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9-Lipoxygenase Oxylipin Pathway in Plant Response to Biotic Stress

Description: The activity of plant 9-lipoxygenases (LOXs) influences the outcome of Arabidopsis thaliana interaction with pathogen and insects. Evidence provided here indicates that in Arabidopsis, 9-LOXs facilitate infestation by Myzus persicae, commonly known as the green peach aphid (GPA), a sap-sucking insect, and infection by the fungal pathogen Fusarium graminearum. in comparison to the wild-type plant, lox5 mutants, which are deficient in a 9-lipoxygenase, GPA population was smaller and the insect sp… more
Date: May 2012
Creator: Nalam, Vamsi J.
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries
open access

N-Acylethanolamine Metabolism During Seed Germination: Molecular Identification of a Functional N-Acylethanolamine Amidohydrolase

Description: N-Acylethanolamines (NAEs) are endogenous lipid metabolites that occur in a variety of dry seeds, and their levels decline rapidly during the first few hours of imbibition (Chapman et al., 1999, Plant Physiol., 120:1157-1164). Biochemical studies supported the existence of an NAE amidohydrolase activity in seeds and seedlings, and efforts were directed toward identification of DNA sequences encoding this enzyme. Mammalian tissues metabolize NAEs via an amidase enzyme designated fatty acid amid… more
Date: August 2004
Creator: Shrestha, Rhidaya
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries
open access

N-Acylethanolamine (NAE) Profiles Change During Arabidopsis Thaliana Seed Germination and Seedling Growth

Description: An understanding of the potential roles as lipid mediators of a family of bioactive metabolites called N-acylethanolamines (NAEs) depends on their accurate identification and quantification. The levels of 18C unsaturated NAEs (e.g. NAE18:2, NAE 18:3, etc.) in wild-type seeds (about 2000 ng/g fw) generally decreased by about 80% during germination and post-germinative growth. In addition, results suggest NAE-degradative fatty acid amide hydrolase (FAAH) expression does not play a major role in … more
Date: August 2006
Creator: Wiant, William C.
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries
open access

Alterations in Fatty Acid Amide Hydrolase (Faah) Transcript Levels and Activity Lead to Changes in the Abiotic Stress Susceptibility of Arabidopsis Thaliana

Description: N-Acylethanolamines (NAEs) are a class of bioactive lipids, and FAAH is one of the enzymes responsible for degrading NAEs in both plants and animals. in plants, FAAH appears to be closely associated with ABA, a phytohormone which has long been associated with plant stress responses, since the overexpression of FAAH in Arabidopsis results in ABA hypersensitivity. Therefore, it is reasonable to speculate that alterations in FAAH transcript levels will result in altered stress responses in plant… more
Date: May 2012
Creator: Gonzalez, Gabriel
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries
open access

Analysis of a Cotton Gene Cluster for the Antifungal Protein Osmotin

Description: Three overlapping genomic clones covering 29.0 kilobases of cotton DNA were found to encompass a cluster of two presumptive osmotin genes (OSMI and OSMII) and two osmotin pseudogenes (OSMIII and OSMIV). A segment of 16,007 basepairs of genomic DNA was sequenced from the overlapping genomic clones (GenBank Accessions AY303690 and AF304007). The two cotton osmotin genes were found to have open reading frames of 729 basepairs without any introns, and would encode presumptive osmotin preproteins o… more
Date: December 2003
Creator: Wilkinson, Jeffery Roland
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries
open access

Analysis of N-Acylethanolamines in the Oilseed Crop Camelina sativa

Description: To better understand the nature and function of N-acylethanolamines (NAEs) in Camelina sativa, we used mass spectrometry analysis to identify and quantify NAE types in developing seeds, desiccated seeds and seedlings. Developing seeds showed a differential increase in individual NAE species and an overall increase in NAE content with seed development and maturation. The NAE composition in mature, desiccated seeds mostly reflected the total fatty acid composition in the seed tissues, except fo… more
Date: August 2020
Creator: Corley, Chase D
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries
open access

Analysis of the Expression Profiles of Two Isoforms of the Antifungal Protein Osmotin from Gossypium hirsutum

Description: The expression of two cotton osmotin genes was evaluated in terms of the mRNA and protein expression patterns in response to chemical inducers such as ethylene, hydrogen peroxide, and sodium chloride. Reverse transcriptase-polymerase chain reactions (RT-PCR) indicated that osmotin mRNAs are expressed constitutively in root tissues of cotton plants, and that they are rapidly induced in leaf and stem tissues upon ethylene treatment. Real time RT-PCR indicated that osmotin transcript levels were… more
Date: May 2007
Creator: Spradling, Kimberly Diane
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries

Application of Cultured Neuronal Networks for Use as Biological Sensors in Water Toxicology and Lipid Signaling.

Description: This dissertation research explored the capabilities of neuronal networks grown on substrate integrated microelectrode arrays in vitro to be applied to toxicological research and lipid signaling. Chapter 1 details the effects of chlorine on neuronal network spontaneous electrical activity and pharmacological sensitivity. This study demonstrates that neuronal networks can maintain baseline spontaneous activity, and respond normally to pharmacological manipulations in the present of three times… more
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Date: August 2004
Creator: Dian, Emese Emöke
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries
open access

Bioaccumulation of Triclocarban, Triclosan, and Methyl-triclosan in a North Texas Wastewater Treatment Plant Receiving Stream and Effects of Triclosan on Algal Lipid Synthesis.

Description: Triclosan (TCS) and triclocarban (TCC), widely used antimicrobial agents found in numerous consumer products, are incompletely removed by wastewater treatment plant (WWTP) processing. Methyl-triclosan (M-TCS) is a more lipophilic metabolite of its parent compound, TCS. The focus of this study was to quantify bioaccumulation factors (BAFs) for TCS, M-TCS, and TCC in Pecan creek, the receiving stream for the City of Denton, Texas WWTP by using field samples mostly composed of the alga Cladophor… more
Date: August 2007
Creator: Coogan, Melinda Ann
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries

Characterization of cDNA and Genomic Clones for a Palmitoyl-acyl Carrier Protein Thioesterase and an Osmotin-Like PR5 Protein in Gossypium Hirsutum.

Description: Putative cotton cDNA clones and cognate genomic clones for a palmitoyl-acyl carrier protein (ACP) thioesterase (PATE) and an osmotin-like pathogenesis-related 5 (PR5) protein have been isolated and characterized. PATE is a class B fatty acid thioesterase with specificity for saturated long-chain fatty acids such as palmitate, and is implicated as a key enzyme to be targeted for regulation of fatty acid synthesis in order to alter cotton seed oil profiles. A nearly full-length 1.7-kb cDNA clon… more
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Date: May 2002
Creator: Yoder, David W.
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries
open access

Compartmentalization of Jojoba Seed Lipid Metabolites

Description: Seeds from the desert shrub Simmondsia chinensis (jojoba) are one of the only known natural plant sources to store a majority of its oil in the form of liquid wax esters (WE) instead of triacylglycerols (TAGs) and these oils account for ~55% of the seed weight. Jojoba oil is highly valued as cosmetic additives and mechanical lubricants, yet despite its value much is still unknown about its neutral lipid biosynthetic pathways and lipid droplet packaging machinery. Here, we have used a multi-"omi… more
Date: December 2018
Creator: Sturtevant, Drew
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries

Conformational Studies of Myosin and Actin with Calibrated Resonance Energy Transfer

Description: Resonance energy transfer was employed to study the conformational changes of actomyosin during ATP hydrolysis. To calibrate the technique, the parameters for resonance energy transfer were defined. With conformational searching algorithms to predict probe orientation, the distances measured by resonance energy transfer are highly consistent with the atomic models, which verified the accuracy and feasibility of resonance energy transfer for structural studies of proteins and oligonucleotides. … more
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Date: May 2000
Creator: Xu, Jin
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries

Developing a Generalizable Two-Input Genetic AND Logic Gate in Arabidopsis thaliana for Multi-Signal Processing

Description: With effective engineering using synthetic biology approaches, plant-based platforms could conceivably be designed to minimize the production costs and wastes of high-value products such as medicines, biofuels, and chemical feedstocks that would otherwise be uneconomical. Additionally, modern agricultural crops could be engineered to be more productive, resilient, or restorative in different or rapidly changing environments and climates. To achieve these complex goals, information-processing ge… more
Date: December 2022
Creator: Anderson, Charles Edgar
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries
open access

Development of Enabling Technologies to Visualize the Plant Lipidome

Description: Improvements in mass spectrometry (MS)-based strategies for characterizing the plant lipidome through quantitative and qualitative approaches such as shotgun lipidomics have substantially enhanced our understanding of the structural diversity and functional complexity of plant lipids. However, most of these approaches require chemical extractions that result in the loss of the original spatial context and cellular compartmentation for these compounds. To address this current limitation, severa… more
Date: August 2013
Creator: Horn, Patrick J.
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries
open access

Endocannabinoid System in a Planarian Model

Description: In this study, the presence and possible function of endocannabinoid ligands in the planarian is investigated. The endocannabinoids ananadamide (AEA) and 2-arachidonoylglycerol (2-AG) and entourage NAE compounds palmitoylethanolamide (PEA), stearoylethanolamide (SEA) and oleoylethanolamide (OEA) were found in Dugesia dorotocephala. Changes in SEA, PEA, and AEA levels were observed over the initial twelve hours of active regeneration. Exogenously applied AEA, 2-AG and their catabolic inhibition … more
Date: December 2010
Creator: Mustonen, Katie Lynn
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries
open access

Evaluation of Zinc Toxicity Using Neuronal Networks on Microelectrode Arrays: Response Quantification and Entry Pathway Analysis

Description: Murine neuronal networks, derived from embryonic frontal cortex (FC) tissue grown on microelectrode arrays, were used to investigate zinc toxicity at concentrations ranging from 20 to 2000 mM total zinc acetate added to the culture medium. Continual multi-channel recording of spontaneous action potential generation allowed a quantitative analysis of the temporal evolution of network spike activity generation at specific zinc acetate concentrations. Cultures responded with immediate concentratio… more
Date: August 2007
Creator: Parviz, Maryam
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries
open access

Expression analysis of the fatty acid desaturase 2-4 and 2-3 genes from Gossypium hirsutum in transformed yeast cells and transgenic Arabidopsis plants.

Description: Fatty acid desaturase 2 (FAD2) enzymes are phosphatidylcholine desaturases occurring as integral membrane proteins in the endoplasmic reticulum membrane and convert monounsaturated oleic acid into polyunsaturated linoleic acid. The major objective of this research was to study the expression and function of two cotton FAD2 genes (the FAD2-3 and FAD2-4 genes) and their possible role in plant sensitivity to environmental stress, since plants may increase the polyunsaturated phospholipids in mem… more
Date: August 2008
Creator: Zhang, Daiyuan
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries
open access

FLP-mediated conditional loss of an essential gene to facilitate complementation assays

Description: Commonly, when it is desirable to replace an essential gene with an allelic series of mutated genes, or genes with altered expression patterns, the complementing constructs are introduced into heterozygous plants, followed by the selection of homozygous null segregants. To overcome this laborious and time-consuming step, the newly developed two-component system utilizes a site-specific recombinase to excise a wild-type copy of the gene of interest from transformed tissues. In the first componen… more
Date: December 2007
Creator: Ganesan, Savita
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries
open access

Fluorescence labeling and computational analysis of the strut of myosin's 50 kDa cleft.

Description: In order to understand the structural changes in myosin S1, fluorescence polarization and computational dynamics simulations were used. Dynamics simulations on the S1 motor domain indicated that significant flexibility was present throughout the molecular model. The constrained opening versus closing of the 50 kDa cleft appeared to induce opposite directions of movement in the lever arm. A sequence called the "strut" which traverses the 50 kDa cleft and may play an important role in positioning… more
Date: August 2007
Creator: Gawalapu, Ravi Kumar
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries
open access

Genetic and Cellular Analysis of Anoxia-Induced Cell Cycle Arrest in Caenorhabditis elegans

Description: The soil-nematode Caenorhabditis elegans survives oxygen deprivation (anoxia < 0.001 kPa of O2, 0% O2) by entering into a state of suspended animation during which cell cycle progression at interphase, prophase and metaphase stage of mitosis is arrested. I conducted cell biological characterization of embryos exposed to various anoxia exposure times, to demonstrate the requirement and functional role of spindle checkpoint gene san-1 during brief anoxia exposure. I conducted a synthetic lethal s… more
Date: December 2008
Creator: Hajeri, Vinita A.
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries

Genetic Modification of Fatty Acid Profiles in Cotton

Description: The industrial uses of cottonseed oil are limited by its fatty acid composition. Genetic modification of cotton lipid profiles using seed-specific promoters could allow cotton growers to produce valuable new oils in the seed without adverse effects on fiber quality and yield, therefore making this crop more commercially profitable. Transgenic cotton callus harboring a diverged fatty acid desaturase gene (FADX) from Momordica charantia was characterized for production of alpha-eleostearic aci… more
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Date: August 2005
Creator: Rommel, Amy A.
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries
open access

Hindrance of the Myosin Power Stroke Posed by the Proximity to the Troponin Complex Identified Using a Novel LRET Fluorescent Nanocircuit

Description: A novel luminescence resonance energy transfer (LRET) nanocircuit assay involving a donor and two acceptors in tandem was developed to study the dynamic interaction of skeletal muscle contraction proteins. The donor transmits energy relayed to the acceptors distinguishing myosin subfragment-1 (S1) lever arm orientations. The last acceptor allows the detection of S1's bound near or in between troponin complexes on the thin filament. Additionally, calcium related changes between troponin T and my… more
Date: May 2007
Creator: Coffee Castro-Zena, Pilar G.
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries
open access

Identification and quantification of lipid metabolites in cotton fibers: Reconciliation with metabolic pathway predictions from DNA databases.

Description: The lipid composition of cotton (Gossypium hirsutum, L) fibers was determined. Fatty acid profiles revealed that linolenate and palmitate were the most abundant fatty acids present in fiber cells. Phosphatidylcholine was the predominant lipid class in fiber cells, while phosphatidylethanolamine, phosphatidylinositol and digalactosyldiacylglycerol were also prevalent. An unusually high amount of phosphatidic acid was observed in frozen cotton fibers. Phospholipase D activity assays revealed that… more
Date: May 2004
Creator: Wanjie, Sylvia W.
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries
open access

Influence of a Human Lipodystrophy Gene Homologue on Neutral Lipid Accumulation in Arabidopsis Leaves

Description: CGI-58 is the defective gene in the human neutral lipid storage disease called Chanarin-Dorfman syndrome. This disorder causes intracellular lipid droplets to accumulate in nonadipose tissues, such as skin and blood cells. Here, disruption of the homologous CGI-58 gene in Arabidopsis thaliana resulted in the accumulation of neutral lipid droplets in mature leaves. Mass spectroscopy of isolated lipid droplets from cgi-58 loss-of-function mutants showed they contain triacylglycerols with common l… more
Date: August 2016
Creator: James, Christopher Neal
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries
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