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Full-Text Articles in Life Sciences

Mining Novel Effector Proteins From The Esophageal Gland Cells Of Meloidogyne Incognita, William B. Rutter, Tarek Hewezi, Sahar Abubucker, Tom R. Maier, Guozhong Huang, Makedonka Mitreva, Richard S. Hussey, Thomas J. Baum Sep 2014

Mining Novel Effector Proteins From The Esophageal Gland Cells Of Meloidogyne Incognita, William B. Rutter, Tarek Hewezi, Sahar Abubucker, Tom R. Maier, Guozhong Huang, Makedonka Mitreva, Richard S. Hussey, Thomas J. Baum

Plant Pathology and Microbiology Publications

Meloidogyne incognita is one of the most economically damaging plant pathogens in agriculture and horticulture. Identifying and characterizing the effector proteins which M. incognita secretes into its host plants during infection is an important step toward finding new ways to manage this pest. In this study, we have identified the cDNAs for 18 putative effectors (i.e., proteins that have the potential to facilitate M. incognita parasitism of host plants). These putative effectors are secretory proteins that do not contain transmembrane domains and whose genes are specifically expressed in the secretory gland cells of the nematode, indicating that they are ...


Effect Of Foliar Fungicides On Late-Season Anthracnose Stem Blight On Soybean, Nathan R. C. Bestor, Alison E. Robertson, Daren S. Mueller Aug 2014

Effect Of Foliar Fungicides On Late-Season Anthracnose Stem Blight On Soybean, Nathan R. C. Bestor, Alison E. Robertson, Daren S. Mueller

Plant Pathology and Microbiology Publications

Anthracnose stem blight, caused by Colletotrichum truncatum, is responsible for soybean (Glycine max) yield losses in subtropical and tropical growing regions. There are inadequate data regarding the effect of anthracnose stem blight on yield in Iowa, and it is unknown if fungicide application can manage this disease. Field studies were conducted from 2008 to 2010 to determine the effect of fungicide application timing on late-season development of this disease. We also investigated the effect of anthracnose stem blight on yield and specific yield components. Fungicides reduced late-season symptom development when compared to the untreated control; however, there were no differences ...


Members Of The Meloidogyne Avirulence Protein Family Contain Multiple Plant Ligand-Like Motifs, William B. Rutter, Tarek Hewezi, Tom R. Maier, Melissa G. Mitchum, Eric L. Davis, Richard S. Hussey, Thomas J. Baum Aug 2014

Members Of The Meloidogyne Avirulence Protein Family Contain Multiple Plant Ligand-Like Motifs, William B. Rutter, Tarek Hewezi, Tom R. Maier, Melissa G. Mitchum, Eric L. Davis, Richard S. Hussey, Thomas J. Baum

Plant Pathology and Microbiology Publications

Sedentary plant-parasitic nematodes engage in complex interactions with their host plants by secreting effector proteins. Some effectors of both root-knot nematodes (Meloidogynespp.) and cyst nematodes (Heterodera and Globodera spp.) mimic plant ligand proteins. Most prominently, cyst nematodes secrete effectors that mimic plant CLAVATA3/ESR-related (CLE) ligand proteins. However, only cyst nematodes have been shown to secrete such effectors and to utilize CLE ligand mimicry in their interactions with host plants. Here, we document the presence of ligand-like motifs in bona fide root-knot nematode effectors that are most similar to CLE peptides from plants and cyst nematodes. We have identified ...


Comparison Of Fumonisin Contamination Using Hplc And Elisa Methods In Bt And Near-Isogenic Maize Hybrids Infested With European Corn Borer Or Western Bean Cutworm, Erin Louise Bowers, Richard L. Hellmich, Gary P. Munkvold Jun 2014

Comparison Of Fumonisin Contamination Using Hplc And Elisa Methods In Bt And Near-Isogenic Maize Hybrids Infested With European Corn Borer Or Western Bean Cutworm, Erin Louise Bowers, Richard L. Hellmich, Gary P. Munkvold

Plant Pathology and Microbiology Publications

Field trials were conducted from 2007 to 2010 to compare grain fumonisin levels among non-Bt maize hybrids and Bt hybrids with transgenic protection against manual infestations of European corn borer (ECB) and Western bean cutworm (WBC). HPLC and ELISA were used to measure fumonisin levels. Results of the methods were highly correlated, but ELISA estimates were higher. Bt hybrids experienced less insect injury, Fusarium ear rot, and fumonisin contamination compared to non-Bt hybrids. WBC infestation increased fumonisin content compared to natural infestation in non-Bt and hybrids expressing Cry1Ab protein in five of eight possible comparisons; in Cry1F ...


Synchronization Of Developmental Processes And Defense Signaling By Growth Regulating Transcription Factors, Jinyi Liu, J. Hollis Rice, Nana Chen, Thomas J. Baum, Tarek Hewezi May 2014

Synchronization Of Developmental Processes And Defense Signaling By Growth Regulating Transcription Factors, Jinyi Liu, J. Hollis Rice, Nana Chen, Thomas J. Baum, Tarek Hewezi

Plant Pathology and Microbiology Publications

Growth regulating factors (GRFs) are a conserved class of transcription factor in seed plants. GRFs are involved in various aspects of tissue differentiation and organ development. The implication of GRFs in biotic stress response has also been recently reported, suggesting a role of these transcription factors in coordinating the interaction between developmental processes and defense dynamics. However, the molecular mechanisms by which GRFs mediate the overlaps between defense signaling and developmental pathways are elusive. Here, we report large scale identification of putative target candidates of Arabidopsis GRF1 and GRF3 by comparing mRNA profiles of the grf1/grf2/grf3 triple mutant ...


Pathotype And Genetic Shifts In A Population Of Phytophthora Sojae Under Soybean Cultivar Rotation, S. Stewart, N. Abeysekara, Alison E. Robertson May 2014

Pathotype And Genetic Shifts In A Population Of Phytophthora Sojae Under Soybean Cultivar Rotation, S. Stewart, N. Abeysekara, Alison E. Robertson

Plant Pathology and Microbiology Publications

Changes in pathotype structure of Phytophthora sojae populations have been attributed to deployment of race-specific resistant Rps genes in soybean that have been incorporated into commercial cultivars to reduce losses due to Phytophthora root and stem rot. To test this hypothesis, a cultivar rotation study was established from 2007 through 2010 in microplots at a site in Iowa with no history of soybean cultivation. All microplots were inoculated with P. sojae isolate PR1, race 1 (vir 7) prior to planting in year 1. Six rotations were tested: (i) continuous planting of a P. sojae-susceptible cultivar, (ii) continuous planting of ...


Geospatial And Temporal Analyses Of Bean Pod Mottle Virus Epidemics In Soybean At Three Spatial Scales, E. Byamukama, S. K. Eggenberger, R. A. Coelho-Netto, A. E. Robertson, F. W. Nutter Jr. Apr 2014

Geospatial And Temporal Analyses Of Bean Pod Mottle Virus Epidemics In Soybean At Three Spatial Scales, E. Byamukama, S. K. Eggenberger, R. A. Coelho-Netto, A. E. Robertson, F. W. Nutter Jr.

Plant Pathology and Microbiology Publications

A statewide survey was carried out from 2005 through 2007 to quantify, map, and analyze the spatial dynamics and seasonal patterns of Bean pod mottle virus (BPMV) prevalence and incidence within Iowa. In all, 8 to 16 soybean fields were arbitrarily sampled from 96 counties in 2005 and all 99 counties in 2006 and 2007. Field- and county-scale BPMV prevalence and incidence data were mapped using geographic information systems software. BPMV prevalence was highest in the 2006 soybean growing season, when BPMV was detected in 38.7% of all soybean fields, 91.9% of all counties, and 100% of the ...


Code-Assisted Discovery Of Tal Effector Targets In Bacterial Leaf Streak Of Rice Reveals Contrast With Bacterial Blight And A Novel Susceptibility Gene, Raul A. Cernadas, Erin L. Doyle, David O. Niño-Liu, Katherine E. Wilkins, Timothy J. Bancroft, Li Wang, Clarice L. Schmidt, Rico Caldo, Bing Yang, Frank F. White, Dan Nettleton, Roger P. Wise, Adam J. Bogdanove Feb 2014

Code-Assisted Discovery Of Tal Effector Targets In Bacterial Leaf Streak Of Rice Reveals Contrast With Bacterial Blight And A Novel Susceptibility Gene, Raul A. Cernadas, Erin L. Doyle, David O. Niño-Liu, Katherine E. Wilkins, Timothy J. Bancroft, Li Wang, Clarice L. Schmidt, Rico Caldo, Bing Yang, Frank F. White, Dan Nettleton, Roger P. Wise, Adam J. Bogdanove

Plant Pathology and Microbiology Publications

Bacterial leaf streak of rice, caused by Xanthomonas oryzae pv. oryzicola (Xoc) is an increasingly important yield constraint in this staple crop. A mesophyll colonizer, Xoc differs from X. oryzae pv. oryzae (Xoo), which invades xylem to cause bacterial blight of rice. Both produce multiple distinct TAL effectors, type III-delivered proteins that transactivate effector-specific host genes. A TAL effector finds its target(s) via a partially degenerate code whereby the modular effector amino acid sequence identifies nucleotide sequences to which the protein binds. Virulence contributions of some Xoo TAL effectors have been shown, and their relevant targets, susceptibility (S) genes ...


Flor Revisited (Again): Eqtl And Mutational Analysis Of Nb-Lrr Mediated Immunity To Powdery Mildew In Barley, Roger P. Wise, Priyanka Surana, Gregory S. Fuerst, Ruo Xu, Divya Mistry, Julie A. Dickerson, Dan Nettleton Dr. Feb 2014

Flor Revisited (Again): Eqtl And Mutational Analysis Of Nb-Lrr Mediated Immunity To Powdery Mildew In Barley, Roger P. Wise, Priyanka Surana, Gregory S. Fuerst, Ruo Xu, Divya Mistry, Julie A. Dickerson, Dan Nettleton Dr.

Plant Pathology and Microbiology Publications

Genes encoding early signaling events in pathogen defense often are identified only by their phenotype. Such genes involved in barley-powdery mildew interactions include Mla, specifying race-specific resistance; Rar1 (Required for Mla12-specified resistance1), and Rom1 (Restoration of Mla-specified resistance1). The HSP90-SGT1-RAR1 complex appears to function as chaperone in MLA-specified resistance, however, much remains to be discovered regarding the precise signaling underlying plant immunity. Genetic analyses of fast-neutron mutants derived from CI 16151 (Mla6) uncovered a novel locus, designated Rar3 (Required for Mla6-specified resistance3). Rar3 segregates independent of Mla6 and Rar1, and rar3 mutants are susceptible to Blumeria graminis f. sp. hordei ...


Mycotoxins That Affect The North American Agri-Food Sector: State Of The Art And Directions For The Future, J. D. Miller, A. W. Schaafsma, D. Bhatnagar, G. Bondy, I. Carbone, L. J. Harris, G. Harrison, Gary P. Munkvold, I. P. Oswald, J. J. Pestka, L. Sharpe, M. W. Sumarah, S. A. Tittlemier, T. Zhou Feb 2014

Mycotoxins That Affect The North American Agri-Food Sector: State Of The Art And Directions For The Future, J. D. Miller, A. W. Schaafsma, D. Bhatnagar, G. Bondy, I. Carbone, L. J. Harris, G. Harrison, Gary P. Munkvold, I. P. Oswald, J. J. Pestka, L. Sharpe, M. W. Sumarah, S. A. Tittlemier, T. Zhou

Plant Pathology and Microbiology Publications

This paper summarises workshop discussions at the 5th international MYCORED meeting in Ottawa, Canada (June 2012) with over 200 participants representing academics, government and industry scientists, government officials and farming organisations (present in roughly equal proportions) from 27 countries. Workshops centred on how mycotoxins in food and feed affect value chains and trade in the region covered by the North American Free Trade Agreement. Crops are contaminated by one or more of five important mycotoxins in parts of Canada and the United States every year, and when contaminated food and feed are consumed in amounts above tolerable limits, human ...


Distribution Of The Soybean Cyst Nematode, Heterodera Glycines, In The United States And Canada: 1954 To 2014, Gregory L. Tylka, Christopher C. Marett Jan 2014

Distribution Of The Soybean Cyst Nematode, Heterodera Glycines, In The United States And Canada: 1954 To 2014, Gregory L. Tylka, Christopher C. Marett

Plant Pathology and Microbiology Publications

The soybean cyst nematode, Heterodera glycines Ichinohe, is considered the most damaging pathogen of soybean (Glycine max (L.) Merr.) in the United States and Canada (6). This nematode also causes considerable yield loss in many other soybeanproducing countries in the world. Heterodera glycines was first discovered in the United States in New Hanover County, North Carolina in 1954 (5) and is believed to have been introduced from Asia (3). In 1987, the nematode was discovered in Kent County, Ontario (1). At various times since these initial discoveries, maps were created of the counties in the United States and Canada that ...


Substitution Of The Premembrane And Envelope Protein Genes Of Modoc Virus With The Homologous Sequences Of West Nile Virus Generates A Chimeric Virus That Replicates In Vertebrate But Not Mosquito Cells, Rungrat Saiyasombat, Jimena Carrillo-Tripp, W. Allen Miller, Peter J. Bredenbeek, Bradley J. Blitvich Jan 2014

Substitution Of The Premembrane And Envelope Protein Genes Of Modoc Virus With The Homologous Sequences Of West Nile Virus Generates A Chimeric Virus That Replicates In Vertebrate But Not Mosquito Cells, Rungrat Saiyasombat, Jimena Carrillo-Tripp, W. Allen Miller, Peter J. Bredenbeek, Bradley J. Blitvich

Plant Pathology and Microbiology Publications

Background: Most known flaviviruses, including West Nile virus (WNV), are maintained in natural transmission cycles between hematophagous arthropods and vertebrate hosts. Other flaviviruses such as Modoc virus (MODV) and Culex flavivirus (CxFV) have host ranges restricted to vertebrates and insects, respectively. The genetic elements that modulate the differential host ranges and transmission cycles of these viruses have not been identified. Methods: Fusion polymerase chain reaction (PCR) was used to replace the capsid (C), premembrane (prM) and envelope (E) genes and the prM-E genes of a full-length MODV infectious cDNA clone with the corresponding regions of WNV and CxFV. Fusion products ...


Fumonisins In Conventional And Transgenic, Insect-Resistant Maize Intended For Fuel Ethanol Production: Implications For Fermentation Efficiency And Ddgs Co-Product Quality, Erin Louise Bowers, Gary P. Munkvold Jan 2014

Fumonisins In Conventional And Transgenic, Insect-Resistant Maize Intended For Fuel Ethanol Production: Implications For Fermentation Efficiency And Ddgs Co-Product Quality, Erin Louise Bowers, Gary P. Munkvold

Plant Pathology and Microbiology Publications

Mycotoxins in maize grain intended for ethanol production are enriched in co-product dried distiller’s grains and solubles (DDGS) and may be detrimental to yeast in fermentation. This study was conducted to examine the magnitude of fumonisin enrichment in DDGS and to analyze the impacts of insect injury, Fusarium ear rot severity, and fumonisin contamination on final ethanol yield. Samples of naturally-contaminated grain (0 to 35 mg/kg fumonisins) from field trials conducted in 2008–2011 were fermented and DDGS collected and analyzed for fumonisin content. Ethanol yield (determined gravimetrically) was unaffected by fumonisins in the range occurring in this ...


Transcriptional Analysis Of The Global Regulatory Networks Active In Pseudomonas Syringae During Leaf Colonization, Xilan Yu, Steven P. Lund, Jessica W. Greenwald, Angela H. Records, Russell A. Scott, Dan Nettleton, Steven E. Lindow, Dennis C. Gross, Gwyn A. Beattie Jan 2014

Transcriptional Analysis Of The Global Regulatory Networks Active In Pseudomonas Syringae During Leaf Colonization, Xilan Yu, Steven P. Lund, Jessica W. Greenwald, Angela H. Records, Russell A. Scott, Dan Nettleton, Steven E. Lindow, Dennis C. Gross, Gwyn A. Beattie

Plant Pathology and Microbiology Publications

The plant pathogen Pseudomonas syringae pv. syringae B728a grows and survives on leaf surfaces and in the leaf apoplast of its host, bean (Phaseolus vulgaris). To understand the contribution of distinct regulators to B728a fitness and pathogenicity, we performed a transcriptome analysis of strain B728a and nine regulatory mutants recovered from the surfaces and interior of leaves and exposed to environmental stresses in culture. The quorum-sensing regulators AhlR and AefR influenced few genes in planta or in vitro. In contrast, GacS and a downstream regulator, SalA, formed a large regulatory network that included a branch that regulated diverse traits and ...


Identification Of Candidate Genes Involved In Early Iron Deficiency Chlorosis Signaling In Soybean (Glycine Max) Roots And Leaves, Adrienne N. Moran-Lauter, Gregory Allan Peiffer, Tengfei Yin, Steven A. Whitham, Dianne Cook, Randy Shoemaker, Michelle Graham Jan 2014

Identification Of Candidate Genes Involved In Early Iron Deficiency Chlorosis Signaling In Soybean (Glycine Max) Roots And Leaves, Adrienne N. Moran-Lauter, Gregory Allan Peiffer, Tengfei Yin, Steven A. Whitham, Dianne Cook, Randy Shoemaker, Michelle Graham

Plant Pathology and Microbiology Publications

Background

Iron is an essential micronutrient for all living things, required in plants for photosynthesis, respiration and metabolism. A lack of bioavailable iron in soil leads to iron deficiency chlorosis (IDC), causing a reduction in photosynthesis and interveinal yellowing of leaves. Soybeans (Glycine max (L.) Merr.) grown in high pH soils often suffer from IDC, resulting in substantial yield losses. Iron efficient soybean cultivars maintain photosynthesis and have higher yields under IDC-promoting conditions than inefficient cultivars.

Results

To capture signaling between roots and leaves and identify genes acting early in the iron efficient cultivar Clark, we conducted a RNA-Seq study ...


Replication Protein A Subunit 3 And The Iron Efficiency Response In Soybean, Sarah Atwood, Jamie A. O'Rourke, Tengfei Yin, Mahbubul Majumder, Chunquan Zhang, Sylvia R. Cianzio, John H. Hill, Dianne Cook, Steven A. Whitham, Randy Shoemaker, Michelle Graham Jan 2014

Replication Protein A Subunit 3 And The Iron Efficiency Response In Soybean, Sarah Atwood, Jamie A. O'Rourke, Tengfei Yin, Mahbubul Majumder, Chunquan Zhang, Sylvia R. Cianzio, John H. Hill, Dianne Cook, Steven A. Whitham, Randy Shoemaker, Michelle Graham

Plant Pathology and Microbiology Publications

In soybean [Glycine max (L.) Merr.], iron deficiency results in interveinal chlorosis and decreased photosynthetic capacity, leading to stunting and yield loss. In this study,gene expression analyses investigated the role of soybean replication proteinA (RPA) subunits during iron stress. Nine RPA homologs were significantly differentially expressed in response to iron stress in the near isogenic lines (NILs) Clark (iron efficient) and Isoclark (iron inefficient).RPAhomologs exhibited opposing expression patterns in the two NILs, with RPA expression significantly repressed during iron deficiency in Clark but induced in Isoclark. We used virus induced gene silencing (VIGS) to repress GmRPA3 expression in ...


The Haustorial Transcriptomes Of Uromyces Appendiculatus And Phakopsora Pachyrhizi And Their Candidate Effector Families, Tobias I. Link, Patrick Lang, Brian E. Scheffler, Mary V. Duke, Michelle A. Graham, Bret Cooper, Mark L. Tucker, Martjin Van De Mortel, Ralf T. Voegele, Kurt Mendgen, Thomas J. Baum, Steven A. Whitham Jan 2014

The Haustorial Transcriptomes Of Uromyces Appendiculatus And Phakopsora Pachyrhizi And Their Candidate Effector Families, Tobias I. Link, Patrick Lang, Brian E. Scheffler, Mary V. Duke, Michelle A. Graham, Bret Cooper, Mark L. Tucker, Martjin Van De Mortel, Ralf T. Voegele, Kurt Mendgen, Thomas J. Baum, Steven A. Whitham

Plant Pathology and Microbiology Publications

Haustoria of biotrophic rust fungi are responsible for the uptake of nutrients from their hosts and for the production of secreted proteins, known as effectors, which modulate the host immune system. The identification of the transcriptome of haustoria and an understanding of the functions of expressed genes therefore hold essential keys for the elucidation of fungus–plant interactions and the development of novel fungal control strategies. Here, we purified haustoria from infected leaves and used 454 sequencing to examine the haustorial transcriptomes of Phakopsora pachyrhizi and Uromyces appendiculatus, the causal agents of soybean rust and common bean rust, respectively. These ...