Life Sciences Commons^™

Comparison Of Compost Tea And Biological Fungicides For Control Of Early Blight In Organic Heirloom Tomato Production, Richard Kouyoumjian

All Theses

The efficacy of compost tea was evaluated and compared alone and in combination with two biofungicides Serenade Max and Sonata for control of early blight caused by the fungal pathogen Alternaria tomatophila on tomato Solanum lycopersicum (L), heirloom cultivar `Cherokee Purple'. Results of field experiments over two growing seasons indicated that compost tea provided a low level of protection against early blight. The results were variable; most likely due to dry conditions and the presence of bacterial wilt the first year and tomato spotted wilt virus the second year. In both 2006 and 2007 field trials compost tea was not …

A Revision Of Tomoceridae (Insecta: Collembola) In Great Smoky Mountains National Park And Southern Appalachians Using Morphological And Molecular Approaches, Kelly Lynn Felderhoff

Masters Theses

Large, heavily scaled tomocerid springtails (Collembola) are abundant in eastern forests, and are important components of the detrital food web. The genus Pogonognathellus predominates in the southern Appalachians While a number of well-delimited tomocerid species have been described, others have vague morphological boundaries and appear to be species complexes. Before this study began in 2005, four species were known to occur in Great Smoky Mountains National Park (GSMNP) and the surrounding Appalachians (P. bidentatus, dubius, elongatus, flavescens). Also occurring throughout the area is Tomocerus lamellifera, a widespread and distinctive species. The goals of this project were to …

Wheat Streak Mosaic Virus Lacking Helper Component-Proteinase Is Competent To Produce Disease Synergism In Double Infections With Maize Chlorotic Mottle Virus, Drake C. Stenger, Brock A. Young, Feng Qu, Thomas Jack Morris, Roy French

Department of Plant Pathology: Faculty Publications

The tritimovirus Wheat streak mosaic virus (WSMV) and the machlomovirus Maize chlorotic mottle virus (MCMV) each cause systemic chlorosis in infected maize plants. Infection of maize with both viruses produces corn lethal necrosis disease (CLND). Here, we report that complete deletion of the WSMV helper component-proteinase (HC-Pro) coding region had no effect on induction of CLND symptoms following coinoculation of maize with WSMV and MCMV. We further demonstrated that elevation of virus titers in double infections, relative to single infections, also was independent of WSMV HC-Pro. Thus, unlike potyvirus HC-Pro, WSMV HC-Pro was dispensable for disease synergism. Because disease synergism …

Heritability Of Latent Period Estimated From Wild-Type And Selected Populations Of Puccinia Triticina, Jeffery S. Lehman, Gregory Shaner

Biology and Earth Science Faculty Scholarship

Durability of partially resistant wheat cultivars to wheat leaf rust depends on the amount of genetic variation in parasitic fitness within populations of the pathogen Puccinia triticina. To assess the durability of partial resistance, selection experiments were used to explore quantitative variation in parasitic fitness of P. triticina. Fungal populations 881-WT and 882-WT were selected for shortened latent period on partially resistant cvs. CI 13277 and Sw 72469-6 for multiple generations. Fitness components were measured for wild-type and selected fungal populations. Responses to selection and selection differentials were calculated, and broad-sense, realized heritabilities for latent period were estimated for wild-type …

Induction Of Systemic Acquired Resistance In Cotton Foliage Does Not Adversely Affect The Performance Of An Entomopathogen, Ruth C. Plymale, Gary W. Felton, Kelli Hoover

Articles

Baculoviral efficacy against lepidopteran larvae is substantially impacted by the host plant. Here, we characterized how baculoviral pathogenicity to cotton-fed Heliothis virescens larvae is affected by induction of systemic acquired resistance (SAR). Numerous studies have shown that SAR induced by the plant elicitor benzo-(1,2,3)-thiadiazole-7- carbothioic acid S-methyl ester (BTH) can protect against plant pathogens, but reports on the impacts of SAR on chewing herbivores or on natural enemies of herbivores are few. We found that BTH application significantly increased foliar peroxidase activity, condensed tannin levels, and total phenolic levels but did not alter dihydroxyphenolic levels. Consumption of BTH-treated foliage did …

The Strength Of Seeds And Their Destruction By Granivorous Insects, Jonathan G. Lundgren, Kurt A. Rosentrater

Kurt A. Rosentrater

The influence of seed structure and strength on their destruction by granivores is central to understanding the dynamics of granivore-plant interactions. For up to nine seed species, the effects of seed size (cm3), mass (mg), density (mg/cm3) and coat strength (MPa) on the damage inflicted by three post-dispersal granivores (Harpalus pensylvanicus, Anisodactylus sanctaecrucis, and Gryllus pennsylvanicus) were evaluated. Seed destruction rates by G. pennsylvanicus were statistically unrelated to the size and toughness of the seeds. Seed densities significantly affected their destruction by A. sanctaecrucis and H. pensylvanicus, as did seed size, mass, and strength in H. pensylvanicus under choice conditions. …

Genetic Diversity In Populations Of Xanthomonas Campestris Pv. Campestris In Cruciferous Weeds In Central Coastal California, A. Ignatov, A. Sechler, E. L. Schuenzel, Irina V. Agarkova, B. Oliver, A. K. Vidaver, N. W. Schaad

Department of Plant Pathology: Faculty Publications

Xanthomonas campestris pv. campestris (X. campestris) infects a large number of cruciferous plants, including weeds. California has one of the largest and most diverse populations of wild cruciferous plants in the world. Although considerable information is available on the genetic diversity of X. campestris in commercial crop plants, nothing is known about the diversity in strains infecting weeds. To assess the genetic diversity among strains of X. campestris in weeds in noncultivated and cultivated areas, strains of the pathogen were isolated from populations of cruciferous weeds growing in coastal valley crop-production sites and from remote nonproduction sites along the …

Soybean Fgam Synthase Promoters Useful In Nematode Control: U.S. Patent No. Us 7,223,901 B2, Sally Ann Mackenzie, Zarir Vaghchhipawala

Department of Plant Pathology: Faculty Publications

The subject invention relates to nematode responsive domains obtained from soybean promoters for phosphoribosylformylglycinamidine ribonucleotide (FGAM) synthase paralogs. The nematode responsive domains can be used in promoters that are linked to heterologous DNA. Such constructs can be expressed in transfected or transformed soybean and used in the control of nematode infection of soybean.

Pseudomonas Avr And Hop Proteins, Their Encoding Nucleic Acids, And Use Thereof, James R. Alfano, Alan Collmer, Samuel W. Cartinhour, David J. Schneider

Department of Plant Pathology: Faculty Publications

One aspect of the present invention relates to isolated nucleic acid molecules encoding avirulence proteins or polypeptides of Pseudomonas syringae pv. syringae DC 3000, or nucleic acid moleculues which are complementary thereto. Expression vectors, host cells, and transgenic plants which include the DNA molecules of the present invention are also disclosed. Another aspect relates to the isolated proteins or polypeptides and compositions containing the same. The various nucleic acid molecules and proteins of the present invention can be used to impart disease resistance to a plant, make a plant hypersusceptible to colonization by nonpathogenic bacteria, modify a metabolic pathway in …

Life History Of Hemlock Woolly Adelgid, Adelges Tsugae Annand, On Eastern Hemlock, Tsuga Canadensis (L.) Carriere, In The Southern Appalachians And Assessment Of Egg Releases Of Sasajiscymnus Tsugae (Sasaji And Mcclure) For Its Management, Isaac K. Deal

Masters Theses

Studies were conducted in 2005 and 2006 at Baxter Orchard, Great Smoky Mountains National Park, Tennessee to optimize survival of Sasajiscymnus tsugae (St) (Sasaji and McClure) released as eggs on eastern hemlock, Tsuga canadensis (L.) Carriere, for biological control of Adelges tsugae (HWA) Annand. Studies investigated annual abundance and seasonality of HWA lifestages, weekly field and laboratory survival of St, and survival of St egg cohorts of various ages and densities. HWA was determined to be bivoltine on eastern hemlock in Tennessee with an aestivation period between July and October. Lifestages preferred as food by St were present from …

Cultural Control Methods That Effect The Development And Spread Of Corynespora Cassiicola (Berk. & Curt.) Wei On African Violet (Saintpaulia Ionantha Wendl.), Hillary Dawn Ross

Masters Theses

In recent years, a large commercial grower of African violets (Saintpaulia ionantha Wendl.) in middle Tennessee has experienced epidemics of Corynespora leaf spot caused by Corynespora cassiicola (Berk. & Curt.) Wei (Alan Windham, personal communication). Symptoms of Corynespora leaf spot include rapidly expanding circular lesions on the surface of the leaves and petioles. The disease occurs in propagation material and mature plants of S. ionantha which result in thousands of plants being discarded daily. The objectives of this research were to: 1) determine if irrigation methods affected disease severity, 2) to determine if fungicidal spray intervals could be extended …

Genetic Structure In Natural Populations Of Barley/Cereal Yellow Dwarf Virus Isolates From Alaska, N.L. Robertson, Roy C. French

Department of Plant Pathology: Faculty Publications

The genetic structure of natural populations of Alaskan barley yellow dwarf virus (BYDV)-PAV, BYDV-PAS, and cereal yellow dwarf virus (CYDV)- RPV from barley (Hordeum vulgare L.) and oats (Avena sativa L.) in Alaska were analyzed between 2002 and 2004. PCR products spanning the viral coat protein gene of 187 isolates were cloned and sequenced. The majority (78%) were similar to BYDV-PAS, 19% were similar to CYDV-RPV, and only about 3% resembled BYDV-PAV. The CYDVRPV isolates clustered in three groups: 44, 17, and 39% resembled RPS-like CP from Mexico, resembled RPV-like CP from New York, or formed a unique …

Functional Characterization Of The Aspergillus Fumigatus Calcineurin, Márcia Eliana Da Silva Ferreira, Thorsten Heinekamp, Albert Hartl, Axel A. Brakhage, Camile P. Semighini, Steven D. Harris, Marcela Savoldi, Paula Fagundes De Gouvêa, Maria Helena De Souza Goldman, Gustavo H. Goldman

Department of Plant Pathology: Faculty Publications

Aspergillus fumigatus is an aggressive opportunistic pathogen of humans as well as a major allergen. Environmental sensing and retrieving essential nutrients from the environment are general metabolic traits associated with the growth of this saprophytic fungus. Two important mediators of calcium signals in eukaryotic cells are the Ca²⁺-binding protein calmodulin and the Ca²⁺/calmodulin-dependent phosphatase calcineurin. Calcineurin is a heterodimer that consists of a catalytic subunit A and a Ca²⁺/calmodulin binding unit. We deleted the A. fumigatus calA gene, which encodes the calcineurin A catalytic subunit, and demonstrated that this gene is not essential in …

Loline Alkaloid Gene Clusters Of The Fungal Endophyte Neotyphodium Uncinatum, Christopher L. Schardl, Heather H. Wilkinson, Martin J. Spiering

Plant Pathology Faculty Patents

Loline alkaloids (LA), which are 1-aminopyrrolizidines with an oxygen bridge, are produced by Epichloë (anamorph=Neotyphodium) species, endophytes of grasses. LA are insecticidal, thus helping protect host plants from insect herbivory. Suppression subtractive hybridization PCR was used to isolate transcripts up-regulated during loline alkaloid production in cultures of Neotyphodium uncinatum. Subtracted cDNAs were cloned, and a λ-phage cDNA library from an LA-expressing N. uncinatum culture was screened with subtracted cDNA. In BLAST searches, several cDNAs identified had sequence similarities to aspartate kinases, and another with O-acetylhomoserine-(thiol)lyase. Differential expression of these two genes in LA-producing cultures of N. uncinatum …

A Pseudomonas Syringae Pv. Tomato Dc3000 Mutant Lacking The Type Iii Effector Hopq1-1 Is Able To Cause Disease In The Model Plant Nicotiana Benthamiana, Chia-Fong Wei, Brian H. Kvitko, Rena Shimizu, Emerson Crabill, James R. Alfano, Nai-Chun Lin, Gregory B. Martin, Hsiou-Chen Huang, Alan Collmer

Center for Plant Science Innovation: Faculty and Staff Publications

The model pathogen Pseudomonas syringae pv. tomato DC3000 causes bacterial speck in tomato and Arabidopsis, but Nicotiana benthamiana, an important model plant, is considered to be a non-host. Strain DC3000 injects approximately 28 effector proteins into plant cells via the type III secretion system (T3SS). These proteins were individually delivered into N. benthamiana leaf cells via T3SS-proficient Pseudomonas fluorescens, and eight, including HopQ1-1, showed some capacity to cause cell death in this test. Four gene clusters encoding 13 effectors were deleted from DC3000: cluster II (hopH1, hopC1), IV (hopD1, hopQ1-1, hopR1), IX (hopAA1-2, hopV1, hopAO1, hopG1), and native plasmid pDC3000A …

Crop Updates 2007 - Weeds, Alexandra Douglas, Peter Newman, Sally Peltzer, Abul Hashem, Aik Cheam, Siew Lee, Natalie Maguire, Michael Walsh, Dan Cornally, Matt Willis, Glen Riethmuller, Shahab Pathan, Michael Renton, Art Diggle, Mechelle Owen, Stephen Powles, Roberto Busi, Robert Barrett-Lennard, Andrew Storrie, David Minkey, Craig A. Ruchs, Peter Boutsalis, Catherine Borger, Nerys Wilkins, Julie Roche, Martin Harries, John Peirce, Brad Rayner, John Moore, Ray Fulwood, Chris Roberts, Paul Matson, Bob French, Laurie Maiolo, Lorne Mills, Harmohinder Dhammu, Ben Tan, Vince Lambert, Chris Roberts, Vanessa Stewart

Crop Updates

This session covers thirty two papers from different authors:

1. ACKNOWLEDGEMENTS, Alexandra Douglas CONVENOR – WEEDS DEPARTMENT OF AGRICULTURE AND FOOD

WILD RADISH MANAGEMENT

2. Decimate a wild radish seed bank in five years, Peter Newman, Sally Peltzer, Abul Hashem and Aik Cheam, Department of Agriculture and Food

3. High level of seed-set control in wild radish is achievable, Aik Cheam and Siew Lee,Department of Agriculture and Food

4. Wild radish: Best management practice, Aik Cheam and Siew Lee, Department of Agriculture and Food

5. Control of phenoxy resistant wild radish through the combined effects of wheat …

Crop Updates 2007 - Lupins, Pulses And Oilseeds, Mark Seymour, Jacinta Falconer, Ian Pritchard, Rodger Beermier, Wayne Parker, Martin Harries, Kedar Adhikari, Geoff Thomas, Peter White, Bevan Burichell, Mike Baker, Bob French, Jo Walker, Laurie Maiolo, Leigh Smith, Mark Sweetingham, Lorne Mills, Harmohinder Dhammu, Ben Tang, Qifu Ma, Zed Rengel, Bill Bowden, Ross Brennan, Reg Lunt, Tim Hilder, Tim Maling, A. Diggle, D. Thackray, R. A.C. Jones, K. H.M. Siddique, Vijay Jayasena, Leonardus Kardono, Ken Quail, Ranil Coorey, Hannah Williams, Don Elani Jayawardena, Kerry Regan, Rod Hunter, Tanveer Khan, Jenny Garlinge, Heather Clarke, W. Macleod, S. Morgan, A. Harris, Alan Meldrum, Helen Bowers, A. Bakr, Phillip Chambers, Chris Veitch, Tony Leonforte, Pam Burgess, Leanne Young, Brenda Coutts, Donna O'Keefe, Rhonda Pearce, Monica Kehoe, Terri Jasper, Tim Pope, Michael Materne, Ping Si, Mike Walsh, H. H. T. Phan, S. R. Ellwood, J. Hane, A. Williams, R. Ford, S. Thomas, R. Oliver, Katie Robinson, Mohammad Amjad, Graham Walton, Pat Fels, Andy Sutherland, Imma Farre, Michael Robertson, Senthold Asseng3, Ravjit Khangura, Moin Salam

Crop Updates

This session covers forty eight papers from different authors:

2006 REGIONAL ROUNDUP

1. South east agricultural region, Mark Seymour¹ and Jacinta Falconer², ¹Department of Agriculture and Food, ²Cooperative Bulk Handling Group

2. Central agricultural region, Ian Pritchard, Department of Agriculture and Food

3. Great Southern and Lakes region, Rodger Beermier, Department of Agriculture and Food

4. Northern agricultural region, Wayne Parker and Martin Harries, Department of Agriculture and Food

LUPINS

5. Development of anthracnose resistant and early flowering albus lupins (Lupinus albus L) in Western Australia, Kedar Adhikari and Geoff Thomas, Department of …

Crop Updates 2007 - Farming Systems, David Jeffries, A. Loi, B. J. Nutt, C. K. Revell, Yvette Oliver, Michael Robertson, Bill Bowden, Kit Leake, Ashley Bonser, Ian Maling, Bindi Isbister, Garren Knell, Alison Slade, David Stephens, Michael Meuleners, David Beard, Nicolyn Short, Rob Grima, Ingrid Richardson, Ruhi Ferdowsian, Geoff Bee, David Evans, Bob Gilkes, Senthold Asseng, Jim Dixon, Felicity Byrne, Mike Ewing, Dennis Van Gool, Louise Barton, Ralf Kiese, David Gatter, Klaus Butterbach-Bahl, Renee Buck, Christoph Hinz, Daniel Murphy, Cameron Weeks, Meredith Fairbanks, John Peirce, Brad Rayner, Sandy White, Paul Damon, Qifa Ma, Zed Rengel, Ed Barrett-Lennard, Meir Altman, Tracey M. Gianatti, Lindsay Bell, Ben Webb, Caroline Peek, Paul Sanford, Paul Blackwell, Glen Riethmuller, Darshan Sharma, Mike Collins, Frank D'Emden, David Hall, G. P. Manango, D. L. Steverson, Vanessa Stewart, Julie Roche, Peter Rutherford, Imma Farré, Ian Foster, Stephen Charles, Frances Hoyle, N. Milton, M. Osman, L. K. Abbott, W. R. Cookson, S. Darmawanto, Rob Sands, David Mccarthy, Paul Carmody, J. Russell, J. Eyres, G. Fosbery, A. Roe, Phil Nichols, Andrew Bathgate, Anne Wilkins

Crop Updates

This session covers forty papers from different authors:

1. Quality Assurance and industry stewardship, David Jeffries, Better Farm IQ Manager, Cooperative Bulk Handling

2. Sothis: Trifolium dasyurum (Eastern Star clover), A. Loi, B.J. Nutt and C.K. Revell, Department of Agriculture and Food

3. Poor performing patches of the paddock – to ameliorate or live with low yield? Yvette Oliver¹, Michael Robertson¹, Bill Bowden², Kit Leake³and Ashley Bonser³, CSIRO Sustainable Ecosystems¹, Department of Food and Agriculture², Kellerberrin Farmer³

4. What evidence is there that …

Crop Updates 2007 - Cereals, R. Loughman, R. Lance, I. Barclay, G. Crosbie, S. Harasymow, W. Lambe, C. Li, R. Mclean, C. Moore, K. Stefanova, A. Tarr, R. Wilson, Matu Peipi, Matt Whiting, Christine Zaicou, Shahajahan Miyan, Brenda Shackley, Len J. Wade, Lindsay W. Bell, Felicity Byrne (Nee Flugge), Mike A. Ewing, Blakely Paynter, Andrea Hills, Raj Malik, Kelly Winfield, Harmohinder Dhammu, Vince Lambert, Chris Roberts, Jeromy Lemon, Geoff Thomas, Ian Hartley, Andrew Taylor, Manisha Shankar, John Majewski, Vivien Vanstone, Brenda Coutts, Monica Kehoe, Roger Jones, Geoffrey Dwyer, Belinda Welsh, Cuiping Wang, Linda Price

Crop Updates

This session covers twenty six papers from different authors:

CEREAL BREEDING

1. Strategies for aligning producer and market imperatives in cereal breeding in Western Australia, R. Loughman, R. Lance, I. Barclay, G. Crosbie, S. Harasymow, W. Lambe, C. Li, R. McLean, C. Moore, K. Stefanova, A. Tarr and R. Wilson, Department of Agriculture and Food

2. LongReach plant breeders wheat variety trials – 2006, Matu Peipi and Matt Whiting, LongReach Plant Breeders

WHEAT AGRONOMY

3. Response of wheat varieties to sowing time in the northern agricultural region in 2006, Christine Zaicou, Department of Agriculture and Food

4. Response …

Proceedings Of The 34th Annual Meeting Of The Southern Soybean Disease Workers (February 18-19, 2007, St. Louis, Missouri), Daniel H. Poston, Michael E. Schmidt, J. Allen Wrather, Jason Bond, Stephen R. Koenning

Southern Soybean Disease Workers: Conference Proceedings

Southern United States Soybean Disease Loss Estimates for 2006. SR Koenning

Stratego 250 EC, Broad Spectrum Disease Control in Soybeans. JR Bloomberg, RA Myers, and R Kraus

Asian Soybean Rust: Efficacy of Selected Fungicides and Observations on Their Use. RW Schneider, CL Clark, EP Mumma, and CG Giles

Effects of Light Intensity and Darkness Period on Infection of Soybean Rust in Controlled Conditions. J Mo, T Guo, X Li, and XB Yang

Identification of Maturity Group 3 and 4 Soybean Cultivars and Lines Resistant to Cercospora sojina by Field Screening and Molecular Markers. A Wrather, R Mian, G Shannon, J …

2006 Lowbush Blueberry Project Reports, Kristi Crowe, Alfred A. Bushway, Rodney J. Bushway, Vivian Ch Wu, Brian Perkins, Pam Small, Darrell Donahue, Frank Drummond, Judith Collins, Floyd Dowell, Dorothy J. Klimis-Zacas, Mary Ellen Camire, Gordon Starr, David E. Yarborough, S Hoffmann, Daniel J. Bell, Seanna L. Annis, Tamara Levitsky, Loretta Kreider, Kristen Mcgovern, K Frost, John M. Smagula, Qian Wang, Kerry Fl Guiseppe

Wild Blueberry Research Reports

The 2006 edition of the Lowbush Blueberry Project Reports was prepared for the Wild Blueberry Commission of Maine and the Wild Blueberry Advisory Committee by researchers at the University of Maine, Orono. Projects in this report include:

1. Evaluation of Emerging Disinfection Technologies for Wild Blueberry Processing

2. Incorporation of wild blueberry puree into a soy-based burger and its effect on sensory and chemical properties of the broiled burgers

3. Infestation Detection using NIRS

4. Mechanism of Action through which Wild Blueberries affect Arterial Functional Properties in Normotensive and Spontaneously Hypertensive Rats

5. Practical Microbial Control Approach for Wild Blueberries …

Association Of Ergot Alkaloids With Conidiation In Aspergillus Fumigatus, Christine M. Coyle, Shawn C. Kenaley, William R. Rittenour, Daniel G. Panaccione

Department of Plant Pathology: Faculty Publications

Ergot alkaloids are mycotoxins that affect the nervous and reproductive systems of exposed individuals through interactions with monoamine receptors. They have been studied more widely in ergot fungi and grass endophytes but also are found in Aspergillus fumigatus, an opportunistic human pathogen that reproduces and disseminates exclusively through conidia. The ergot alkaloids festuclavine and fumigaclavines A, B and C are present in or on conidia of A. fumigatus. Cultures of the fungus that are free of conidia are difficult to obtain, obscuring comparisons of conidia versus vegetative hyphae as sources of the ergot alkaloids. To create conidiation-deficient strains of A. …

Expression Analysis Of Rice Defense-Related Genes In Turfgrass In Response To Magnaporthe Grisea, Young-Ki Jo, Guo-Liang Wang, Michael J. Boehm

Department of Plant Pathology: Faculty Publications

Magnaporthe grisea (anamorph = Pyricularia grisea) causes blast on rice (Oryza sativa) and gray leaf spot on turfgrass. Gray leaf spot is a serious disease on St. Augustinegrass (Stenotaphrum secundatum), perennial ryegrass (Lolium perenne), and tall fescue (Festuca arundinacea). Virulence assays performed in this study revealed that M. grisea collected from rice could also cause disease on St. Augustinegrass and tall fescue. One rice isolate, Che86061, caused similar disease reactions on susceptible cultivars of rice and St. Augustinegrass and an incompatible interaction on resistant cultivars of both species. To explore whether …

Genetic Analysis Of A Novel Alaska Barley Yellow Dwarf Virus In The Family Luteoviridae, N.L. Robertson, Roy C. French

Department of Plant Pathology: Faculty Publications

A new plant virus belonging to the family Luteoviridae and isolated from diseased oat (Avena sativa L.) plants was discovered in Alaska in 2003. Even though plants with red/orange leaves were indicative of barley yellow dwarf disease, they were not reactive to specific antibodies corresponding to barley yellow dwarf virus (BYDV)-MAV, -PAV, -SGV, and cereal yellow dwarf virus-RPV from enzyme-linked immunosorbent assays (ELISA). An alternative RT-PCR assay that incorporated Shu-F/Yan-R primers for detection of BYDV-MAV, -PAS, -PAV, and SGV was effective in producing ~830-nt fragments that contained genomic sequences to the 3’-terminus of the polymerase gene (ORF 2), the …

Genetic Diversity In Populations Of Xanthomonas Campestris Pv. Campestris In Cruciferous Weeds In Central Coastal California, A. Ignatov, A. Sechler, E. L. Schuenzel, I. Agarkova, B. Oliver, A. K. Vidaver, N. W. Schaad

Department of Plant Pathology: Faculty Publications

Xanthomonas campestris pv. campestris (X. campestris) infects a large number of cruciferous plants, including weeds. California has one of the largest and most diverse populations of wild cruciferous plants in the world. Although considerable information is available on the genetic diversity of X. campestris in commercial crop plants, nothing is known about the diversity in strains infecting weeds. To assess the genetic diversity among strains of X. campestris in weeds in noncultivated and cultivated areas, strains of the pathogen were isolated from populations of cruciferous weeds growing in coastal valley crop-production sites and from remote nonproduction sites along the …

Structure And Biosynthesis Of Heat-Stable Antifungal Factor (Hsaf), A Broad-Spectrum Antimycotic With A Novel Mode Of Action, Fengan Yu, Kathia Zaleta-Rivera, Xiangcheng Zhu, Justin Huffman, Jeffrey C. Millet, Steven D. Harris, Gary Yuen, Xing-Cong Li, Liangcheng Du

Department of Plant Pathology: Faculty Publications

A screen for antifungal compounds from Lysobacter enzymogenes strain C3, a bacterial biological control agent of fungal diseases, has previously led to the isolation of heat-stable antifungal factor (HSAF). HSAF exhibits inhibitory activities against a wide range of fungal species and shows a novel mode of antifungal action by disrupting the biosynthesis of a distinct group of sphingolipids. We have now determined the chemical structure of HSAF, which is identical to that of dihydromaltophilin, an antifungal metabolite with a unique macrocyclic lactam system containing a tetramic acid moiety and a 5,5,6-tricyclic skeleton. We have also identified the genetic locus responsible …

Structure And Function Of A Chlorella Virus Encoded Glycosyltransferase, Ying Zhang, Ye Xiang, James L. Van Etten, Michael G. Rossmann

James Van Etten Publications

Paramecium bursaria chlorella virus-1 encodes at least 5 putative glycosyltransferases that are probably involved in the synthesis of the glycan components of the viral major capsid protein. The 1.6 Å crystal structure of one of these glycosyltransferases (A64R) has a mixed α/β fold containing a central, six-stranded β-sheet flanked by α-helices. Crystal structures of A64R, complexed with UDP, CMP, or GDP, established that only UDP bound to A64R in the presence of Mn2+, consistent with its high structural similarity to glycosyltransferases which utilize UDP as the sugar carrier. The structure of the complex of A64R, UDP-glucose, and Mn2+ showed that …

Sequence And Annotation Of The 288-Kb Atcv-1 Virus That Infects An Endosymbiotic Chlorella Strain Of The Heliozoon Acanthocystis Turfacea, Lisa A. Fitzgerald, Michael V. Graves, Xiao Li, James Hartigan, Artur J.P. Pfitzner, Ella Hoffart, James L. Van Etten

James Van Etten Publications

Acanthocystis turfacea chlorella virus (ATCV-1), a prospective member of the family Phycodnaviridae, genus Chlorovirus, infects a unicellular, eukaryotic, chlorella-like green alga, Chlorella SAG 3.83, that is a symbiont in the heliozoon A. turfacea. The 288,047-bp ATCV-1 genome is the first virus to be sequenced that infects Chlorella SAG 3.83. ATCV-1 contains 329 putative protein-encoding and 11 tRNA-encoding genes. The protein-encoding genes are almost evenly distributed on both strands and intergenic space is minimal. Thirty-four percent of the viral gene products resemble entries in the public databases, including some that are unexpected for a virus. For example, these …

Chlorella Viruses Contain Genes Encoding A Complete Polyamine Biosynthetic Pathway, Sascha Baumann, Adrienne Sander, James Gurnon, Giane M. Yanai-Balser, James L. Van Etten, Markus Piotrowski

James Van Etten Publications

Two genes encoding the putative polyamine biosynthetic enzymes agmatine iminohydrolase (AIH) and N-carbamoylputrescine amidohydrolase (CPA) were cloned from the chloroviruses PBCV-1, NY-2A and MT325. They were expressed in Escherichia coli to form C-terminal (His)6-tagged proteins and the recombinant proteins were purified by Ni2+- binding affinity chromatography. The biochemical properties of the two enzymes are similar to AIH and CPA enzymes from Arabidopsis thaliana and Pseudomonas aeruginosa. Together with the previously known virus genes encoding ornithine/arginine decarboxlyase (ODC/ADC) and homospermidine synthase, the chloroviruses have genes that encode a complete set of functional enzymes that synthesize the rare polyamine homospermidine from arginine …

Response Of Soybean Cultivars To Bean Pod Mottle Virus Infection, Amy D. Ziems, Loren J. Giesler, George L. Graef, Margaret G. Redinbaugh, Jean L. Vacha, Sueann Berry, Laurence V. Madden, Anne E. Dorrance

Department of Plant Pathology: Faculty Publications

Bean pod mottle virus (BPMV) has become increasingly common in soybean throughout the north-central region of the United States. Yield loss assessments on southern soybean germplasm have reported reductions ranging from 3 to 52%. Currently, no soybean cultivars have been identified with resistance to BPMV. The objective of this study was to determine the impact of BPMV infection on soybean cultivars representing a broad range of northern soybean germplasm by comparing inoculated and noninoculated soybean plants in paired row studies. In all, 30 and 24 cultivars were evaluated in Nebraska (NE) in which soybean plants were inoculated at the V3 …