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Articles 61 - 90 of 1125

Full-Text Articles in Plant Pathology

Genetic And Biochemical Investigation Of Seed Fatty Acid Accumulation In Arabidopsis, Chinedu Charles Nwafor, Delin Li, Ping Qin, Long Li, Wei Zhang, Yuanwei Zhou, Jingjing Xu, Yongtai Yin, Jianbo Cao, Limin He, Fu Xiang, Chao Liu, Liang Guo, Yongming Zhou, Edgar B. Cahoon, Chunyu Zhang Jul 2022

Genetic And Biochemical Investigation Of Seed Fatty Acid Accumulation In Arabidopsis, Chinedu Charles Nwafor, Delin Li, Ping Qin, Long Li, Wei Zhang, Yuanwei Zhou, Jingjing Xu, Yongtai Yin, Jianbo Cao, Limin He, Fu Xiang, Chao Liu, Liang Guo, Yongming Zhou, Edgar B. Cahoon, Chunyu Zhang

Center for Plant Science Innovation: Faculty Publications

As a vegetable oil, consisting principally of triacylglycerols, is the major storage form of photosynthetically-fixed carbon in oilseeds which are of significant agricultural and industrial value. Photosynthesis in chlorophyll-containing green seeds, along with photosynthesis in leaves and other green organs, generates ATP and reductant (NADPH and NADH) needed for seed fatty acid production. However, contribution of seed photosynthesis to fatty acid accumulation in seeds have not been well-defined. Here, we report the contribution of seed-photosynthesis to fatty acid production by probing segregating green (photosynthetically-competent) and non-green or yellow (photosynthetically-non-competent) seeds in siliques of an Arabidopsis chlorophyll synthase mutant. Using this …


Insect Pest Management With Sex Pheromone Precursors From Engineered Oilseed Plants, Hong-Lei Wang, Bao-Jian Ding, Jian-Qing Dai, Tara J. Nazarenus, Rafael Borges, Agenor Mafra-Neto, Edgar B. Cahoon, Per Hofvander, Sten Stymne, Christer Löfstedt Jul 2022

Insect Pest Management With Sex Pheromone Precursors From Engineered Oilseed Plants, Hong-Lei Wang, Bao-Jian Ding, Jian-Qing Dai, Tara J. Nazarenus, Rafael Borges, Agenor Mafra-Neto, Edgar B. Cahoon, Per Hofvander, Sten Stymne, Christer Löfstedt

Center for Plant Science Innovation: Faculty Publications

Pheromones have become an environmentally friendly alternative to conventional insecticides for pest control. Most current pheromone-based pest control products target lepidopteran pests of high-value crops, as today’s manufacturing processes cannot yet produce pheromones at low enough costs to enable their use for lower-value crops, especially commodity crops. Camelina sativa seeds genetically modified to express (Z)-11-hexadecenoic acid, a sex pheromone precursor of several moth species, provided the oil from which the precursor was isolated, purified and transformed into the final pheromone. Trap lures containing this pheromone were then assessed for their capacity to manage moth pests in the field. Plant-derived pheromone …


The Pho1;2a'-M1.1 Allele Of Phosphate1 Conditions Misregulation Of The Phosphorus Starvation Response In Maize (Zea Mays Ssp. Mays L.), Ana Laura Alonso-Nieves, M. Nancy Salazar-Vidal, J. Vladimir Torres-Rodríguez, Leonardo M. Pérez-Vázquez, Julio A. Massange-Sánchez, C. Stewart Gillmor, Ruairidh J. H. Sawers Jun 2022

The Pho1;2a'-M1.1 Allele Of Phosphate1 Conditions Misregulation Of The Phosphorus Starvation Response In Maize (Zea Mays Ssp. Mays L.), Ana Laura Alonso-Nieves, M. Nancy Salazar-Vidal, J. Vladimir Torres-Rodríguez, Leonardo M. Pérez-Vázquez, Julio A. Massange-Sánchez, C. Stewart Gillmor, Ruairidh J. H. Sawers

Center for Plant Science Innovation: Faculty Publications

Plant PHO1 proteins play a central role in the translocation and sensing of inorganic phosphate. The maize (Zea mays ssp. mays) genome encodes two co-orthologs of the Arabidopsis PHO1 gene, designated ZmPho1;2a and ZmPho1;2b. Here, we report the characterization of the transposon footprint allele Zmpho1;2a'-m1.1, which we refer to hereafter as pho1;2a. The pho1;2a allele is a stable derivative formed by excision of an Activator transposable element from the ZmPho1;2a gene. The pho1;2a allele contains an 8-bp insertion at the point of transposon excision that disrupts the reading frame and is predicted to …


Divergent Evolution Of Extreme Production Of Variant Plant Monounsaturated Fatty Acids, Lu Gan, Kiyoul Park, Jin Chai, Evan M. Updike, Hyojin Kim, Adam Voshall, Sairam Behera, Xiao-Hong Yu, Yuanheng Cai, Chunyu Zhang, Mark A. Wilson, Jeffrey P. Mower, Etsuko Moriyama, Chi Zhang, Sireewan Kaewsuwan, Qun Liu, John Shanklin, Edgar B. Cahoon Jun 2022

Divergent Evolution Of Extreme Production Of Variant Plant Monounsaturated Fatty Acids, Lu Gan, Kiyoul Park, Jin Chai, Evan M. Updike, Hyojin Kim, Adam Voshall, Sairam Behera, Xiao-Hong Yu, Yuanheng Cai, Chunyu Zhang, Mark A. Wilson, Jeffrey P. Mower, Etsuko Moriyama, Chi Zhang, Sireewan Kaewsuwan, Qun Liu, John Shanklin, Edgar B. Cahoon

Center for Plant Science Innovation: Faculty Publications

Metabolic extremes provide opportunities to understand enzymatic and metabolic plasticity and biotechnological tools for novel biomaterial production. We discovered that seed oils of many Thunbergia species contain up to 92% of the unusual monounsaturated petroselinic acid (18:1Δ6), one of the highest reported levels for a single fatty acid in plants. Supporting the biosynthetic origin of petroselinic acid, we identified a Δ6-stearoyl-acyl carrier protein (18:0-ACP) desaturase from Thunbergia laurifolia, closely related to a previously identified Δ6-palmitoyl-ACP desaturase that produces sapienic acid (16:1Δ6)- rich oils in Thunbergia alata seeds. Guided by a T. laurifolia desaturase crystal structure obtained in this study, …


Plectus Of The Prairie: A Case Study Of Taxonomic Resolution From A Nematode Biodiversity Survey, Abigail Borgmeier, Kaitlin Gattoni, Timothy Harris, Rebecca Higgins, Peter Mullin, Dorota Porazinska, Kirsten S. Powers, David A. Wedin, Tom Powers May 2022

Plectus Of The Prairie: A Case Study Of Taxonomic Resolution From A Nematode Biodiversity Survey, Abigail Borgmeier, Kaitlin Gattoni, Timothy Harris, Rebecca Higgins, Peter Mullin, Dorota Porazinska, Kirsten S. Powers, David A. Wedin, Tom Powers

Department of Plant Pathology: Faculty Publications

Taxonomic resolution is a critical component of biodiversity assessments. In this case study, we examined a single taxon within a larger study of nematode diversity to evaluate the taxonomic resolution of different diversity assessment methods. The selected taxon was the microbial-feeding genus Plectus, a group considered to include multiple cosmopolitan species. The methods included a morphological evaluation by light microscopy, Sanger sequencing of PCR amplicons of COI and 18S gene regions, and 18S metabarcoding sequencing. The study sites were 15 remnant tallgrass prairie plots in eastern Nebraska. In the morphological analysis, we observed two basic morphotypes, a short-tailed form …


Association Mapping Across A Multitude Of Traits Collected In Diverse Environments In Maize, Ravi V. Mural, Guangchao Sun, Marcin Grzybowski, Michael C. Tross, Hongyu Jin, Christine Smith, Linsey Newton, Carson M. Andorf, Margaret R. Woodhouse, Addie M. Thompson, Brandi Sigmon, James C. Schnable May 2022

Association Mapping Across A Multitude Of Traits Collected In Diverse Environments In Maize, Ravi V. Mural, Guangchao Sun, Marcin Grzybowski, Michael C. Tross, Hongyu Jin, Christine Smith, Linsey Newton, Carson M. Andorf, Margaret R. Woodhouse, Addie M. Thompson, Brandi Sigmon, James C. Schnable

Center for Plant Science Innovation: Faculty Publications

Classical genetic studies have identified many cases of pleiotropy where mutations in individual genes alter many different phenotypes. Quantitative genetic studies of natural genetic variants frequently examine one or a few traits, limiting their potential to identify pleiotropic effects of natural genetic variants. Widely adopted community association panels have been employed by plant genetics communities to study the genetic basis of naturally occurring phenotypic variation in a wide range of traits. High-density genetic marker data—18M markers—from 2 partially overlapping maize association panels comprising 1,014 unique genotypes grown in field trials across at least 7 US states and scored for 162 …


Site-Specific Pest Management In Nebraska Corn And Soybean Production Systems, Zachary D. Rystrom May 2022

Site-Specific Pest Management In Nebraska Corn And Soybean Production Systems, Zachary D. Rystrom

Doctor of Plant Health Program: Dissertations and Student Research

Site-specific management (SSM) is widely used by farm producers to fertilize their fields. However, whole field management is currently practiced in integrated pest management (IPM). Site-specific management and agricultural technology can improve IPM especially when precision application of inputs can reduce selection pressure on pest populations, benefit the environment, or save costs of inputs. There is potential for site-specific pest management (SSPM) where pests, or environments vary spatially, and recommended management practices can be applied with precision. Three case studies are evaluated for SSPM to be applied in Nebraska corn and soybean production systems including corn rootworm, preemergence herbicides, and …


Two Magnaporthe Appressoria-Specific (Mas) Proteins, Momas3 And Momas5, Are Required For Suppressing Host Innate Immunity And Promoting Biotrophic Growth In Rice Cells, Ziwen Gong, Na Ning, Zhiqiang Li, Xin Xie, Richard Wilson, Wende Liu Apr 2022

Two Magnaporthe Appressoria-Specific (Mas) Proteins, Momas3 And Momas5, Are Required For Suppressing Host Innate Immunity And Promoting Biotrophic Growth In Rice Cells, Ziwen Gong, Na Ning, Zhiqiang Li, Xin Xie, Richard Wilson, Wende Liu

Department of Plant Pathology: Faculty Publications

In the devastating rice blast fungus Magnaporthe oryzae, six Magnaporthe appressoria-specific (MAS) proteins are encoded by MoGAS1, MoGAS2 and MoMAS3MoMAS6. MoGAS1 and MoGAS2 were previously characterized as M. oryzae virulence factors; however, the roles of the other four genes are unknown. Here, we found that, although the loss of any MAS gene did not affect appressorial formation or vegetative growth, ΔMomas3 and ΔMomas5 mutant strains (but not the others) were reduced in virulence on susceptible CO-39 rice seedlings. Focusing on ΔMomas3 and ΔMomas5 mutant strains, we found that they could penetrate …


Identification And Characterization Of Circular Rnas In Brassica Rapa In Response To Plasmodiophora Brassicae, Huishan Liu, Chinedu Charles Nwafor, Yinglan Piao, Xiaonan Li, Zongxiang Zhan, Zhongyun Piao Apr 2022

Identification And Characterization Of Circular Rnas In Brassica Rapa In Response To Plasmodiophora Brassicae, Huishan Liu, Chinedu Charles Nwafor, Yinglan Piao, Xiaonan Li, Zongxiang Zhan, Zhongyun Piao

Center for Plant Science Innovation: Faculty Publications

Plasmodiophora brassicae is a soil-borne pathogen that attacks the roots of cruciferous plants and causes clubroot disease. CircRNAs are noncoding RNAs, widely existing in plant and animal species. Although knowledge of circRNAs has been updated continuously and rapidly, information about circRNAs in the regulation of clubroot disease resistance is extremely limited in Brassica rapa. Here, Chinese cabbage (BJN 222) containing clubroot resistance genes (CRa) against P. brassicae Pb4 was susceptible to PbE. To investigate the mechanism of cicRNAs responsible for clubroot disease resistance in B. rapa, circRNA-seq was performed with roots of ‘BJN 222’ at 0, 8, and 23 days …


Expression Of Atwri1 And Atdgat1 During Soybean Embryo Development Influences Oil And Carbohydrate Metabolism, Cintia Lucía Arias, Truyen Quach, Tu Huynh, Hanh Nguyen, Ademar Moretti, Yu Shi, Ming Guo, Amira Rasoul, Kyujung Van, Leah Mchale, Thomas E. Clemente, Ana Paula Alonso, Chi Zhang Mar 2022

Expression Of Atwri1 And Atdgat1 During Soybean Embryo Development Influences Oil And Carbohydrate Metabolism, Cintia Lucía Arias, Truyen Quach, Tu Huynh, Hanh Nguyen, Ademar Moretti, Yu Shi, Ming Guo, Amira Rasoul, Kyujung Van, Leah Mchale, Thomas E. Clemente, Ana Paula Alonso, Chi Zhang

Center for Plant Science Innovation: Faculty Publications

Soybean oil is one of the most consumed vegetable oils worldwide. Genetic improvement of its concentration in seeds has been historically pursued due to its direct association with its market value. Engineering attempts aiming to increase soybean seed oil presented different degrees of success that varied with the genetic design and the specific variety considered. Understanding the embryo’s responses to the genetic modifications introduced, is a critical step to successful approaches. In this work, the metabolic and transcriptional responses to AtWRI1 and AtDGAT1 expression in soybean seeds were evaluated. AtWRI1 is a master regulator of fatty acid (FA) biosynthesis, and …


Ecology And Diversity Of Culturable Fungal Species Associated With Soybean Seedling Diseases In The Midwestern United States, Mirian F. Pimentel, Ali Y. Srour, Amanda J. Warner, Jason P. Bond, Carl A. Bradley, John Rupe, Martin I. Chilvers, J. Alejandro Rojas, Janette L. Jacobs, Christopher R. Little, Alison E. Robertson, Loren J. Giesler, Dean Malvick, Kiersten Wise, Albert Tenuta, Ahmad M. Fakhoury Feb 2022

Ecology And Diversity Of Culturable Fungal Species Associated With Soybean Seedling Diseases In The Midwestern United States, Mirian F. Pimentel, Ali Y. Srour, Amanda J. Warner, Jason P. Bond, Carl A. Bradley, John Rupe, Martin I. Chilvers, J. Alejandro Rojas, Janette L. Jacobs, Christopher R. Little, Alison E. Robertson, Loren J. Giesler, Dean Malvick, Kiersten Wise, Albert Tenuta, Ahmad M. Fakhoury

Department of Plant Pathology: Faculty Publications

Aims: To isolate and characterize fungi associated with diseased soybean seedlings in Midwestern soybean production fields and to determine the influence of environmental and edaphic factors on their incidence.

Methods and Results: Seedlings were collected from fields with seedling disease history in 2012 and 2013 for fungal isolation. Environmental and edaphic data associated with each field was collected. 3036 fungal isolates were obtained and assigned to 76 species. The most abundant genera recovered were Fusarium (73%) and Trichoderma (11.2%). Other genera included Mortierella, Clonostachys, Rhizoctonia, Alternaria, Mucor, Phoma, Macrophomina and Phomopsis. …


Improving Taxonomic Delimitation Of Fungal Species In The Age Of Genomics And Phenomics, Asjley Stengel, Kimberly M. Stanke, Amanda C. Quattrone, Joshua Herr Feb 2022

Improving Taxonomic Delimitation Of Fungal Species In The Age Of Genomics And Phenomics, Asjley Stengel, Kimberly M. Stanke, Amanda C. Quattrone, Joshua Herr

Department of Plant Pathology: Faculty Publications

Species concepts have long provided a source of debate among biologists. These lively debates have been important for reaching consensus on how to communicate across scientific disciplines and for advancing innovative strategies to study evolution, population biology, ecology, natural history, and disease epidemiology. Species concepts are also important for evaluating variability and diversity among communities, understanding biogeographical distributions, and identifying causal agents of disease across animal and plant hosts. While there have been many attempts to address the concept of species in the fungi, there are several concepts that have made taxonomic delimitation especially challenging. In this review we discuss …


The Astounding World Of Glycans From Giant Viruses, Anna Notaro, Chantal Abergel, Rosa Lanzetta, Todd L. Lowary, Antonio Molinaro, Michela Tonetti, James L. Van Etten, Cristina De Castro Feb 2022

The Astounding World Of Glycans From Giant Viruses, Anna Notaro, Chantal Abergel, Rosa Lanzetta, Todd L. Lowary, Antonio Molinaro, Michela Tonetti, James L. Van Etten, Cristina De Castro

Department of Plant Pathology: Faculty Publications

Viruses are a heterogeneous ensemble of entities, all sharing the need for a suitable host to replicate. They are extremely diverse, varying in morphology, size, nature, and complexity of their genomic content. Typically, viruses use host-encoded glycosyltransferases and glycosidases to add and remove sugar residues from their glycoproteins. Thus, the structure of the glycans on the viral proteins have, to date, typically been considered to mimick those of the host. However, the more recently discovered large and giant viruses differ from this paradigm. At least some of these viruses code for an (almost) autonomous glycosylation pathway. These viral genes include …


Fddm1 And Fddm2, Two Sgs3-Like Proteins, Function As A Complex To Affect Dna Methylation In Arabidopsis, Shengjun Li, Weilong Yang, Yunfeng Liu, Guangyong Li, Xiang Liu, Yaling Liu, James R. Alfano, Chi Zhang, Bin Yu Jan 2022

Fddm1 And Fddm2, Two Sgs3-Like Proteins, Function As A Complex To Affect Dna Methylation In Arabidopsis, Shengjun Li, Weilong Yang, Yunfeng Liu, Guangyong Li, Xiang Liu, Yaling Liu, James R. Alfano, Chi Zhang, Bin Yu

Center for Plant Science Innovation: Faculty Publications

DNA methylation is an important epigenetic modification required for the specific regulation of gene expression and the maintenance of genome stability in plants and animals. However, the mechanism of DNA demethylation remains largely unknown. Here, we show that two SGS3-like proteins, FACTOR OF DNA DEMETHYLATION 1 (FDDM1) and FDDM2, negatively affect the DNA methylation levels at ROS1-dependend DNA loci in Arabidopsis. FDDM1 binds dsRNAs with 50 overhangs through its XS (rice gene X and SGS3) domain and forms a heterodimer with FDDM2 through its XH (rice gene X Homology) domain. A lack of FDDM1 or FDDM2 increased DNA methylation levels …


Qteller: A Tool For Comparative Multi-Genomic Gene Expression Analysis, Margaret R. Woodhouse, Shatabdi Sen, David Schott, John L. Portwood Ii, Michael Freeling, Justin W. Walley, Carson M. Andorf, James Schnable Jan 2022

Qteller: A Tool For Comparative Multi-Genomic Gene Expression Analysis, Margaret R. Woodhouse, Shatabdi Sen, David Schott, John L. Portwood Ii, Michael Freeling, Justin W. Walley, Carson M. Andorf, James Schnable

Center for Plant Science Innovation: Faculty Publications

Motivation: Over the last decade, RNA-Seq whole-genome sequencing has become a widely used method for measuring and understanding transcriptome-level changes in gene expression. Since RNA-Seq is relatively inexpensive, it can be used on multiple genomes to evaluate gene expression across many different conditions, tissues and cell types. Although many tools exist to map and compare RNA-Seq at the genomics level, few web-based tools are dedicated to making data generated for individual genomic analysis accessible and reusable at a gene-level scale for comparative analysis between genes, across different genomes and meta-analyses. Results: To address this challenge, we revamped the comparative gene …


The Quest To Identify A New Virus Disease Of Sunflower From Nebraska, Robert M. Harveson, Maher Al Rwahnih, California Department Of Food And Agriculture, Alex Karasev, Tom J. Gulya, Jeff Bradshaw Jan 2022

The Quest To Identify A New Virus Disease Of Sunflower From Nebraska, Robert M. Harveson, Maher Al Rwahnih, California Department Of Food And Agriculture, Alex Karasev, Tom J. Gulya, Jeff Bradshaw

Panhandle Research and Extension Center

Between 2010 and 2018, sunflower plants exhibiting virus-like symptoms, including stunting, mottling, and chlorotic ringspots on leaves, were observed from commercial fields and research plots from four sites within three distinct counties of western Nebraska (Box Butte, Kimball, and Scotts Bluff). Near identical symptoms from field samples were reproduced on seedlings mechanically in the greenhouse on multiple occasions, confirming the presence of a sap-transmissible virus from each site. Symptomatic greenhouse-inoculated plants from the 2010 and 2011 Box Butte samples tested negative for sunflower mosaic virus (SuMV), sunflower chlorotic mottle virus (SuCMoV), and all potyviruses in general by ELISA and RT-PCR. …


Improving Taxonomic Delimitation Of Fungal Species In The Age Of Genomics And Phenomics, Ashley Stengel, Kimberly M. Stanke, Amanda C. Quattrone, Joshua R. Herr Jan 2022

Improving Taxonomic Delimitation Of Fungal Species In The Age Of Genomics And Phenomics, Ashley Stengel, Kimberly M. Stanke, Amanda C. Quattrone, Joshua R. Herr

Department of Plant Pathology: Faculty Publications

Species concepts have long provided a source of debate among biologists. These lively debates have been important for reaching consensus on how to communicate across scientific disciplines and for advancing innovative strategies to study evolution, population biology, ecology, natural history, and disease epidemiology. Species concepts are also important for evaluating variability and diversity among communities, understanding biogeographical distributions, and identifying causal agents of disease across animal and plant hosts. While there have been many attempts to address the concept of species in the fungi, there are several concepts that have made taxonomic delimitation especially challenging. In this review we discuss …


Determining The Novel Pathogen Neodothiora Populina As The Causal Agent Of The Aspen Running Canker Disease In Alaska, Loretta M. Winton, Gerard C. Adams, Roger W. Ruess Jan 2022

Determining The Novel Pathogen Neodothiora Populina As The Causal Agent Of The Aspen Running Canker Disease In Alaska, Loretta M. Winton, Gerard C. Adams, Roger W. Ruess

Department of Plant Pathology: Faculty Publications

Neodothiora populina Crous, G.C. Adams & Winton was determined to be a new pathogen of trembling aspen (Populus tremuloides) growing in Alaska, based on completion of Koch's Postulates in replicated forest and growth chamber inoculation trials. The pathogen is responsible for severe damage and widespread rapid mortality of sapling to mature aspen (≥ 80 years) in the boreal forests of interior Alaska, due to large diffuse annual (1–2 years) cankers. Isolation of the pathogen was challenging, and identification based on cultural characters was difficult. Fruiting bodies were not found on wild diseased trees, but erumpent pycnidia were found …


Ecological And Morphological Differentiation Among Coi Haplotype Groups In The Plant Parasitic Nematode Species Mesocriconema Xenoplax, Julianne N. Matczyszyn, Timothy Harris, Kirsten S. Powers, Sydney E. Everhart, Thomas O. Powers Dec 2021

Ecological And Morphological Differentiation Among Coi Haplotype Groups In The Plant Parasitic Nematode Species Mesocriconema Xenoplax, Julianne N. Matczyszyn, Timothy Harris, Kirsten S. Powers, Sydney E. Everhart, Thomas O. Powers

Department of Plant Pathology: Faculty Publications

DNA barcoding with the mitochondrial COI gene reveals distinct haplotype subgroups within the monophyletic and parthenogenetic nematode species, Mesocriconema xenoplax. Biological attributes of these haplotype groups (HG) have not been explored. An analysis of M. xenoplax from 40 North American sites representing both native plant communities and agroecosystems was conducted to identify possible subgroup associations with ecological, physiological, or geographic factors. A dataset of 132 M. xenoplax specimens was used to generate sequences of a 712 bp region of the cytochrome oxidase subunit I gene. Maximum-likelihood and Bayesian phylogenies recognized seven COI HG (≥99/0.99 posterior probability/bootstrap value). Species delimitation …


Ecological And Morphological Differentiation Among Coi Haplotype Groups In The Plant Parasitic Nematode Species Mesocriconema Xenoplax, Julianne N. Matczyszyn, Timothy Harris, Kirsten S. Powers, Sydney E. Everhart, Tom Powers Dec 2021

Ecological And Morphological Differentiation Among Coi Haplotype Groups In The Plant Parasitic Nematode Species Mesocriconema Xenoplax, Julianne N. Matczyszyn, Timothy Harris, Kirsten S. Powers, Sydney E. Everhart, Tom Powers

Department of Plant Pathology: Faculty Publications

DNA barcoding with the mitochondrial COI gene reveals distinct haplotype subgroups within the monophyletic and parthenogenetic nematode species, Mesocriconema xenoplax. Biological attributes of these haplotype groups (HG) have not been explored. An analysis of M. xenoplax from 40 North American sites representing both native plant communities and agroecosystems was conducted to identify possible subgroup associations with ecological, physiological, or geographic factors. A dataset of 132 M. xenoplax specimens was used to generate sequences of a 712 bp region of the cytochrome oxidase subunit I gene. Maximum-likelihood and Bayesian phylogenies recognized seven COI HG (≥99/0.99 posterior probability/bootstrap value). Species …


The Impact Of Beneficial Organisms In Corn Agroecosystems, Callie Rosalind Braley Dec 2021

The Impact Of Beneficial Organisms In Corn Agroecosystems, Callie Rosalind Braley

Doctor of Plant Health Program: Dissertations and Student Research

Corn is one of the world’s, and Nebraska’s, most important crops. Millions of acres are planted to corn each year in the Cornhusker State. However, each year there are a plethora of arthropod, weed, and microorganism pests that rob farmers of reaching their maximum yield potential. There are many options available to manage these pests in corn agroecosystems, but one option is often underutilized: beneficial organisms. For each pest, there are a variety of natural enemies that can assist in mitigating the damage caused by pests.

Many beneficial organisms exist, and they can be grouped by the type of pest …


Global Distribution And Richness Of Armillaria And Related Species Inferred From Public Databases And Amplicon Sequencing Datasets, Rachel A. Koch, Joshua Herr Nov 2021

Global Distribution And Richness Of Armillaria And Related Species Inferred From Public Databases And Amplicon Sequencing Datasets, Rachel A. Koch, Joshua Herr

Department of Plant Pathology: Faculty Publications

Armillaria is a globally distributed fungal genus most notably composed of economically important plant pathogens that are found predominantly in forest and agronomic systems. The genus sensulato has more recently received attention for its role in woody plant decomposition and in mycorrhizal symbiosis with specific plants. Previous phylogenetic analyses suggest that around 50 species are recognized globally. Despite this previous work, no studies have analyzed the global species richness and distribution of the genus using data derived from fungal community sequencing datasets or barcoding initiatives. To assess the global diversity and species richness of Armillaria, we mined publicly available sequencing …


Hyperspectral Reflectance-Based Phenotyping For Quantitative Genetics In Crops: Progress And Challenges, Marcin Grzybowski, Kuwan K. Wijewardane, Abbas Atefi, Yufeng Ge, James C. Schnable Oct 2021

Hyperspectral Reflectance-Based Phenotyping For Quantitative Genetics In Crops: Progress And Challenges, Marcin Grzybowski, Kuwan K. Wijewardane, Abbas Atefi, Yufeng Ge, James C. Schnable

Center for Plant Science Innovation: Faculty Publications

Many biochemical and physiological properties of plants that are of interest to breeders and geneticists have extremely low throughput and/or can only be measured destructively. This has limited the use of information on natural variation in nutrient and metabolite abundance, as well as photosynthetic capacity in quantitative genetic contexts where it is necessary to collect data from hundreds or thousands of plants. A number of recent studies have demonstrated the potential to estimate many of these traits from hyperspectral reflectance data, primarily in ecophysiological contexts. Here, we summarize recent advances in the use of hyperspectral reflectance data for plant phenotyping, …


Transcriptomics Reveals The Putative Mycoparasitic Strategy Of The Mushroom Entoloma Abortivum On Species Of The Mushroom Genus Armillaria, Rachel A. Koch, Joshua Herr Oct 2021

Transcriptomics Reveals The Putative Mycoparasitic Strategy Of The Mushroom Entoloma Abortivum On Species Of The Mushroom Genus Armillaria, Rachel A. Koch, Joshua Herr

Department of Plant Pathology: Faculty Publications

During mycoparasitism, a fungus—the host—is parasitized by another fungus—the mycoparasite. The genetic underpinnings of these relationships have been best characterized in ascomycete fungi. However, within basidiomycete fungi, there are rare instances of mushroom-forming species parasitizing the reproductive structures, or sporocarps, of other mushroom-forming species, which have been rarely investigated on a genetic level. One of the most enigmatic of these occurs between Entoloma abortivum and species of Armillaria, where hyphae of E. abortivum are hypothesized to disrupt the development of Armillaria sporocarps, resulting in the formation of carpophoroids. However, it remains unknown whether carpophoroids are the direct result of a …


A Phytobacterial Tir Domain Effector Manipulates Nad+ To Promote Virulence, Samuel Eastman, Thomas Smith, Mark A. Zaydman, Panya Kim, Samuel Martinez, Neha Damaraju, Aaron Diantonio, Jeffrey Milbrandt, Thomas E. Clemente, James R. Alfano, Ming Guo Sep 2021

A Phytobacterial Tir Domain Effector Manipulates Nad+ To Promote Virulence, Samuel Eastman, Thomas Smith, Mark A. Zaydman, Panya Kim, Samuel Martinez, Neha Damaraju, Aaron Diantonio, Jeffrey Milbrandt, Thomas E. Clemente, James R. Alfano, Ming Guo

Department of Plant Pathology: Faculty Publications

  • The Pseudomonas syringae DC3000 type III effector HopAM1 suppresses plant immunity and contains a Toll/interleukin-1 receptor (TIR) domain homologous to immunity-related TIR domains of plant nucleotide-binding leucine-rich repeat receptors that hydrolyze nicotinamide adenine dinucleotide (NAD+) and activate immunity. In vitro and in vivo assays were conducted to determine if HopAM1 hydrolyzes NAD+ and if the activity is essential for HopAM1’s suppression of plant immunity and contribution to virulence.
  • HPLC and LC-MS were utilized to analyze metabolites produced from NAD+ by HopAM1 in vitro and in both yeast and plants. Agrobacterium-mediated transient expression and in planta …


Nematode Biodiversity In Lincoln, Nebraska's Tallgrass Prairie Corridor, Abigail Borgmeier Aug 2021

Nematode Biodiversity In Lincoln, Nebraska's Tallgrass Prairie Corridor, Abigail Borgmeier

Department of Plant Pathology: Dissertations, Theses, and Student Research

The tallgrass prairie was once one of the most diverse grasslands on the planet, however over 95% has been converted to agriculture in the past 150 years. The remaining prairie is still host to a wide variety of plants, insects, mammals, and soil-dwelling microorganisms, creating an incredibly complex ecosystem. The first aim of this study is to compare three approaches for the measurement of nematode diversity within a 10-mile-long protected prairie habitat corridor near Lincoln, Nebraska. The methods are 1) a traditional morphological analysis of 150 nematodes per study site, 2) a metabarcoding analysis using the 18S genetic marker of …


The Importance Of Communication Skills To Independent Crop Consultants, Lindsay Overmyer Jul 2021

The Importance Of Communication Skills To Independent Crop Consultants, Lindsay Overmyer

Doctor of Plant Health Program: Dissertations and Student Research

Independent crop consulting companies provide services to farmers by scouting (i.e., collecting field observations of plants and pests) and developing management recommendations for individual fields. In production agriculture, independent crop consultants (ICCs) are professionals who are independent of product sales. They are knowledgeable in many disciplines including plant pathology, entomology, weed science, plant science, economics, water management, and soil science. However, ICCs must also have extensive communication skills to communicate to their audience of field scout(s), farmers, industry professionals, and government officials. The goal of this document is to examine how ICCs use their communication skills and how they can …


Toward Sustainable Production Of Value-Added Bioenergy And Industrial Oils In Oilseed And Biomass Feedstocks, Kiyoul Park, Sanju A. Sanjaya, Truyen Quach, Edgar B. Cahoon Jun 2021

Toward Sustainable Production Of Value-Added Bioenergy And Industrial Oils In Oilseed And Biomass Feedstocks, Kiyoul Park, Sanju A. Sanjaya, Truyen Quach, Edgar B. Cahoon

Center for Plant Science Innovation: Faculty Publications

Plant fatty acids are used forfood, feed, fuel, and industrial materials. Structurally and chemically diverse fatty acids, referred to as unusual or specialized fatty acids, are found in the seed oils of diverse plant species. Many unusual fatty acids have potential use as alternative and renewable sources of biofuels and biobased industrial feedstocks due to their variant structures' physical or functional properties. Oils enriched in these fatty acids can increase the value of oilseed crops and provide co-products that can be readily extracted from lignocellulosic materials in biomass crops. Here, we describe recent progress in strategies for enhancement of oil …


Disruption Of Long-Chain Base Hydroxylation Alters Growth And Impacts Sphingolipid Synthesis In Physcomitrella Patens, Abraham R. Steinberger, William Oscar Merino, Rebecca E. Cahoon, Edgar B. Cahoon, Daniel V. Lynch Jun 2021

Disruption Of Long-Chain Base Hydroxylation Alters Growth And Impacts Sphingolipid Synthesis In Physcomitrella Patens, Abraham R. Steinberger, William Oscar Merino, Rebecca E. Cahoon, Edgar B. Cahoon, Daniel V. Lynch

Center for Plant Science Innovation: Faculty Publications

Sphingolipids have roles as membrane structural components and as bioactive molecules in plants. In Physcomitrella patens, 4-hydroxysphinganine (phytosphingosine, t18:0) is the predominant sphingolipid long-chain base (LCB). To assess the functional significance of t18:0, CRISPR-Cas9 mutagenesis was used to generate mutant lines lacking the sole SPHINGOID BASE HYDROXYLASE (SBH) gene encoding the hydroxylase responsible for converting sphinganine (d18:0) to t18:0. Total sphingolipid content in sbh protonemata was 2.4-fold higher than in wild-type. Modest changes in glycosyl inositolphosphorylceramide (GIPC) glycosylation patterns occurred. Sphingolipidomic analyses of mutants lacking t18:0 indicated modest alterations in acyl-chain pairing with d18:0 in GIPCs and ceramides, but dramatic …


Meta-Analysis Identifies Pleiotropic Loci Controlling Phenotypic Trade-Offs In Sorghum, Ravi V. Mural, Marcin Grzybowski, Miao Chenyong, Alyssa Damke, Sirjan Sapkota, Richard E. Boyles, Maria G. Salas Fernandez, Patrick S. Schnable, Brandi Sigmon, Stephen Kresovich, James C. Schnable Jun 2021

Meta-Analysis Identifies Pleiotropic Loci Controlling Phenotypic Trade-Offs In Sorghum, Ravi V. Mural, Marcin Grzybowski, Miao Chenyong, Alyssa Damke, Sirjan Sapkota, Richard E. Boyles, Maria G. Salas Fernandez, Patrick S. Schnable, Brandi Sigmon, Stephen Kresovich, James C. Schnable

Department of Plant Pathology: Faculty Publications

Community association populations are composed of phenotypically and genetically diverse accessions. Once these populations are genotyped, the resulting marker data can be reused by different groups investigating the genetic basis of different traits. Because the same genotypes are observed and scored for a wide range of traits in different environments, these populations represent a unique resource to investigate pleiotropy. Here, we assembled a set of 234 separate trait datasets for the Sorghum Association Panel, a group of 406 sorghum genotypes widely employed by the sorghum genetics community. Comparison of genome-wide association studies (GWAS) conducted with two independently generated marker sets …