) and restricts the spread of molecular parasites. It is not clearly known whether virus infection could attenuate non-self recognition among host individuals to facilitate its spread. Here, we report that a hypovirulence-associated mycoreovirus, named Sclerotinia sclerotiorum mycoreovirus 4 (SsMYRV4), could suppress host non-self recognition and facilitate horizontal transmission of heterologous viruses. We found that cell death in …


Draft Genome Sequence Of Cercospora Sojina Isolate S9, A Fungus Causing Frogeye Leaf Spot (Fls) Disease Of Soybean, Fanchang Zeng, Chaofan Wang, Guirong Zhang, Junmei Wei, Carl A. Bradley, Ray Ming Mar 2017

Draft Genome Sequence Of Cercospora Sojina Isolate S9, A Fungus Causing Frogeye Leaf Spot (Fls) Disease Of Soybean, Fanchang Zeng, Chaofan Wang, Guirong Zhang, Junmei Wei, Carl A. Bradley, Ray Ming

Plant Pathology Faculty Publications

Fungi are the causal agents of many of the world's most serious plant diseases causing disastrous consequences for large-scale agricultural production. Pathogenicity genomic basis is complex in fungi as multicellular eukaryotic pathogens. The fungus Cercospora sojina is a plant pathogen that threatens global soybean supplies. Here, we report the genome sequence of C. sojina strain S9 and detect genome features and predicted genomic elements. The genome sequence of C. sojina is a valuable resource with potential in studying the fungal pathogenicity and soybean host resistance to frogeye leaf spot (FLS), which is caused by C. sojina. …


A Comparative Genomic Analysis Of Putative Pathogenicity Genes In The Host-Specific Sibling Species Colletotrichum Graminicola And Colletotrichum Sublineola, Ester A. S. Buiate, Katia Viana Xavier, Neil Moore, Maria F. Torres, Mark L. Farman, Christopher L. Schardl, Lisa J. Vaillancourt Jan 2017

A Comparative Genomic Analysis Of Putative Pathogenicity Genes In The Host-Specific Sibling Species Colletotrichum Graminicola And Colletotrichum Sublineola, Ester A. S. Buiate, Katia Viana Xavier, Neil Moore, Maria F. Torres, Mark L. Farman, Christopher L. Schardl, Lisa J. Vaillancourt

Plant Pathology Faculty Publications

Background: Colletotrichum graminicola and C. sublineola cause anthracnose leaf and stalk diseases of maize and sorghum, respectively. In spite of their close evolutionary relationship, the two species are completely host-specific. Host specificity is often attributed to pathogen virulence factors, including specialized secondary metabolites (SSM), and small-secreted protein (SSP) effectors. Genes relevant to these categories were manually annotated in two co-occurring, contemporaneous strains of C. graminicola and C. sublineola. A comparative genomic and phylogenetic analysis was performed to address the evolutionary relationships among these and other divergent gene families in the two strains.

Results: Inoculation of maize with C. sublineola …


The Family Rhabdoviridae: Mono- And Bipartite Negative-Sense Rna Viruses With Diverse Genome Organization And Common Evolutionary Origins, Ralf G. Dietzgen, Hideki Kondo, Michael M. Goodin, Gael Kurath, Nikos Vasilakis Jan 2017

The Family Rhabdoviridae: Mono- And Bipartite Negative-Sense Rna Viruses With Diverse Genome Organization And Common Evolutionary Origins, Ralf G. Dietzgen, Hideki Kondo, Michael M. Goodin, Gael Kurath, Nikos Vasilakis

Plant Pathology Faculty Publications

The family Rhabdoviridae consists of mostly enveloped, bullet-shaped or bacilliform viruses with a negative-sense, single-stranded RNA genome that infect vertebrates, invertebrates or plants. This ecological diversity is reflected by the diversity and complexity of their genomes. Five canonical structural protein genes are conserved in all rhabdoviruses, but may be overprinted, overlapped or interspersed with several novel and diverse accessory genes. This review gives an overview of the characteristics and diversity of rhabdoviruses, their taxonomic classification, replication mechanism, properties of classical rhabdoviruses such as rabies virus and rhabdoviruses with complex genomes, rhabdoviruses infecting aquatic species, and plant rhabdoviruses with both mono- …


Structure Of The Chlorovirus Pbcv-1 Major Capsid Glycoprotein Determined By Combining Crystallographic And Carbohydrate Molecular Modeling Approaches, Cristina De Castro, Thomas Klose, Immacolata Speciale, Rosa Lanzetta, Antonio Molinaro, James L. Van Etten, Michael G. Rossmann Jan 2017

Structure Of The Chlorovirus Pbcv-1 Major Capsid Glycoprotein Determined By Combining Crystallographic And Carbohydrate Molecular Modeling Approaches, Cristina De Castro, Thomas Klose, Immacolata Speciale, Rosa Lanzetta, Antonio Molinaro, James L. Van Etten, Michael G. Rossmann

James Van Etten Publications

The glycans of the major capsid protein (Vp54) of Paramecium bursaria chlorella virus (PBCV-1) were recently described and found to be unusual. This prompted a reexamination of the previously reported Vp54 X-ray structure. A detailed description of the complete glycoprotein was achieved by combining crystallographic data with molecular modeling. The crystallographic data identified most of the monosaccharides located close to the protein backbone, but failed to detect those further from the glycosylation sites. Molecular modeling complemented this model by adding the missing monosaccharides and examined the conformational preference of the whole molecule, alone or within the crystallographic environment. Thus, combining …