Plant Pathology Commons^™

An Evolutionary Perspective Of Pierce’S Disease Of Grapevine, Citrus Variegated Chlorosis, And Mulberry Leaf Scorch Diseases, Jianchi Chen, John S. Hartung, Chung-Jan Chang, Anne K. Vidaver

Department of Plant Pathology: Faculty Publications

Xylella fastidiosa causes diseases on a growing list of economically important plants. An understanding of how xylellae diseases originated and evolved is important for disease prevention and management. In this study, we evaluated the phylogenetic relationships of X. fastidiosa strains from citrus, grapevine, and mulberry through the analyses of random amplified polymorphic DNAs (RAPDs) and conserved 16S rDNA genes. RAPD analysis emphasized the vigorous genome-wide divergence of X. fastidiosa and detected three clonal groups of strains that cause Pierce’s disease (PD) of grapevine, citrus variegated chlorosis (CVC), and mulberry leaf scorch (MLS). Analysis of 16S rDNA sequences also identified the …

Relationship Between Secondary Metabolism And Fungal Development, Ana M. Calvo, Richard A. Wilson, Jin Woo Bok, Nancy P. Keller

Fungal Molecular Plant-Microbe Interactions

Details findings related to the relationship between secondary metabolism and fungal development.

Uses Of Antimicrobials In Plant Agriculture, Anne K. Vidaver

Department of Plant Pathology: Faculty Publications

Bacterial diseases of plants are less prevalent than diseases caused by fungi and viruses. Antimicrobials for prophylactic treatment of bacterial diseases of plants are limited in availability, use, and efficacy, and therapeutic use is largely ineffective. Most applications are by spray treatments in orchards. Monitoring and surveillance for drug resistance are not routinely done. In the United States, data on use of antimicrobials for treatment of bacterial diseases of plants are limited to streptomycin and oxytetracycline. Resistance to streptomycin has become widespread among bacterial phytopathogens; no resistance among these bacteria has yet been reported for oxytetracycline. No human health effects …

Isolation And Characterization Of Endophytic Colonizing Bacteria From Agronomic Crops And Prairie Plants, Denise K. Zinniel, Patricia A. Lambrecht, N. Beth Harris, Zhengyu Feng, Daniel Kuczmarski, Phyllis Higley, Carol A. Ishimaru, Alahari Arunakumari, Raul G. Barletta, Anne K. Vidaver

Department of Plant Pathology: Faculty Publications

Endophytic bacteria reside within plant hosts without causing disease symptoms. In this study, 853 endophytic strains were isolated from aerial tissues of four agronomic crop species and 27 prairie plant species. We determined several phenotypic properties and found approximately equal numbers of gram-negative and gram-positive isolates. In a greenhouse study, 28 of 86 prairie plant endophytes were found to colonize their original hosts at 42 days postinoculation at levels of 3.5 to 7.7 log₁₀ CFU/g (fresh weight). More comprehensive colonization studies were conducted with 373 corn and sorghum endophytes. In growth room studies, none of the isolates displayed pathogenicity, …

Proceedings Of The 27th Annual Meeting, Southern Soybean Disease Workers (April 6-8, 2000, Fort Walton Beach Florida), John S. Russin, Stephen R. Koenning, Raymond W. Schneider, Peggy S. King

Southern Soybean Disease Workers: Conference Proceedings

Contents

Southern United States Soybean Disease Loss Estimate for 1999. Compiled by SR Koenning

Treasury report. Peggy S King

Invited presentation

Bean Pod Mottle: A Soybean Disease on the Rise in the New Millennium. SA Ghabrial

Contributed papers

Response of Selected Mid-South Soybean Varieties to the Reniform Nematode. GW Lawrence, KS McLean, and SM Baird

Field Response of Soybean Cultivars to the Reniform Nematode Rotylenchulus reniformis. PS King, DB Weaver, and R Rodriguez-Kabana

Approaches to Race Determination in Soybean Cyst Nematode. AJ Palmateer, ME Schmidt, SR Stetina, and JS Russin

Nematological Survey of Selected Soybean and Cotton Fields in …

Characterization Of The Aspergillus Nidulans 14-3-3 Homologue, Arta, Peter R. Kraus, Amy F. Hoffman, Steven D. Harris

Department of Plant Pathology: Faculty Publications

The 14-3-3 family of proteins function as small adaptors that facilitate a diverse array of cellular processes by mediating specific protein interactions. One such process is the DNA damage checkpoint, where these proteins prevent inappropriate activation of cyclin-dependent kinases. The filamentous fungus Aspergillus nidulans possesses a highly conserved 14- 3-3 homologue (artA) that may function in an analogous manner to prevent septum formation. However, instead of blocking septation, over-expression of artA causes a severe delay in the polarization of conidiospores. This observation suggests that these proteins play an important role in hyphal morphogenesis.

The Shca Protein Is A Molecular Chaperone That Assists In The Secretion Of The Hoppsya Effector From The Type Iii (Hrp) Protein Secretion System Of Pseudomonas Syringae, Karin V. Van Dijk, Vincent C. Tam, Angela R. Records, Tanja Petnicki-Ocwieja, James R. Alfano

Center for Plant Science Innovation: Faculty Publications

Pseudomonas syringae uses a type III protein secretion system encoded by the Hrp pathogenicity island (Pai) to translocate effector proteins into plant cells. One of these effector proteins is HopPsyA. A small open reading frame (ORF), named shcA, precedes the hopPsyA gene in the Hrp Pai of P. s. syringae 61. The predicted amino acid sequence of shcA shares general characteristics with chaperones used in type III protein secretion systems of animal pathogens. A functionally non-polar deletion of shcA in P. s. syringae 61 resulted in the loss of detectable HopPsyA in supernatant fractions, consistent with ShcA acting as a …

Crop Updates 2002 - Geraldton, Steve Penny Jr, Robin Wilson, Iian Barclay, Robyn Mclean, Robert Loughman, Jenny Garlinge, Bill Lambe, Neil Venn, Peter Clarke, Wal Anderson, Raffaele De Cima, James Bee, Darshan Sharma, Sheena Lyon, Melaine Kupsch, Mohammad Amjad, Pam Burgess, Veronika Reck, Brenda Shackley, Ray Tugwell, Bindi Webb, Robert Park, Daya Patabendige, Phil Michael, Debbie Thackray, Jenny Hawkes, Roger Jones, David Stephens, Bob French, Laurie Wahlsten, Glen Riethmuller, M. Bolland, P. White, T. Khan, Kevin Walden, Ravjit Khangura, Martin J. Barbetti, Graham Walton, Françoise Berlandier, Paul Carmody, Christiaan Valentine, Roy Latter, Keith Devenish, Bill Bowden, Michael O'Connell, Chris Gazey, David Gartner, Caroline Peek, David Rogers, Greg Shea, George Yan, Alexandra Douglas, Sally Peltzer, Paul Matson, David Minkey, Clinton Revell, Giles Glasson, Dean Thomas, Aik Cheam, Siew Lee, Mike Clarke, Peter Newman, Glenn Adam

Crop Updates

This session covers twenty seven papers from different authors:

1. Taking the Why out of Wyalkatchem – the new widely adapted wheat variety, Steve Penny Jr, Department of Agriculture

2. Future wheat varieties, Robin Wilson, Iain Barclay,Robyn McLean, Robert Loughman, Jenny Garlinge, Bill Lambe, Neil Venn and Peter Clarke

Department of Agriculture

3. Maximising wheat variety performance through agronomic management, Wal Anderson, Raffaele Del Cima, James Bee, Darshan Sharma, Sheena Lyon, Melaine Kupsch, Mohammad Amjad, Pam Burgess, Veronika Reck, Brenda Shackley, Ray Tugwell, Bindi Webb and Steve Penny Jr

Department of Agriculture

4. Cereal rust update 2002 – …

Phylogenetic Relationships, Strain Diversity And Biogeography Of Tritimoviruses, Frank Rabenstein, Dallas L. Seifers, Jorg Schubert, Roy C. French, Drake C. Stenger

Department of Plant Pathology: Faculty Publications

North American and Eurasian isolates of Wheat streak mosaic virus (WSMV; genus Tritimovirus) and Oat necrotic mottle virus (ONMV; genus Rymovirus) were examined. Nine WSMV isolates differentially infected oat, barley, inbred maize line SDp2 and sorghum line KS56. The WSMV isolates clustered into groups based on phylogenetic analyses of the capsid protein (CP) cistron and flanking regions. WSMV isolates from the United States (US) and Turkey were closely related, suggesting recent movement between continents. Although more divergent, WSMV from Iran (WSMV-I) also shared a most recent common ancestor with the US and Turkish isolates. Another group of WSMV …

Crop Updates 2002 - Lupins, Amelia Mclarty, Bob French, Laurie Wahlsten, Martin Harries, Paul Blackwell, Mike Collins, Bill Crabtree, Geoff Fosbery, Angie Roe, Matt Beckett, Abul Hashem, Nerys Wilkins, Geoff Thomas, Ken Adcock, Debbie Thackray, Jenny Hawkes, Roger Jones, Brenda Coutts, Manisha Shankar, Mark Sweetingham, Bevan Buirchell, Nichole Burges, Dominie Wright, Susan J. Barker, Jairo A. Palta, Neil C. Turner, Matt Evans, Brett Glencross, John Curnow, Wayne Hawkins, Jon C. Clements

Crop Updates

This session covers twenty four papers from different authors:

LUPIN INDUSTRY ISSUES AND RESEARCH DIRECTIONS

ACKNOWLEDGMENTS Amelia McLarty LUPIN CONVENOR DEPARTMENT OF AGRICULTURE

VARIETIES

1. Evaluation of lupinus mutabilis in Western Australia, Bob French, Laurie Wahlsten and Martin Harries, Department of Agriculture

2. Adaption of restricted-branching lupins in short-growing season environments, Bob French, Laurie Wahlsten, Department of Agriculture

ESTABLISHMENT

3. Moisture delving for better lupin establishment, Dr Paul Blackwell, Department of Agriculture

4. Lupins, tramlines, 600mm rows, rolling and shield spraying … a good result in a dry season! Paul Blackwell and Mike Collins, Department of Agriculture

5. Lupin …

Crop Updates 2002 - Cereals, Peter Burgess, Gary Fawell, Dean A. Diepeveen, Tim Setter, Jeff Russell, Tony Seymour, Robin Wilson, Iain Barclay, Robyn Mclean, Robert Loughman, Jenny Garlinge, Bill Lambe, Neil Venn, Peter Clarke, Mohammad Amjad, Wal Anderson, Raffael Del Cima, James Bee, Darshen Sharma, Sheena Lyon, Melaine Kupsch, Pam Burges, Veronika Reck, Brenda Shackley, Ray Tugwell, Bindi Webb, Steve Penny Jr, James Fisher, Bill Bowden, Craig Scanlan, Senthold Asseng, Michael Robertson, M. A. Hamza, G. Mcconnell, W. K. Anderson, Md Shahajahan Miyan, Darshan Sharma, Daya Patabendige, Patrick Gethin, Stephen Loss, Tim O'Dea, Ryan Guthrie, Lisa Leaver, Tyrone Henning, Lionel Martin, Narelle Hill, Simon Wallwork, Laurence Carslake, Darren Hughes, Glen Mcdonald, Nichole Burges, Dominie Wright, Jenny Hawkes, Roger Jones, Kith Jayasena, Kazue Tanaka, Vanessa Johnson, Robert Loughman, Josh Jury, Sean Kelly, Shashi Sharma, Robert Park, Phil Michael, Debbie Thackray, Christopher Newman, Garren Knell, Kevin Povey, David Stephens

Crop Updates

This session covers thirty one papers from different authors:

VARIETIES AND BREEDING

1. Agronomic evaluation of wheat and barley in the central wheatbelt of Western Australia, Peter Burgess¹and Gary Fawell², ¹Agritech and ²Farmanco Management

2. Evaluating stress tolerance to terminal drought by Western Australian wheats, Dean Diepeveen and Dr Tim Setter, Department of Agriculture

3. Broadscale wheat variety comparisons featuring Wyalkatchem, Jeff Russell, Department of Agriculture

4. Australian crop accreditation system variety selector, Tony Seymour, Australian Crop Accreditation System

5. Future wheat varieties, Robin Wilson, Iain Barclay,Robyn McLean, Robert Loughman, …

Crop Updates 2002 - Oilseeds, David Eksteen, K. Neil Harker, George W. Clayton, Keith Downey, Keith Alcock, Kevin Walden, Beven Addison, Peter Carlton, Kevin Morthorpe, Stephen Addenbrooke, Alex Ford, S. Hasan Zaheer, G. Walton, Imma Farré, Paul Carmody, J. A. Fortescue, D. W. Turner, B. Tan, Margaret C. Campbell, Ian Pritchard, Richard W. Bell, K. Frost, Mike Wong, Ross Brennan, Roger Jones, Jenny Hawkes, Debbie Thackray, Moin U. Salam, Ravjit K. Khangura, Art J. Diggle, Martin Barbetti, Phil Michael, Françoise Berlandier, Christiaan Valentine, Greg Shea, Glen Riethmuller, Rafiul Alam, Greg Hamilton, Jo Hawksley, Patrick Smith, Paul Neve, Felicity Flugge, Amir Abadi, Stephen Powles, Brett Glencross, John Curnow, Wayne Hawkins

Crop Updates

This session covers twenty seven papers from different authors:

1. Forward and acknowledgements, Dave Eksteen, ACTING MANAGER OILSEEDS PRODUCTIVITY AND INDUSTRY DEVELOPMENT Department of Agriculture

PLENARY SESSION

2. GMO canola - Track record in Canada, K. Neil Harker and George W. Clayton,Agriculture and Agri-Food Canada, Lacombe Research Centre, Lacombe, Alberta, R. Keith Downey, Agriculture and Agri-Food Canada, Saskatoon Research Centre, Saskatoon, Saskatchewan

3. GMO canola – Prospects in Western Australia farming systems, Keith Alcock, Crop Improvement Institute, Department of Agriculture

4. Diamondback moth (DBM) in canola, Kevin Walden, Department of Agriculture

CANOLA AGRONOMY

5. Getting the best out of …

Crop Updates 2002 - Pulse Research And Industry Development In Western Australia, M. Harries, R. French, I. Pritchard, N. Brandon, N. Runciman, S. White, M. Seymour, P. White, J. Howieson, R. Yates, H. Dhammu, T. Piper, T. Khan, K. Regan, N. Suizu, D. Diepeveen, C. Veitch, J. Palta, A. Nandwal, N. Turner, H. Clarke, G. Dwyer, H. Loo, K. Siddique, M. Bellgard, M. Jones, Glen Riethmuller, B. Mcleod, R. Shackles, P. Smith, C. Francis, M. Bolland, M. Materne, J. Clements, C. Hanbury, R. Matic, M. Tate, B. Hughes, B. French, P. Rees, J. Galloway, M. Salam, A. Diggle, N. Burges, D. Wright, J. Hawkes, D. Thackray, R. Jones, O. Edwards, J. Ridsdill-Smith, R. Horbury, F. Berlandier, O. Byrne, D. Hardie, H. Sharma, M. De Sousa Majer, R. Roush, R. Morton, T. Higgins

Crop Updates

This session covers seventy one papers from different authors:

1. 2001 PULSE INDUSTRY HIGHLIGHTS

CONTRIBUTORS

BACKGROUND

2001 REGIONAL ROUNDUP

2. Northern Agricultural Region, M. Harries, Department of Agriculture

3. Central Agricultural Region, R. French and I. Pritchard, Department of Agriculture

4. Great Southern and Lakes, N. Brandon, N. Runciman and S. White, Department of Agriculture

5. Esperance Mallee, M. Seymour, Department of Agriculture

PULSE PRODUCTION AGRONOMY AND GENETIC IMPROVEMENT

6. Faba bean, P. White, Department of Agriculture

7. Germplasm evaluation, P. White, M. Seymour and M. Harries, Department of Agriculture

8. Variety evaluation, P. White, M. Harries, N. Brandon …

Crop Updates 2002 - Farming Systems, Peter Metcalfe, Mike Ewing, Roy Latta, Keith Devenish, Diana Fedorenko, Clayton Butterly, Chantelle Butterly, Kim Diamond, Neil Diamond, Stuart Mcalpine, Bill Bowden, Jessica Johns, Terry Piper, David Bowran, Robert Beard, Phil Ward, Dominie Wright, Nichole Burges, Roger Jones, Danae Harman, Greg Shea, George Yan, David Tennant, David Hall, Anyou Liu, Clinton Revell, Candy Hudson, Andrew Blake, Natalie Lauritsen, John Fosu-Nyarko, Roger Jones, Lisa Smith, Mike Jones, Geoff Dwyer, Bill Bowden, Michael O'Connell, Chris Gazey, David Gartner, Amanda Miller, Richard W. Bell, K. Frost, Mike Wong, Ross Brennan, N. J. Blake, G. Mconnell, D. Patabendige, N. Venn, Derk Bakker, Greg Hamilton, Dave Houlbrooke, Cliff Spann, Paul Blackwell, Bindi Webb, G. Lyle, K. Wittwer, Perry Dolling, Senthold Asseng, Ian Fillery, Michael Robertson, Caroline Peek, David Rogers, Peter Portman, Jeff Russell, Greg Shea, Ben Henderson, Ross Kingwell, Tresslyn Walmsley, Jean Galloway, Debbie Thackray, Moin Salam, Art Diggle, William J. Macleod, Jenny Hawkes

Crop Updates

This session covers forty one papers from different authors:

INTRODUCTION

1. Future Farming Systems session for Crop Updates 2002 Peter Metcalf, FARMING SYSTEMS SUBPROGRAM MANAGER GRAINS PROGRAM Department of Agriculture

2. Perennial pastures in annual cropping systems: Lucerne and beyond, the ‘Big Picture’, Mike Ewing, Deputy CEO CRC for Plant-based Management of Dryland Salinity, Department of Agriculture

3. Perennial pastures in annual cropping systems: lucerne and beyond, Roy Latta and Keith Devenish, Department of Agriculture

4. Establishing Lucerne with a cover crop, Diana Fedorenko¹, Clayton Butterly¹, Chantelle Butterly¹, Kim and Neil Diamond^{2 …}

Genomewide Identification Of Pseudomonas Syringae Pv.Tomato Dc3000 Promoters Controlled By The Hrpl Alternative Sigma Factor, Derrick E. Fouts, Robert B. Abramovitch, James R. Alfano, Angela M. Baldo, C. Robin Buell, Samuel Cartinhour, Arn K. Chatterjee, Mark D'Ascenzo, Michelle L. Gwinn, Sondra G. Lazarowitz, Na-Chun Lin, Gregory B. Martin, Amos H. Rehm, David J. Schneider, Karin V. Van Dijk, Xiaoyan Tang, Alan Collmer

Center for Plant Science Innovation: Faculty Publications

The ability of Pseudomonas syringae pv. tomato DC3000 to parasitize tomato and Arabidopsis thaliana depends on genes activated by the HrpL alternative sigma factor. To support various functional genomic analyses of DC3000, and specifically, to identify genes involved in pathogenesis, we developed a draft sequence of DC3000 and used an iterative process involving computational and gene expression techniques to identify virulence-implicated genes downstream of HrpLresponsive promoters. Hypersensitive response and pathogenicity (Hrp) promoters are known to control genes encoding the Hrp (type III protein secretion) machinery and a few type III effector proteins in DC3000. This process involved (i) identification of …

Functional Characterization And Localization Of The Aspergillus Nidulan Formin Sepa, Kathryn E. Sharpless, Steven D. Harris

Department of Plant Pathology: Faculty Publications

Formins are a family of multidomain scaffold proteins involved in actin-dependent morphogenetic events. In Aspergillus nidulans, the formin SEPA participates in two actin-mediated processes, septum formation and polarized growth. In this study, we use a new null mutant to demonstrate that SEPA is required for the formation of actin rings at septation sites. In addition, we find that a functional SEPA::GFP fusion protein localizes simultaneously to septation sites and hyphal tips, and that SEPA colocalizes with actin at each site. Using live imaging, we show that SEPA localization at septation sites and hyphal tips is dynamic. Notably, at septation …

Adenylyl Cyclase Functions Downstream Of The Gα Protein Gpa1 And Controls Mating And Pathogenicity Of Cryptococcus Neoformans, J. Andrew Alspaugh, Read Pukkila-Worley, Toshiaki Harashima, Lora M. Cavallo, Deanna L. Funnell, Gary M. Cox, John R. Perfect, James W. Kronstad, Joseph Heitman

Department of Plant Pathology: Faculty Publications

The signaling molecule cyclic AMP (cAMP) is a ubiquitous second messenger that enables cells to detect and respond to extracellular signals. cAMP is generated by the enzyme adenylyl cyclase, which is activated or inhibited by the Gα subunits of heterotrimeric G proteins in response to ligand-activated G-protein-coupled receptors. Here we identified the unique gene (CAC1) encoding adenylyl cyclase in the opportunistic fungal pathogen Cryptococcus neoformans. The CAC1 gene was disrupted by transformation and homologous recombination. In stark contrast to the situation for Saccharomyces cerevisiae, in which adenylyl cyclase is essential, C. neoformans cac1 mutant strains were viable and …

Mapping Of The P1 Proteinase Cleavage Site In The Polyprotein Of Wheat Streak Mosaic Virus (Genus Tritimovirus), Il-Ryong Choi, Kempton M. Horken, Drake C. Stenger, Roy C. French

Department of Plant Pathology: Faculty Publications

Monopartite members of the family Potyviridae utilize three virus-encoded proteinases to cleave the viral polyprotein into mature proteins. The amino-terminal region of the viral polyprotein is autolytically cleaved by the P1 proteinase. A domain required for P1 proteinase activity of Wheat streak mosaic virus (WSMV) was mapped using a series of templates with nested 3’-truncations or 5’-deletions to program in vitro transcription–translation reactions. The WSMV P1 proteinase cleavage site was mapped to a position downstream of amino acid residue 348 and upstream of amino acid residue 353, with the peptide bond between amino acid residues Y ₃₅₂ and G _{353 …}

Bean Pod Mottle Virus: A Threat To U.S. Soybean Production, Loren J. Giesler, Said A. Ghabrial, Thomas E. Hunt, John H. Hill

Department of Plant Pathology: Faculty Publications

Bean pod mottle virus (BPMV) is widespread in the major soybean-growing areas in the southern and southeastern United States. A severe outbreak of BPMV in the north central and northern Great Plains states is currently causing serious concern to soybean growers and to the soybean industry in this region (30). BPMV is efficiently transmitted in nature, within and between soybean fields, by several species of leaf-feeding beetles. The deleterious effects of BPMV infection not only reduce yield but also reduce seed quality, as seeds from infected plants may be discolored. Furthermore, BPMV predisposes soybeans to Phomopsis spp. seed infection (85), …

Isolation And Characterization Of A Virus That Infects Emiliania Huxleyi (Haptophyta), Tonje Castberg, Runar Thyrhaug, Aud Larsen, Ruth-Anne Sandaa, Mikal Heldal, James L. Van Etten, Gunnar Bratbak

Department of Plant Pathology: Faculty Publications

The isolation and characterization of a virus (designated EhV) that infects the marine coccolithophorid Emiliania huxleyi (Lohmann) Hay & Mohler are described. Three independent clones of EhV were isolated from Norwegian coastal waters in years 1999 and 2000. EhV is a double-stranded DNA-containing virus with a genome size of ~415 kilo-base pairs. The viral particle is an icosahedron with a diameter of 160–180 nm. The virus particle contains at least nine proteins ranging from 10 to 140 kDa; the major capsid protein weighs ~54 kDa. EhV has a latent period of 12–14 h and a burst size of 400–1,000 (mean, …

Characterization Of Wound-Inducible Genes Encoding Enzymes For Terpenoid Biosynthesis In Medicago Truncatula, Mandy M. Cox

Inquiry: The University of Arkansas Undergraduate Research Journal

In addition to having numerous applications as food flavorings and pharmaceuticals, terpenoids are an important class of defensive compounds that can accumulate in plants after pathogen infection or injury by insects. Sequences of DNA encoding putative terpene synthases and an oxidosqualene synthase, isolated from insect-damaged Medicago truncatula leaves, were selected from an expressed sequence tag (EST) database. The eDNA clones were used as radiolabeled probes to analyze gene expression in leaves treated with factors known to trigger a defense response in plants. Transcript levels for all of the genes examined increased in response to artificial wounding, insect herbivory, and methyl …

Endophyte Ergot Alkaloid Synthetic Compounds, Compounds Which Encode Therefor And Related Methods, Christopher L. Schardl, Jinhung Wang

Plant Pathology Faculty Patents

The present invention provides, inter alia, dmaW nucleic acid sequences and the proteins for which they encode. Also provided are methods for the utilization of knockout mutants of the sequences which are useful for engineering ergot alkaloid-deficient fungal symbionts (endophytes) of plants. Other methods and materials related to these sequences are also provided.

Selected Soybean Plant Introductions With Partial Resistance To Sclerotinia Sclerotiorum, D. D. Hoffman, B. W. Diers, G. L. Hartman, C. D. Nickell, R. L. Nelson, W. L. Pedersen, E. R. Cober, George L. Graef, J. R. Steadman, C. R. Grau, B. D. Nelson, L. E. Del Rio, T. Helms, T. Anderson, V. Poysa, University Of Guelph, W. C. Stienstra

Department of Plant Pathology: Faculty Publications

Sclerotinia stem rot, caused by Sclerotinia sclerotiorum, is a major soybean (Glycine max) disease in north-central regions of the United States and throughout the world. Current sources of resistance to Sclerotinia stem rot express partial resistance, and are limited in number within soybean germ plasm. A total of 6,520 maturity group (MG) 0 to IV plant introductions (PIs) were evaluated for Sclerotinia stem rot resistance in the United States and Canada in small plots or in the greenhouse from 1995 to 1997. Selected PIs with the most resistance were evaluated for resistance in the United States and …

Greenhouse And Field Evaluation Of Biological Control Of Fusarium Head Blight On Durum Wheat, D. A. Schisler, N. I. Khan, Michael J. Boehm, P. J. Slininger

Department of Plant Pathology: Faculty Publications

Fusarium head blight (FHB) is a devastating disease that causes extensive yield and quality losses to wheat and barley. In durum wheat, the pathogen-produced toxin deoxynivalenol (DON) is retained in semolina at ~50%, and the causal agent of FHB, Gibberella zeae, has a strong adverse effect on pasta color. Two bacteria and two yeast strains with known efficacy against G. zeae on hexaploid wheats were produced in liquid culture and assayed on two cultivars of durum wheat in greenhouse bioassays. All antagonists reduced FHB severity on cultivar Renville, and three of the four reduced severity on cultivar Ben, with …

Expression Patterns Of Novel Wound-Inducible Plant Genes In Medicago Truncatula, Mandy M. Cox, Kenneth L. Korth

Discovery, The Student Journal of Dale Bumpers College of Agricultural, Food and Life Sciences

Terpenoids are an important class of defensive compounds that can accumulate in plants after pathogen infection or injury by chewing insects. Clones encoding putative terpene synthases and an oxidosqualene synthase, isolated from insect-damaged Medicagotruncatula leaves, were selected from an expressed sequence tag (EST) database. The cDNA clones were used as radiolabeled probes to analyze gene expression in leaves treated by known factors that can trigger a defense response in plants. Transcript levels for all of the genes examined increased in response to artificial wounding, insect herbivory, and methyl jasmonate (meJA) treatments, whereas salicylic acid (SA) and glucose oxidase (GOX) had …

Genomewide Identification Of Proteins Secreted By The Hrp Type Iii Protein Secretion System Of Pseudomonas Syringae Pv. Tomato Dc3000, Tanja Petnicki-Ocwieja, David J. Schneider, Vincent C. Tam, Scott T. Chancey, Libo Shan, Yashitola Jamir, Lisa M. Schechter, Misty Janes, C. Robin Buell, Xiaoyan Tang, Alan Collmer, James R. Alfano

Department of Plant Pathology: Faculty Publications

The ability of Pseudomonas syringae pv. tomato DC3000 to be pathogenic on plants depends on the Hrp (hypersensitive response and pathogenicity) type III protein secretion system and the effector proteins it translocates into plant cells. Through iterative application of experimental and computational techniques, the DC3000 effector inventory has been substantially enlarged. Five homologs of known avirulence (Avr) proteins and five effector candidates, encoded by genes with putative Hrp promoters and signatures of horizontal acquisition, were demonstrated to be secreted in culture and/or translocated into Arabidopsis in a Hrp-dependent manner. These 10 Hrp-dependent outer proteins (Hops) were designated HopPtoC (Avr- PpiC2 …

The P23 Protein Of Citrus Tristeza Virus Controls Asymmetrical Rna Accumulation, Satyanarayana Tatineni, Siddarame Gowda, Maria A. Ayllon, Maria R. Albiach-Marti, Shailaja Rabindran, William O. Dawson

Department of Plant Pathology: Faculty Publications

Citrus tristeza virus (CTV), a member of the Closteroviridae, has a 19.3-kb positive-stranded RNA genome that is organized into 12 open reading frames (ORFs) with the 10 3' genes expressed via a nested set of nine or ten 3'-coterminal subgenomic mRNAs (sgRNAs). Relatively large amounts of negative-stranded RNAs complementary to both genomic and sgRNAs accumulate in infected cells. As is characteristic of RNA viruses, wild-type CTV produced more positive than negative strands, with the plus-to-minus ratios of genomic and sgRNAs estimated at 10 to 20:1 and 40 to 50:1, respectively. However, a mutant with all of the 3' genes …

The Short Term Effects Of A Fire Fighting Foam And Fire Retardant On Selected Flora From Australia's Southwest, Andrew B. Kennedy

Theses : Honours

Chemical fire suppressants arc used extensively throughout Australia's Southwest to contain and suppress wildfires. Despite several studies being conducted into their effects on terrestrial vegetation in North America and Eastern Australia, where a variety of significant effects were found, no such investigation has been carried out in Australia's Southwest. This study examined the short-term effects of a fire fighting foam and fire retardant on selected flora from Australia's Southwest. Various concentrations of fire fighting foam and fire retardant were applied to seeds and seedlings of several native species. Native species were chosen for their high abundance and widespread distribution throughout …