The Soybean Rhg1 Locus For Resistance To The Soybean Cyst Nematode Heterodera Glycines Regulates The Expression Of A Large Number Of Stress- And Defense-Related Genes In Degenerating Feeding Cells, 2011 University of Missouri
The Soybean Rhg1 Locus For Resistance To The Soybean Cyst Nematode Heterodera Glycines Regulates The Expression Of A Large Number Of Stress- And Defense-Related Genes In Degenerating Feeding Cells, Pramod Kaitheri Kandoth, Nagabhushana Ithal, Justin Recknor, Tom Maier, Dan Nettleton, Thomas J. Baum, Melissa G. Mitchum
Plant Pathology and Microbiology Publications
To gain new insights into the mechanism of soybean (Glycine max) resistance to the soybean cyst nematode (Heterodera glycines), we compared gene expression profiles of developing syncytia in soybean near-isogenic lines differing at Rhg1 (for resistance to Heterodera glycines), a major quantitative trait locus for resistance, by coupling laser capture microdissection with microarray analysis. Gene expression profiling revealed that 1,447 genes were differentially expressed between the two lines. Of these, 241 (16.8%) were stress- and defense-related genes. Several stress-related genes were up-regulated in the resistant line, including those encoding homologs of enzymes that lead to increased levels of ...
Recommendations For The Design Of Laboratory Studies On Non-Target Arthropods For Risk Assessment Of Genetically Engineered Plants, 2011 Agroscope Reckenholz-Tänikon Research Station ART
Recommendations For The Design Of Laboratory Studies On Non-Target Arthropods For Risk Assessment Of Genetically Engineered Plants, Jörg Romeis, Richard L. Hellmich, Marco P. Candolfi, Keri Carstens, Adinda De Schrijver, Angharad M. R. Gatehouse, Rod A. Herman, Joseph E. Huesing, Morven A. Mclean, Alan Raybould, Anthony M. Shelton, Annabel Waggoner
This paper provides recommendations on experimental design for early-tier laboratory studies used in risk assessments to evaluate potential adverse impacts of arthropod-resistant genetically engineered (GE) plants on non-target arthropods (NTAs). While we rely heavily on the currently used proteins from Bacillus thuringiensis (Bt) in this discussion, the concepts apply to other arthropod-active proteins. A risk may exist if the newly acquired trait of the GE plant has adverse effects on NTAs when they are exposed to the arthropod-active protein. Typically, the risk assessment follows a tiered approach that starts with laboratory studies under worst-case exposure conditions; such studies have a ...
Impact Of Cry3bb1-Expressing Bt Maize On Adults Of The Western Corn Rootworm, Diabrotica Virgifera Virgifera (Coleoptera: Chrysomelidae), 2011 Agroscope Reckenholz-Tanikon Research Station ART
Impact Of Cry3bb1-Expressing Bt Maize On Adults Of The Western Corn Rootworm, Diabrotica Virgifera Virgifera (Coleoptera: Chrysomelidae), Michael Meissle, Richard L. Hellmich, Jörg Romeis
Genetically engineered maize producing insecticidal Cry3Bb1 protein from Bacillus thuringiensis (Bt) is protected from root damage by corn rootworm larvae. An examination was made to establish whether western corn rootworm (Diabrotica virgifera virgifera) adults are affected by Cry3Bb1-expressing maize (MON88017) when feeding on above-ground tissue. In laboratory bioassays, adult D. v. virgifera were fed for 7 weeks with silk, leaves or pollen from Bt maize or the corresponding near-isoline. Male, but not female, survival was reduced in the Bt-leaf treatment compared with the control. Female weight was lower when fed Bt maize, and egg production was reduced in the Bt-silk ...
A Novel Class Of Miniature Inverted Repeat Transposable Elements (Mites) That Contain Hitchhiking (Gtcy)N Microsatellites, Brad S. Coates, J. A. Kroemer, Douglas V. Sumerford, Richard L. Hellmich
The movement of miniature inverted repeat transposable elements (MITEs) modifies genome structure and function. We describe the microsatellite-associated interspersed nuclear element 2 (MINE-2), that integrates at consensus WTTTT target sites, creates dinucleotide TT target site duplications (TSDs), and forms predicted MITE-like secondary structures; a 5' subterminal inverted repeat (SIR; AGGGTTCCGTAG) that is partially complementary to a 5' inverted repeat (IR; ACGAAGCCCT) and 3'-SIRs (TTACGGAACCCT). A (GTCY)(n) microsatellite is hitchhiking downstream of conserved 5'MINE-2 secondary structures, causing flanking sequence similarity amongst mobile microsatellite loci. Transfection of insect cell lines indicates that MITE-like secondary structures are sufficient to mediate ...
Delivery Of Prolamins To The Protein Storage Vacuole In Maize Aleurone Cells, 2011 University of Wisconsin
Delivery Of Prolamins To The Protein Storage Vacuole In Maize Aleurone Cells, Francisca C. Reyes, Taijoon Chung, David Holding, Rudolf Jung, Richard Vierstra, Marisa S. Otegui
Faculty Publications from the Center for Plant Science Innovation
Zeins, the prolamin storage proteins found in maize (Zea mays), accumulate in accretions called protein bodies inside the endoplasmic reticulum (ER) of starchy endosperm cells. We found that genes encoding zeins, a-globulin, and legumin-1 are transcribed not only in the starchy endosperm but also in aleurone cells. Unlike the starchy endosperm, aleurone cells accumulate these storage proteins inside protein storage vacuoles (PSVs) instead of the ER. Aleurone PSVs contain zeinrich protein inclusions, a matrix, and a large system of intravacuolar membranes. After being assembled in the ER, zeins are delivered to the aleurone PSVs in atypical prevacuolar compartments that seem ...
Plant Targets For Pseudomonas Syringae Type Iii Effectors: Virulence Targets Or Guarded Decoys?, 2011 University of Nebraska-Lincoln
Plant Targets For Pseudomonas Syringae Type Iii Effectors: Virulence Targets Or Guarded Decoys?, Anna Block, James R. Alfano
Faculty Publications from the Center for Plant Science Innovation
The phytopathogenic bacterium Pseudomonas syringae can suppress both pathogen-associated molecular pattern (PAMP)-triggered immunity (PTI) and effector-triggered immunity (ETI) by the injection of type III effector (T3E) proteins into host cells. T3Es achieve immune suppression using a variety of strategies including interference with immune receptor signaling, blocking RNA pathways and vesicle trafficking, and altering organelle function. T3Es can be recognized directly or indirectly by resistance proteins monitoring specific T3E targets resulting in ETI. It is presently unclear whether the monitored targets represent bona fide virulence targets or guarded decoys. Extensive overlap between PTI and ETI signaling suggests that T3Es may ...
The Novel Cyst Nematode Effector Protein 19c07 Interacts With The Arabidopsis Auxin Influx Transporter Lax3 To Control Feeding Site Development, Chris Lee, Demosthenis Chronis, Charlotte Kenning, Benjamin Peret, Tarek Hewezi, Eric L. Davis, Thomas J. Baum, Richard Hussey, Malcolm Bennett, Melissa G. Mitchum
Plant Pathology and Microbiology Publications
Plant-parasitic cyst nematodes penetrate plant roots and transform cells near the vasculature into specialized feeding sites called syncytia. Syncytia form by incorporating neighboring cells into a single fused cell by cell wall dissolution. This process is initiated via injection of esophageal gland cell effector proteins from the nematode stylet into the host cell. Once inside the cell, these proteins may interact with host proteins that regulate the phytohormone auxin, as cellular concentrations of auxin increase in developing syncytia. Soybean cyst nematode (Heterodera glycines) Hg19C07 is a novel effector protein expressed specifically in the dorsal gland cell during nematode parasitism. Here ...
Identification Of Potential Host Plant Mimics Of Clavata3/Esr (Cle)-Like Peptides From The Plant-Parasitic Nematode Heterodera Schachtii, Jianying Wang, Amy Replogle, Richard Hussey, Thomas Baum, Xiaohong Wang, Eric L. Davis, Melissa G. Mitchum
Plant Pathology and Microbiology Publications
In this article, we present the cloning of two CLAVATA3/ESR (CLE)-like genes, HsCLE1 and HsCLE2, from the beet cyst nematode Heterodera schachtii, a plant-parasitic cyst nematode with a relatively broad host range that includes the model plant Arabidopsis. CLEs are small secreted peptide ligands that play important roles in plant growth and development. By secreting peptide mimics of plant CLEs, the nematode can developmentally reprogramme root cells for the formation of unique feeding sites within host roots for its own benefit. Both HsCLE1 and HsCLE2 encode small secreted polypeptides with a conserved C-terminal CLE domain sharing highest similarity ...
Molecular And Chemical Dissection Of Cellulose Biosynthesis In Plants, 2011 University of Kentucky
Molecular And Chemical Dissection Of Cellulose Biosynthesis In Plants, Darby M. Harris
Theses and Dissertations--Plant and Soil Sciences
Plant cell walls are complex structures that must not only constrain cellular turgor pressure but also allow for structural modification during the dynamic processes of cell division and anisotropic expansion. Cell walls are composed of highly glycosylated proteins and polysaccharides, including pectin, hemicellulose and cellulose. The primary cell wall polysaccharide is cellulose, a polymer composed of high molecular weight !- 1,4-glucan chains. Although cellulose is the most abundant biopolymer on Earth, there is still a lot to learn about its biosynthesis and regulation. This research began by applying a variety of analytical techniques in an attempt to understand differences in ...
Comparative Genome Analysis Between Agrostis Stolonifera And Members Of The Pooideae Subfamily Including Brachypodium Distachyon, 2011 University of Massachusetts Amherst
Comparative Genome Analysis Between Agrostis Stolonifera And Members Of The Pooideae Subfamily Including Brachypodium Distachyon, Loreto P. Araneda
Masters Theses 1911 - February 2014
Understanding of grass genome structure and evolution has been significantly advanced through comparative genomics. The genomes of most cool-season forage and turf grasses, belonging to the Pooideae subfamily of the grasses, remain understudied. Creeping bentgrass (Agrostis stolonifera) is one of the most important cool-season turfgrasses due to its low mowing tolerance and aggressive growth habit. An RFLP genetic map of creeping bentgrass using 229 RFLP markers derived from cereal and creeping bentgrass EST-RFLP probes was constructed for a comparative genome analysis. This genetic map was compared with those of perennial ryegrass, oat, wheat, and rice. Large-scale chromosomal rearrangements between the ...
Phenotypic And Genotypic Diversity Of Eastern Leatherwood In Five Populations That Span Its Geographic Distribution, Bryan J. Peterson, William R. Graves, Jyotsna Sharma
Knowledge of variation among populations is important for making decisions about conservation of rare, threatened or endangered taxa. We investigated variation within and among five populations ofDirca palustris L. an understory shrub with a sporadic distribution and life-history traits that led us to predict strong phenotypic and genetic differentiation characteristic of historically limited gene flow. Populations sampled in Florida, Alabama, Illinois, Wisconsin and North Dakota spanned the geographic distribution of the species. Phenotypic traits differed among populations, and many traits correlated with latitude and environmental characteristics of the five sites. Principal components (PC) analysis showed that the first three ...
Genetic Structure And Gene Flow Among European Corn Borer Populations From The Great Plains To The Appalachians Of North America, Kyung Seok Kim, Brad S. Coates, Mark Bagley, Richard L. Hellmich, Thomas W. Sappington
1 Earlier population genetic spatial analysis of European corn borer Ostrinia nubilalis (Hubner) indicated no genetic differentiation even between locations separated by 720 km. This result suggests either high dispersal resulting in high gene flow or that populations are not in migration–drift equilibrium subsequent to their invasion of the central U.S.A. in the 1940s. 2 To discriminate among these two possibilities, samples were collected at 12 locations in eight states from New York to Colorado, a geographic scale that is three-fold greater than previously tested. Eight microsatellite markers were employed to estimate genetic differentiation and gene flow ...
Reverse-Genetic Analysis Of The Two Biotin-Containing Subunit Genes Of The Heteromeric Acetyl-Coenzyme A Carboxylase In Arabidopsis Indicates A Unidirectional Functional Redundancy, 2011 Iowa State University
Reverse-Genetic Analysis Of The Two Biotin-Containing Subunit Genes Of The Heteromeric Acetyl-Coenzyme A Carboxylase In Arabidopsis Indicates A Unidirectional Functional Redundancy, Xu Li, Hilal Ilarslan, Libuse Brachova, Hui-Rong Qian, Ling Li, Ping Che, Eve Syrkin Wurtele, Basil J. Nikolau
Genetics, Development and Cell Biology Publications
The heteromeric acetyl-coenzyme A carboxylase catalyzes the first and committed reaction of de novo fatty acid biosynthesis in plastids. This enzyme is composed of four subunits: biotin carboxyl-carrier protein (BCCP), biotin carboxylase, α-carboxyltransferase, and β-carboxyltransferase. With the exception of BCCP, single-copy genes encode these subunits in Arabidopsis (Arabidopsis thaliana). Reverse-genetic approaches were used to individually investigate the physiological significance of the two paralogous BCCP-coding genes, CAC1A (At5g16390, codes for BCCP1) and CAC1B (At5g15530, codes for BCCP2). Transfer DNA insertional alleles that completely eliminate the accumulation of BCCP2 have no perceptible effect on plant growth, development, and fatty acid accumulation. In ...
Fitness Cost Of Resistance To Bt Cotton Linked With Increased Gossypol Content In Pink Bollworm Larvae, 2011 University of Arizona
Fitness Cost Of Resistance To Bt Cotton Linked With Increased Gossypol Content In Pink Bollworm Larvae, Jennifer L. Williams, Christa Ellers-Kirk, Robert G. Orth, Aaron J. Gassmann, Graham Head, Bruce E. Tabashnik, Yves Carriere
Fitness costs of resistance to Bacillus thuringiensis (Bt) crops occur in the absence of Bt toxins, when individuals with resistance alleles are less fit than individuals without resistance alleles. As costs of Bt resistance are common, refuges of non-Bt host plants can delay resistance not only by providing susceptible individuals to mate with resistant individuals, but also by selecting against resistance. Because costs typically vary across host plants, refuges with host plants that magnify costs or make them less recessive could enhance resistance management. Limited understanding of the physiological mechanisms causing fitness costs, however, hampers attempts to increase costs. In ...
North American Continent - A New Source Of Wild Lactuca Spp. Germplasm Variability For Future Lettuce Breeding, A. Lebeda, I. Doležalová, M. Kitner, A. Novotná, P. Šmachová, M. P. Widrlechner
NCRPIS Conference Papers, Posters and Presentations
In the years 2002-2008, missions were undertaken in the USA and Canada to search for wild and weedy Lactuca species. Altogether, 16 states in the USA (Arizona, California, Colorado, Idaho, Iowa, Minnesota, Montana, Nevada, New York, North Carolina, Oregon, South Dakota, Utah, Washington, Wisconsin and Wyoming) and two provinces in Canada (Ontario and Quebec) were visited. In total, seven wild and weedy Lactuca spp. (L. serriola, L. saligna, L. virosa, L. canadensis, L. biennis, L. floridana, and L. ludoviciana), an interspecific hybrid (L. canadensis × L. ludoviciana), and an undetermined Lactuca species were observed and collected in 200 locations. In this ...
Cyp99a3: Functional Identification Of A Diterpene Oxidase From The Momilactone Biosynthetic Gene Cluster In Rice, 2011 Iowa State University
Cyp99a3: Functional Identification Of A Diterpene Oxidase From The Momilactone Biosynthetic Gene Cluster In Rice, Qiang Wang, Matthew L. Hillwig, Reuben J. Peters
Biochemistry, Biophysics and Molecular Biology Publications
Rice (Oryza sativa) produces momilactone diterpenoids as both phytoalexins and allelochemicals. Strikingly, the rice genome contains a biosynthetic gene cluster for momilactone production, located on rice chromosome 4, which contains two cytochromes P450 mono-oxygenases, CYP99A2 and CYP99A3, with undefined roles; although it has been previously shown that RNAi double knock-down of this pair of closely related CYP reduced momilactone accumulation. Here we attempted biochemical characterization of CYP99A2 and CYP99A3, which ultimately was achieved by complete gene recoding, enabling functional recombinant expression in bacteria. With these synthetic gene constructs it was possible to demonstrate that, while CYP99A2 does not exhibit significant ...
Gene Expression Patterns Are Correlated With Genomic And Genic Structure In Soybean, 2011 Iowa State University
Gene Expression Patterns Are Correlated With Genomic And Genic Structure In Soybean, Jenna L. Woody, Andrew J. Severin, Yung-Tsi Bolon, Bindu Joseph, Brian W. Diers, Andrew D. Farmer, Nathan Weeks, Gary J. Muehlbauer, Rex T. Nelson, David Grant, James E. Specht, Michelle A. Graham, Steven B. Cannon, Gregory D. May, Carroll P. Vance, Randy C. Shoemaker
Studies have indicated that exon and intron size and intergenic distance are correlated with gene expression levels and expression breadth. Previous reports on these correlations in plants and animals have been conflicting. In this study, next-generation sequence data, which has been shown to be more sensitive than previous expression profiling technologies, were generated and analyzed from 14 tissues. Our results revealed a novel dichotomy. At the low expression level, an increase in expression breadth correlated with an increase in transcript size because of an increase in the number of exons and introns. No significant changes in intron or exon sizes ...
The Evolution Of Sexual Reproduction In Cuscuta (Convolvulaceae), 2011 Wilfrid Laurier University
The Evolution Of Sexual Reproduction In Cuscuta (Convolvulaceae), Michael Wright
Theses and Dissertations (Comprehensive)
Cuscuta (Convolvulaceae), the dodders, is a genus of ca. 200 species of obligate stem parasites distributed across a great diversity of habitats worldwide. The existence of a handful of species that are dangerous crop weeds has led researchers to historically focus on their growth and control. Consequently, there is a dearth of information about their biodiversity, ecology, and in particular their reproductive biology. This thesis surveys aspects of sex allocation, floral evolution, floral rewards for pollinators, and mechanisms of reproductive assurance across the genus. I demonstrate that Cuscuta has evolved a broad spectrum of breeding systems, from obligate selfing to ...
Maize Transgenes Containing Zein Promoters Are Regulated By Opaque2, 2011 Iowa State University
Maize Transgenes Containing Zein Promoters Are Regulated By Opaque2, Megan N. Schroder, Brice E. Floyd, M. Paul Scott
Understanding epistatic interactions between transgenes and native genes is critical for predicting the response of transgenes to different genetic backgrounds and environments. Our objective was to determine if predicted epistatic interactions occur between maize (Zea mays L.) transgenes carrying zein promoters and opaque2, a transcriptional regulator of zein genes. Expression of the transgenes was significantly decreased in kernels containing the opaque2 mutation. Native zein proteins in these kernels were reduced as well. Thus, transgene expression mirrored expression of the native gene that contributed the promoter of the transgene. This work demonstrates that information about native gene expression may be useful ...
Resistant Starch And Starch Thermal Characteristics In Exotic Corn Lines Grown In Temperate And Tropical Environments, 2011 United States Department of Agriculture
Resistant Starch And Starch Thermal Characteristics In Exotic Corn Lines Grown In Temperate And Tropical Environments, Linda M. Pollak, M. Paul Scott, Susan A. Duvick
Corn as a food that is heated and cooled to allow starch retrogradation has higher levels of resistant starch (RS). Increasing the amount of RS can make corn an even healthier food and may be accomplished by breeding and selection, especially by using exotic germplasm. Sixty breeding lines of introgressed exotic germplasm backgrounds, selected for high yield, were grown in three tropical and temperate locations and analyzed for starch thermal characteristics and RS levels. Although actual values for all starch characteristics were within normal levels, most characteristics had significant genotypic effects, and all had significant location effects. Thermal properties of ...