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Calmodulin Like 38 Is Required For Autophagy Of Hypoxia-Induced Cytoplasmic Rna Granules In Arabidopsis Thaliana, Sterling Field

Doctoral Dissertations

In response to the energy crisis resulting from submergence stress and hypoxia, the model plant Arabidopsis thaliana limits non-essential mRNA translation, and accumulates cytosolic stress granules. Stress granules are phase-separated mRNA-protein particles that partition transcripts for various fates: storage, degradation, or return to translation after stress alleviation. Another response by the plant cell to low oxygen stress is the induction of the turnover pathway autophagy. Stress granule regulation by autophagy occurs by a ‘granulophagy’ pathway in yeast and mammalian systems through which parts or whole stress granules are degraded. Whether this occurs in plants has not been investigated.

A connection …

A Systematic And Biogeographic Study Of Trillium (Melanthiaceae), Jayne A. Lampley

Doctoral Dissertations

Trillium (Melanthiaceae, Parideae) has a disjunct distribution occurring in eastern and western North America, and eastern Asia. Past studies have examined the phylogeny and historical biogeography of Melanthiaceae and Parideae, however these studies either did not fully examine these aspects within Trillium or did not employ sufficiently broad taxonomic or character sampling to clarify relationships among taxa. The first phylogenetic analysis presented in this study provides a resolved phylogeny for Trillium s.l. and Paris s.l. by using a dataset of 70 plastid coding genes and by sampling broadly from Trillium s.s., Pseudotrillium, Trillidium, Paris s.s., Daiswa, and Kinugasa. The results …

The Studies Of Effects Of Vitamin A Status On Type 2 Diabetes In Zucker Diabetic Fatty Rats And Retinoic Acid On Glucose Transporter 4 Expression In L6 Cells, Tiannan Wang

Doctoral Dissertations

The epidemic of metabolic diseases such as diabetes has become a public health concern. Previous research data from our lab have shown that vitamin A (VA) status and retinoic acid (RA), a metabolite of VA, contribute to the glucose and lipid metabolism in the body and cells. As the skeletal muscle contributes to metabolic homeostasis, the effects of VA signaling system on its glucose metabolism are worth to be investigated. Here in this dissertation, the following two projects were carried out to study the VA’s role in the control of metabolism. (1) The effects of VA status on the development …

Erecta Family Genes Regulate The Shoot Apical Meristem And Organ Formation, Daniel A. Degennaro

Doctoral Dissertations

Plants are sessile and must adjust their organ growth to their environments. A reservoir of stem cells in the shoot apical meristem (SAM) supplies cells for differentiation into organs. The SAM must balance organ production with stem cell maintenance. The ERECTA family (ERfs) encodes the leucine-rich repeat receptor-like kinases ERECTA (ER), ERECTA-LIKE 1 (ERL1), and ERL2. ERf signaling regulates organ initiation and stem cell maintenance. Results presented in this work include the following:

1) WUSCHEL (WUS) and CLAVATA3 (CLV3) make up a negative feedback loop to maintain SAM size. WUS and CLV3 expression localization is critical for …

Response Of Soil Viral And Microbial Functional Diversity To Long-Term Agricultural Management In Jackson, West Tennessee, Ning Duan

Doctoral Dissertations

Soil microbial communities are a critical component for ecosystem stability and function. Viruses, as an important biotic controller, have the potential to regulate the abundance and diversity of bacterial communities through infection. Soil is known to harbor abundant and diverse viral assemblages but their ecological role and influence on microbial processes has not been fully elucidated. Microbes can be influenced by viruses not only from infection but though biogeochemical feedbacks of the “microbial (bacterium–phage–DOC) loop” or “viral shunt”. However, we know relatively little about the microbial community and function under the regulation of viruses in soil and how they respond …

Geographic Patterns Of Genetic Diversity Under Climate Change: Linking Genes And Ecosystems, Shannon L. Bayliss

Doctoral Dissertations

Climate change is having profound effects on species distributions. However, much less is understood about how climate change may alter the distribution of genetic variation within species across landscapes. Maintaining genetic diversity within populations is essential for the survival of species in the face of rapid climatic changes, but importantly, losses of genetic variation will also have significant consequences on entire ecosystems. The objective of this dissertation is to understand how genetic variation in a riparian cottonwood species, Populus angustifolia, affects mass and energy exchange between the land and atmosphere across ~1700 km of latitude of the western United …

Microbial Community Dynamics Of A Microcystis Bloom, Helena Pound

Doctoral Dissertations

Harmful algal bloom events are notoriously associated with massive economic and environmental consequences, causing wildlife and human health risks. As these blooms increase in occurrence, duration, and severity around the world, it is essential to understand conditions leading to bloom formation and why they persist. Abiotic factors such as nutrients are commonly considered in bloom dynamics, but biotic interactions with co-occurring microbial species and viruses must also be taken into account. Harmful algal blooms dominated by the cyanobacterial genus Microcystis occur in bodies of water around the world and provide an ideal system in which to study top-down controls on …

Determining The Ecological And Physiological Factors Contributing To The Competitive Success Of Prochlorococcus In The Oligotrophic Ocean, Benjamin C. Calfee

Doctoral Dissertations

Prochlorococcus is a genus of extremely successful marine cyanobacteria. This success is realized through its pervasive biogeographical range and presence in almost all open ocean environments where it usually it the dominant phytoplankton. Limited capabilities of culturing and genetic manipulation of this organism have resulted in assumptions about this success overwhelmingly based on field observations. These studies have assumed adaptations for resource uptake and utilization in nutrient limited environments to cause dominance of Prochlorococcus over other photosynthetic microbes. In an attempt to definitively explain this through laboratory culture, we developed a culturing system to assay questions of nutrient limitation effects …

Perturbing Fatty Acid Metabolism In Enterococcus Faecalis Disrupts Responses To Exogenous Fatty Acids And The Antibiotic Daptomycin, Rachel D. Johnston

Doctoral Dissertations

Enterococcus faecalis is an opportunistic pathogen. In the host, it is exposed to fatty acids which impact cellular physiology and induce tolerance to the antibiotic daptomycin. To determine the requirements for induction of daptomycin tolerance, I examined the impacts of blocking de novo fatty acid synthesis or protein synthesis and removing cell wall. I observed that removal of the cell wall induced daptomycin tolerance, indicating that peptidoglycan is necessary for daptomycin to function. As specific exogenous fatty acids induce protection against daptomycin in E. faecalis, I also opted to examine whether incorporation of these free fatty acids was necessary …

High Arctic Permafrost Microbial Characterizations: Siberian And Svalbard Microbiology Of Ancient And Active Layer Permafrost, Katie Sipes

Doctoral Dissertations

Permafrost is soil that has remained frozen for at least two years. The active layer is a surface portion above the permafrost that experiences seasonal thaw and refreezing. The environmental characteristics of permafrost and active layer are different but are directly related to each other. As the climate continues to warm, the active layer will expand into the permafrost and the continuously frozen soil will be subjected to seasonal thawing. The organisms that inhabit both the active layer and the permafrost soil will respond differently to the climate based on where in the soil they are present and the soil …

Analytical Considerations And Methods For Comprehensive Analysis Of Bacterial Phospholipidomics Using Hilic-Ms/Ms, David Thomas Reeves

Doctoral Dissertations

Omics technologies have rapidly evolved over the last half century through vast improvements in efficient extraction methodologies, advances in instrumentation for data collection, and a wide assortment of informatics tools to help deconvolute sample data sets. However, there are still untapped pools of molecules that warrant further analytical attention. As the frontline defense of the cell against exterior influences, the phospholipid membrane is key in structure, defense, and signaling, but current omics studies are only just now catching up to the potential hidden within cellular lipid profiles. Examination of shifts in phospholipid speciation and character could provide researchers with a …

Porous Food Microparticles As Carriers Of Lipophilic Bioactive Compounds To Improve Functionalities, Inseob Choi

Doctoral Dissertations

Lipophilic bioactive compounds (LBCs) have been gaining attention due to their antioxidation and health-promotion properties. Although many delivery systems have been studied to encapsulate LBCs to increase stability and bioaccessibility of the LBCs, most of delivery systems lack of practicality for application in the food industry due to energy-extensive encapsulation processes and high-cost carrier materials used. Additionally, while a variety of encapsulating systems exist in nanoscale to achieve efficient encapsulation of LBCs, nanoscale systems with encapsulated LBCs may be subjected to reassessment of toxicity. In this dissertation, freeze-dried potato microparticles (FDPMs) and freeze-dried mushroom microparticles (FDMMs) were studied as carrier …

Effects Of N-3 Pufa-Derived Epoxides Combined With Seh Inhibition On Brown Adipose Tissue And Brown Adipocytes In Obesity, Yang Yang

Doctoral Dissertations

Brown adipose tissue (BAT) has become a promising target for obesity treatment and prevention. However, effective dietary factors to promote BAT mass and function have not been identified. 17,18-epoxyeicosatetraenoic acid (17,18-EEQ) and 19,20-epoxydocosapentaenoic acid (19,20-EDP) are two prominent epoxy fatty acids (EpFAs) produced from n-3 polyunsaturated fatty acid eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), respectively. EpFAs are quickly metabolized to less active diols by soluble epoxide hydrolase (sEH). In this dissertation, the effects of an sEH inhibitor (t-TUCB) (which stabilizes EpFAs) alone or combined with n-3 EpFAs on thermogenic activity in the BAT and brown adipocytes in …

Pollinator Community Homogenization And Pollination Services In Agroecosystems, Devon S. Eldridge .

Masters Theses

Pollination, or the transfer of pollen to plant stigmas, is an essential part of plant reproduction. The term “pollination system” refers to the floral phenotype and pollinator of a given plant. Although angiosperms exhibit a variety of different pollination systems, most rely partially or completely on animals, particularly insects, to vector their pollen. In agricultural systems, understanding the pollination system of the crop species is necessary to produce an economically valuable yield. Moreover, agricultural management may affect pollination systems by altering the abundance, diversity, or function of the pollinator community. In natural ecosystems, there is a great diversity of pollinating …

Impacts Of Anthropogenic Change On Plant Reproduction And Fitness, Alexandra S. Faidiga

Masters Theses

Humans are altering natural systems around the globe in myriad ways. For plant species, such anthropogenic changes have resulted in increasingly fragmented populations, desynchronized interactions with mutualists, and shifted geographic ranges, among other effects. However, despite numerous examples of human impacts on plant populations, the consequences of these changes on plant reproduction remain poorly understood. In my thesis, I investigate the impacts of two forms of anthropogenic change–habitat disturbance and climate warming–on plant reproduction and fitness. I take two distinct approaches to address questions posed at local and regional scales. In Chapter I, I ask how inbreeding depression varies across …

The Factors Influencing The Leader’S Perceptions Of Success Of Dairy Cooperatives: The Case Of Cumbal Nariño’S Dairy Associations, Omar Efren Aza Fuelantala

Masters Theses

During the last few decades, Colombia’s dairy sector has been affected by economic, social, and political conditions, not only endangering it but also putting at risk the long-term sustainability of the dairy industry. To mitigate these conditions, the dairy farmers have joined cooperatives, which enabled them to gain some strategic advantages and reduce the adverse effects of the economic, political, and social conditions. This study evaluates the influence of economic, financial, membership, management and operational characteristics on the presidents’ perceptions of success of the dairy associations in Cumbal-Nariño. To accomplish this objective, we surveyed the presidents of dairy associations in …

Modeling And Quality Analysis Of Radio Frequency Heating Of Low Moisture Foods, Qianyi Chen

Masters Theses

Low moisture food is usually considered as high safety food. Since its low water activity (aw < 7), this would be a strict environment for pathogen microbes to grow in the low moisture food. However, the recent outbreaks of Salmonella in low moisture foods indicated the possibility of microbiological contamination happened during the harvesting, processing or transportation of food products. Since the bad heat conduction of conventional thermal process on low moisture food, radiofrequency (RF) treatment is a promising technology to improve the heating efficiency with its volumetric heating. Nevertheless, non-uniformity heating is still a challenge in RF technology. There are two research chapters in this study. The first research chapter was to use computer modeling to understand the improvement of applied immersion fluids on the RF heating of the cornflour. The model had a good agreement with the experiment results. The modeling results showed that the soybean oil immersion could reduce the electric field distortion to get the best heating uniformity. Also, the higher sample heating rate caused by soybean oil immersion was mainly because of higher electromagnetic power absorption and lower surface heat loss. The heating efficiency of RF was improved but less study focused on the quality analysis of flour. Therefore, the second research study is to evaluate the effect of RF and extensive hot air oven processing on the quality and functionality of all-purposed flour.

Feeding Behavior And Influence Of Hemp Varieties And Fertilization Rates On Damage Caused By Corn Earworm, Helicoverpa Zea, Julian Cosner

Masters Theses

Production of industrial hemp, Cannabis sativa L., has increased tremendously in the U.S. after its legalization through the Agricultural Improvement Act of 2018, known as the 2018 Farm Bill, which allowed commercial hemp production. By grower number, in 2020, Tennessee was the nation’s largest hemp program with over 1,800 producers licensed to grow up to 6,500 hectares (16,000 acres) according to the Tennessee Department of Agriculture. Though fiber and seed have a role in the industry, most growers (ca. 98%) concentrate on cannabidiol production because of the expected higher cash value potential per hectare. Introducing hemp as a monocrop system …

Seasonality, Distribution, And Biological Control Of Crapemyrtle Bark Scale, A New Invasive Threat In Tennessee, Amira Cornish

Masters Theses

Crapemyrtle bark scale, Acanthococcus (= Eriococcus) lagerstroemiae (Kuwana), an invasive pest from Asia, is a threat in the United States. to crape myrtles grown in ornamental nurseries and in landscapes. Although mortality to crape myrtles is rare, its negative effects on aesthetics is considerable. It should affect the sale (valued at >$66 million wholesale) and use of crape myrtle in landscapes. This pest species has been found in numerous states, including Tennessee, where little is known about its state-wide distribution, lifecycle, biology, natural enemies, and impact on crape myrtles. The purpose of this two-year study is to gain additional knowledge …

Molecular Markers Within And Beyond Viburnum: A Single Set Of Ssrs For An Immense Genus, Trinity Paige Hamm

Masters Theses

Comprised of more than 160 species, Viburnum is the largest genus in the Viburnaceae (formerly Adoxaceae) alongside Adoxa and Sambucus. The native range of Viburnum species spans much of the Northern Hemisphere and extends into the mountains of South America and Southeastern Asia. Their wide geographic range has made Viburnum particularly interesting to phylogeographers and phylogeneticists. This diverse genus is also horticulturally valuable with varying traits such as fragrance, fruit color, and bud and inflorescence form. There is sufficient morphological diversity in the genus for there to be more than 70 species and intraspecific hybrids in cultivation, and in …

Regulation, Mechanism Of Action, And Function Of A Small Toxin Protein In Ehec, Bikash Bogati

Doctoral Dissertations

The zor-orz locus identified in the chromosome of Escherichia coli O157:H7 EDL933 is a type I toxin-antitoxin system that consists of two homologous gene pairs zorO-orzO and zorP-orzP. The zor genes encode for small toxin proteins and the orz genes encode for small RNAs. Previously it was shown that overproduction of ZorO results in cell growth stasis whereas co-expression of orzO rescues cellular growth. Within, I demonstrate that in addition to growth inhibition, ZorO overproduction results in membrane depolarization and ATP depletion but does not impact the gross morphology of E. coli. In vivo translation and subsequent impacts …

Influence Of Physical Variability Of Highly Weathered Sedimentary Rock On Nitrate In Area 3 Of The Enigma Field Research Site At Y-12, Erin Kelly

Masters Theses

Uranium processing and waste storage in unlined waste ponds leached contaminants into the groundwater at Y-12, Oak Ridge, Tennessee, from the 1950s to 1980s. Groundwater wells near the S-3 ponds have had the highest nitrate concentrations of groundwater anywhere in the world (>10,000 mg/L). For reference, the maximum contaminant level for nitrate in drinking water set by the U.S. Environmental Protection Agency is 10 mg/L. Since 2012, the ENIGMA (Ecosystems and Networks Integrated with Genes and Molecular Assemblies) group has been characterizing, monitoring, and conducting field experiments to understand the interactions between contaminants, microbes, and the subsurface. The goals …

Relative Soybean Response To Aminocyclopyrachlor, 2,4-D, Dicamba, And Aminopyralid, Trey I. Clark

Masters Theses

This research compared the visual symptomology of four auxin herbicides applied at three rates to simulate tank contamination on non-auxin tolerant soybeans. The herbicides examined were aminocyclopyrachlor (ACP), 2,4-D, dicamba, and aminopyralid. The standard labeled rates (SLR) used to base the application rates were 0.12 kg ae ha^-1 for ACP and aminopyralid while dicamba and 2,4-D used 1.12 kg ae ha^-1. These four herbicides exhibit similar symptoms on soybeans which is problematic when diagnosing soybean response. One goal of this project was to obtain high-quality images of the four herbicide’s effect on soybeans, with the hope of …

Growth, Browsing And Mortality In Mixed Oak And Pine Plantings, Heather Slayton

Masters Theses

The purpose of this project was to determine if different oak/pine arrangements elicited potential beneficial interactions that affected seedling growth, mortality and overall protection from deer browsing. Northern red oak (Quercus rubra L.) and shortleaf pine (Pinus echinata Mill.) were planted together and alone in six different planting patterns and spacings, replicated over three blocks in recent clearcuts in east Tennessee, USA. Each block consisted of two monocultures planted at a 3.0 by 3.0 meter (m) spacing and four multi-cropped treatments planted at varying spatial arrangements (0.3 m, 1.0 m, 1.5 m, and 3.0 m) from neighboring shortleaf …

Physicochemical Properties And Functionality Of Pardina Lentil, Navy Bean, Garbanzo Bean, And Split Pea Starches, Jenna Laughlin, Vermont Dia, Philipus Pangloli

Chancellor’s Honors Program Projects

No abstract provided.

The Effect Of Bovine Endometrial Cell Conditioned Media On In Vitro Produced Bovine Embryo Development And Gene Expression, Mary A. Oliver

Masters Theses

In vitro produced (IVP) bovine embryos provide enhanced genetic value and a means for studying early embryonic development. However, IVP embryos are developmentally compromised and are lower quality compared to in vivo derived (IVD) embryos. Consequently, after transfer pregnancy rates from IVP embryos are consistently lower, as they exhibit the highest amounts of pregnancy failure during the early embryonic phase (prior to day 28). Progesterone (P4) has been shown to influence bovine endometrial epithelial (EPI) and stromal fibroblast (SF) cells to secrete developmentally important molecules that promote early embryo development and conceptus elongation. However, IVP embryos are not exposed to …

Interseeding Native Warm-Season Grass Pastures, Jonathan D. Richwine

Doctoral Dissertations

Cool-season annual (CSA) grass and legume species, as well as warm-season forbs, can enhance established native warm-season grass (NWSG) pastures by extending the grazing season, reducing supplemental feed costs, suppressing weeds, increasing herbage production and overall forage quality, and increasing food and cover resources for pollinators and wildlife. Therefore, two NWSG experiments were conducted near Spring Hill, TN, 2018-2020, to assess three CSA seeding options (cereal rye monoculture, a cereal rye, ‘Purple Top’ turnip, ‘Trophy’ rape, ‘Frosty’ berseem clover, and ‘Dixie’ crimson clover polyculture, or non-planted control) and two warm-season N rates (0 or 67 kg N ha^-1) …

Insights Into Steinernema Carpocapsae-Xenorhabdus Nematophila Specificity And The Role Of Adult Nematode Colonization, Erin Mans

Doctoral Dissertations

The gut microbiota can provide the host with several benefits such as the production of secondary metabolites, essential amino acids, as well as the breakdown of food or protection from pathogens. The host in turn provides the microbiota with shelter and nutrients. Given the benefits that the host and microbiota receive from their association, humans and the microbiota have evolved mechanisms of selection and specificity to assure the proper symbionts colonize a host with high fidelity. Chapter two will explore mechanisms by which Xenorhabdus nematophila nematode intestinal localization (nil) genes interact with and adhere to the nematode intestinal …

Anti-Inflammatory And Chemopreventive Activity Of Lunasin From Tofu Whey For The Management Of Gastrointestinal Diseases, Cindy Andrea Nieto Veloza

Doctoral Dissertations

Gastrointestinal diseases such as inflammatory bowel diseases (IBD) and colorectal cancer (CRC) are pathological conditions associated with chronic inflammation, characterized by intestinal damage, debilitating symptoms, and detrimental health consequences. The increased risk of CRC in IBD patients, and the adverse effects associated with current therapeutic strategies, point out the need for safer alternatives to reduce chronic inflammation in the bowel. Lunasin is a bioactive peptide naturally occurring in soybeans, with chemopreventive and anti-inflammatory properties demonstrated in several extra-intestinal diseases. However, to date, there is no evidence of the biological activity of lunasin on the gastrointestinal tract as a target site. …

The Histone Variant H2av Regulates Stress Responses And Tissue Development Through Interactions With Chromatin Insulator Proteins In Drosophila Melanogaster, James Ryan Simmons

Doctoral Dissertations

The ability of a cell to sense and respond to various forms of stress is essential to maintain integrity of the genome. Numerous pathways have been implicated in cellular responses to environmental and genotoxic stresses, often involving proteins and complexes that bind DNA directly to orchestrate changes in transcription and genome organization. Chromatin insulators describe a class of protein complex that bind specific sequences in the genome and work through two classically described functions: to restrict communication between enhancers and promoters through physical separation into different genomic domains and to prevent the spread of heterochromatin into euchromatic regions of the …