Doctor of Philosophy (PhD), Ohio University, 2024, Plant Biology (Arts and Sciences)

Plants encounter various biotic and abiotic stresses daily and have developed defense mechanisms to overcome these challenges. One key system involved in these defense mechanisms is the ubiquitin (Ub)-26S proteasome system (UPS), which targets malfunctioning proteins for degradation through Ub-tagged proteasomal pathways. The E3 ligases, specifically S-phase kinase-associated protein 1 (SKP1), Cullin 1 (CUL1), and F-box (SCF) complexes, play crucial roles in this process by recognizing and tagging specific protein substrates. Arabidopsis thaliana, with over 700 F-box proteins, has the largest group of E3 ligases, yet only 5% have been functionally characterized. Phylogenetic relationships among 111 plant species have identified four clusters of F-box genes, including a cluster with more conserved F-boxes, referred to as core Arabidopsis F-box (CAF) genes. Given that CAF genes have more known functions compared to other clusters, this dissertation hypothesizes significant potential for discovering new functions among the uncharacterized F-boxes within this group. Considering the evolutionary conservation of most CAFs, I adopted a genetic approach to investigate the roles of CAFs during seed germination and seed development. To address the challenges posed by functional redundancy of duplicated CAF genes and the lethality associated with constitutive F-box overexpression in transgenic plants, I created a library of inducible overexpression lines for 40 CAF genes, many of which lacked known biological functions. By systematically examining the effects of conditional overexpression of these 40 CAFs, I found that CAF overexpression during seed germination and seed development can positively or negatively regulate radicle rupture growth, thus controlling the germination process. Specifically, I identified 24 CAFs that enhance radicle rupture and two that inhibited it by interfering with abscisic acid (ABA)-mediated germination suppression. Induction of CAFs during seed (open full item for complete abstract)

Committee: Zhihua Hua (Advisor); Yang Li (Committee Member); John Schenk (Committee Member); Morgan Vis (Committee Member) Subjects: Biology; Genetics; Molecular Biology; Plant Biology; Plant Sciences

Doctor of Philosophy, The Ohio State University, 2024, Molecular Genetics

Plant reproduction has been of interest to humans since the advent of agriculture over 10,000 years ago in ancient Mesopotamia. Knowing when and how plants reproduced allowed humans to cultivate them and gradually over time increase crop yields through unguided selective breeding. In our present day, the cycles of plant reproduction are still of paramount importance. The reproductive stage of plants is often the most susceptible to environmental fluctuations. Thus, as our climate changes, it is becoming increasingly important to understand the core molecular mechanisms of plant reproduction. For genetically engineered plants to withstand the effects of climate change, we must first understand the molecular mechanisms of plant reproduction. Unlike in animals, where each individual sperm cell is self-motile via the use of a flagella, plant sperm cells are not self-motile. They possess no flagella or means of independent motion. Instead, the sperm of plants relies on the specialized pollen tube structure to deliver plant sperm from the pollen grain to the ovule for fertilization. The pollen tube is a single cell that grows from a pollen grain in a tip-growing manner. It grows down into the female tissue of the flower. Within each pollen tube are two sperm cells. These two sperm cells connect to the vegetative nucleus of the pollen tube itself to form a unit collectively called the male germ unit. This unit traffics together through the cytoplasm of the pollen tube as it grows. The mechanism of this motion is not understood. For over 30 years, it has been proposed that this motion is achieved by motor proteins trafficking the male germ unit along the cytoskeleton of the pollen tube. However, the underlying molecular mechanisms involved in this process have remained obscure. In this work, I investigate the 61 kinesins present in the model organism Arabidopsis thaliana to identify motor proteins that play a role in the trafficking of the male germ unit and in male-der (open full item for complete abstract)

Committee: Iris Meier (Advisor); Anna Dobritsa (Committee Member); Adriana Dawes (Committee Member); Patrice Hamel (Committee Member) Subjects: Cellular Biology

Doctor of Philosophy, Miami University, 2011, Chemistry and Biochemistry

Although the glyoxalase system was discovered more than seven decades ago, its specific functional roles are still unclear. It is believed that the major role for this system is the chemical detoxification of methylglyoxal. However, the identification of isoforms that are non-catalytic with methylglyoxal and S-lactoylglutathione, a known substrate for the enzyme, has suggested that it may play additional roles. Also the observation of increased glyoxalase expression during stress conditions and diseased state, as well as the ability to introduce stress tolerance in plants by the over-expression of glyoxalase enzymes indicates that the system may be responsible for more than just methylglyoxal detoxification. The fact that the glyoxalase system is present across a range of species, and is expressed in almost all tissues highlights the significance of this system, and why it is an important topic to study. It is with this larger question that the research described herein was conducted. Specifically, the questions that this dissertation addresses are - what are the likely roles of two glyoxalase II-like enzymes (GLX2-1 and ETHE1) in Arabidopsis thaliana? To address this question we have used genetic, cellular, transcriptomic, and metabolomic tools to observe changes in the model plant Arabidopsis when expression levels of these genes are altered. The results of the study establish that GLX2-1 has a role in stress response in Arabidopsis thaliana, and that the absence of GLX2-1 increases the sensitivity of plants to stresses like anoxia (lack of oxygen) and high salt conditions. In case of ETHE1, our results suggest that perturbation of this gene causes pleiotropic effects on plant growth and survival, and possibly due to alterations in mitochondrial function.

Committee: Christopher A. Makaroff Dr. (Advisor); Michael W. Crowder Dr. (Committee Chair); Ann E. Hagerman Dr. (Committee Member); Carole Dabney Smith Dr. (Committee Member); Qingshun Quinn Li Dr. (Committee Member) Subjects: Biochemistry

Bachelor of Science (BS), Ohio University, 2024, Environmental and Plant Biology

A plant's survival is largely impacted by its ability to sense and respond to gravitational changes, such as the changes that occur in spaceflight. However, the gravitropic signaling pathway is not fully understood. In the BRIC-20 experiment aboard the International Space Station, the Arabidopsis proton pump AHA2 was found to be differentially phosphorylated in microgravity compared to ground controls. AHA2 is hypothesized to be involved between plant hormone movement and differential growth during gravity signaling. When subject to reorientation, aha2 mutant seedlings had increased root curvature compared to wild type. Furthermore, wild type seedlings treated with fusicoccin, a phytotoxin that increases AHA2 phosphorylation and activity, had increased root curvature compared to untreated plants. To determine the role of AHA2 phosphorylation in gravitropic signaling, several lines of transgenic Arabidopsis with modifications in phosphorylation sites are being developed. The transformants will then be phenotyped for altered gravity response, showing if the phosphorylation of the AHA2 protein is involved in a plant's gravity response. These findings will further knowledge on the molecular mechanisms of gravitropism to develop space-tolerant plants for life support in spaceflight and for habitation of the moon, Mars, and beyond.

Committee: Rebecca Snell (Advisor); Sarah Wyatt (Advisor) Subjects: Plant Biology

Doctor of Philosophy, The Ohio State University, 2023, Plant Pathology

Plants exist in a constantly evolving microbial environment that significantly influences their growth, development, and overall well-being. Within this microbial milieu, certain bacteria play a pivotal role in enhancing plant health and growth. These beneficial bacteria are collectively referred to as plant growth-promoting bacteria (PGPB). They offer valuable services to plants, including improved nutrient absorption, heightened growth stimulation, and increased resilience against pathogens and the other environmental adversities. PGPB engage with plants through diverse modes of interaction, such as root colonization, endophytic association, or rhizosphere competence. An in-depth comprehension of the molecular mechanisms and ecological dynamics governing these interactions is essential for unlocking the potential of PGPB in promoting sustainable agriculture and environmental remediation. In Chapter 1, I provide an overview of current methods used to detect and diagnose Pseudomonas syringae. This encompasses traditional approaches like culture isolation and microscopy, as well as modern techniques such as PCR and ELISA. Furthermore, I explore the upcoming advancements in this domain, emphasizing the necessity for highly sensitive and specific methods to detect pathogens even at low concentrations. Additionally, I delve into approaches for diagnosing P. syringae infections when they coexist with other pathogens. Chapter 1 Figures can be found in Appendix A. In Chapter 2, I present a significant protocol for monitoring the progression of gray mold fungal infection at various developmental stages of strawberries. I detail three distinct in vivo inoculation methods for Botrytis cinerea on strawberry plants, focusing on early, middle, and late stages of strawberry growth. Chapter 2 Figures can be found in Appendix B. In Chapter 3, I introduce Bacillus proteolyticus OSUB18 as a novel inducer of ISR (Induced Systemic Resistance). This bacterium enhances plants' r (open full item for complete abstract)

Committee: Ye Xia (Advisor); Christopher Taylor (Committee Member); Yu (Gary) Gao (Committee Member); Lisa (Beck) Burris (Committee Member); Jonathan Jacobs (Committee Member) Subjects: Agriculture; Agronomy; Biochemistry; Bioinformatics; Biology; Botany; Cellular Biology; Plant Biology; Plant Pathology; Plant Sciences

Master of Science (MS), Bowling Green State University, 2020, Biological Sciences

Understanding plant-plant communication further elucidates how plants interact with their en-vironment, and how this communication can be manipulated for agricultural and ecological purposes. Part of understanding plant-plant communication is discovering the mechanisms be-hind plant-plant recognition, and whether plants can distinguish between genetically like and unlike neighbors. It has been previously shown that plants can “communicate” with neighbor-ing plants through airborne volatile organic compounds (VOCs), which can act as signals relat-ed to different environmental stressors. This study focused on the interaction among different genotypes of the annual plant Ar-abidopsis thaliana. Specifically, a growth chamber experiment was performed to compare how different genotypes of neighboring plants impacted a focal plant's fitness-related phenotypes and developmental stages. The focal plant genotype was wild type Col-0, and the neighboring genotypes included the wild type Landsberg (Ler-0), and the genetically modified (GM) geno-types: Etr1-1 and Jar1-1. These GM lines have a single point-mutation that impacts their abil-ity to produce a particular VOC. This allows for the evaluation of a particular role that a VOC may have on plant-plant airborne communication. Plants were grown in separate pots to elimi-nate potential belowground interactions through the roots, and distantly positioned to avoid aboveground physical contact between plants. In addition, to avoid potential VOC cross-contamination between different treatments (genotypes), each neighboring plant treatment oc-curred in separate, sealed growth chambers. Results showed that when A. thaliana Col-0 plants were grown alongside neighbors of different genotypes, they exhibited some significant differences in fitness-related traits, such as increased rosette width, stem height, aboveground biomass, and total fruit number. However, these results differed with neighbor identity, and when the experiment was (open full item for complete abstract)

Committee: Maria Bidart Dr. (Advisor); Heidi Appel Dr. (Committee Member); Vipa Phuntumart Dr. (Committee Member) Subjects: Biology

Doctor of Philosophy (PhD), Ohio University, 2020, Molecular and Cellular Biology (Arts and Sciences)

Plants use a myriad of environmental cues to inform their growth and development. The force of gravity has been a consistent abiotic input throughout plant evolution, and plants utilize gravity sensing mechanisms to maintain proper orientation and architecture. Despite thorough study, the specific mechanics behind plant gravity perception remain largely undefined or unproven. At the center of plant gravitropism are dense, specialized organelles called starch statoliths that sediment in the direction of gravity. Herein I describe a series of experiments in Arabidopsis that leveraged RNA sequencing to probe gravity response mechanisms in plants, utilizing reorientation in Earth's 1g, fractional gravity environments aboard the International Space Station, and simulated fractional and hyper gravity environments within various specialized hardware. Seedlings were examined at organ-level resolution, and the statolith-deficient pgm-1 mutant was subjected to all treatments alongside wildtype seedlings in an effort to resolve the impact of starch statoliths on gravity response. In all, 132 unique genotype/tissue/treatment datasets were collected to help further our understanding of the gravitropic mechanisms in plants.

Committee: Sarah Wyatt Ph.D. (Advisor); Michael Held Ph.D. (Committee Member); Morgan Vis Ph.D. (Committee Member); Ronan Carroll Ph.D. (Committee Member) Subjects: Biology; Plant Biology; Plant Sciences

Master of Science (MS), Bowling Green State University, 2019, Biological Sciences

Changes in the level of polyamines enable plants to respond optimally to both biotic and abiotic stresses such as increased salinity, drought, chilling, flooding, heavy metals and increased concentrations of reactive oxygen species. To identify new classes of transporters that mediate movement of polyamine between cells and within organelles, this study focused on the OCT family in the model plant Arabidopsis thaliana. The A. thaliana OCT family contains six members with no splice forms and have been less studied. Because the expression of OCT5 is upregulated during salt stress assays of seedlings, we tested the response of oct5 seedlings under these conditions. In the salt assays, oct5Δ mutants showed faster bleaching of leaves than the wild type, a common phenotype associated with increased sensitivity to salt stress. To determine whether OCT5, could function as a polyamine transporter, OCT5 was heterologously expressed in WT yeast and in tpo5Δ, a yeast strain deficient in polyamine export. The dilution of rapidly growing yeast cells in liquid culture to fresh media containing elevated levels of putrescine, resulted in an inhibition of growth for all strains in response to 150 or 200 mM putrescine. WT cells expressing OCT5 were more sensitive to exogenous putrescine than WT cells alone. As expected, the tpo5Δ yeast strain was more sensitive to exogenous putrescine than WT cells, but the heterologous expression of OCT5 in this strain did not result in further growth inhibition. The inhibition of growth in WT cells expressing OCT5 was unexpected, since this gene is localized to the vacuole in plants and increased expression of this gene was expected to have a protective effect on cell growth by having this transporter sequester putrescine from the cytoplasm in the vacuole. However, in humans, OCT transporters are polyspecific and are believed to mediate substrate transport in either direction. Thus the increased sensitivity to putrescine when this gene was ex (open full item for complete abstract)

Committee: Paul Morris Dr. (Advisor); Vipaporn Phuntumart Dr. (Committee Member); Helen Michaels Dr. (Committee Member) Subjects: Biology

Doctor of Philosophy, The Ohio State University, 2019, Evolution, Ecology and Organismal Biology

Herbicide resistant weeds are among the greatest threats facing modern agriculture. Glyphosate, the active ingredient in the commercial herbicide RoundUp, is the most widely applied herbicide worldwide, and 43 weed species have evolved resistance to glyphosate to date. My research addressed four key questions about the strength, mechanisms, and fitness effects of glyphosate resistance using Conyza canadensis, a representative glyphosate-resistant weed, and Arabidopsis thaliana, a model plant species. In northcentral Ohio and southern Iowa, maternal biotypes (individual plants) of Conyza canadensis, also known as horseweed or marestail, were collected from 74 locations (both agricultural and non-agricultural) in both states. Dose-response experiments were used to categorize biotypes into resistance categories based on 80% survival at 0x only (Susceptible, S), and up to 1x (equivalent to 840 g ae ha-1; R1), 8x (R2), 20x (R3), and 40x (R4). Extreme glyphosate resistance (R4 biotypes) was quite common in both states and both habitats, and non-agricultural habitats served as a refuge for R4 biotypes. Glyphosate resistance mechanisms are generally presumed to impose a fitness cost due to possible trade-offs in resource allocation to plant defense, growth, and reproduction. Nine S, eight R1, and nine R4 biotypes originally collected in Iowa were grown in a common garden experiment in Iowa over two years and two sites to test for fitness effects. Based on early rosette sizes and days to bolting, nested ANOVAs showed that R4 biotypes grew as large as, if not larger than, both S and R1 biotypes, and bolted significantly earlier. Furthermore, R1 and R4 biotypes were less likely to display disease symptoms than S biotypes. Glyphosate resistance in horseweed appears not to impose an early growth penalty, and possibly no lifetime fitness cost. Specific mechanisms of glyphosate resistance in horseweed include altered translocation and vacuolar sequestration. Recently, a Canadi (open full item for complete abstract)

Committee: Allison Snow (Advisor); Stephen Hovick (Committee Member); Kristin Mercer (Committee Member) Subjects: Agriculture; Agronomy; Biology; Ecology; Evolution and Development

Doctor of Philosophy, The Ohio State University, 2017, Molecular Genetics

Transposable elements (TEs) are mutagenic DNA fragments that make multiple copies of themselves, much like viruses. TEs occupy large regions of eukaryotic genomes; almost 50% in humans. If unregulated, active TEs cause large-scale chromosomal damage, instability and mutations. The mutagenic activity of TEs is also closely linked to the progression of cancer. To protect themselves against mutations, cells evolved robust and interconnected mechanisms to keep TEs inactive and silent. After years of research, pioneered in the model organism Arabidopsis thaliana, we now understand how a TE is maintained in a silenced state. However, how a TE is originally recognized as a harmful sequence to be silenced is one of the major remaining questions of the field. Small RNA-directed DNA methylation (RdDM) is a key TE silencing pathway well studied in the reference plant Arabidopsis. Canonically, RdDM was though to function through 24 nucleotide (nt) small RNAs (sRNAs). During my initial years of Ph.D., I analyzed small RNA sequencing in key mutant lines to provide genetic evidence that 21-22 nt sRNAs are also responsible for RdDM. I proposed that this novel 21-22 nt sRNA dependent RdDM (termed RDR6-RdDM) might be the missing link to explain the origin of TE silencing. For a deeper mechanistic understanding of this pathway I developed custom bioinformatics approaches and showed that 21-22 nt sRNAs are getting incorporated into a key protein AGO6 to drive RdDM. I performed whole genome methylation analysis on mutant plants of canonical and 21-22 nt sRNA-dependent RdDM factors to understand if the two RdDM pathways act on disjoint sets of TE targets. I characterized the genome-wide targets of both the RdDM processes and identified that full-length TEs capable of self-transposing are the major targets of the RDR6-RdDM pathway. This demonstrates that RDR6-RdDM is likely the more critical pathway to repress TE mobility and formation of new TE-induced mutations. Most studies inves (open full item for complete abstract)

Committee: R. Keith Slotkin (Advisor); Robin Wharton (Committee Member); Jay Hollick (Committee Member); Adriana Dawes (Committee Member) Subjects: Bioinformatics; Biology; Genetics; Molecular Biology

Master of Science, Miami University, 2017, Cell, Molecular and Structural Biology (CMSB)

The unique Twin Arginine Translocation (Tat) pathway which is composed of TatA, TatB and TatC, transports fully folded proteins without the use of ATP energy. It was thought to be lost from the mitochondrion, the powerhouse of the cell during post-endosymbiotic evolution. This study investigates the stress induced expression of a minimal, mitochondrial Tat pathway in Arabidopsis thaliana. We treated plants with salicylic acid (SA) stress which mimics the hypersensitive response and studied the putative mitoTat components over a 24-hour time period. qRT-PCR analysis indicated the upregulation of the mitochondrial gene mtTATC. Furthermore, immunoblot detection confirmed that the mtTATC protein is expressed at high SA concentrations. However, a minimal Tat system capable of translocation requires TatC as well as TatA (Tha4). Confocal microscopy data established the dual localization of nuclear encoded, chloroplast Tha4-GFP to the mitochondria. Together, our data illustrate the existence of a putative minimal mitoTat pathway at 4 hours post-treatment with high SA concentrations. Finally, we discuss the physiological significance of a SA-induced minimal mitoTat pathway in plant pathology.

Committee: Carole Dabney-Smith Dr (Advisor); Heeyoung Tai Dr (Committee Chair); Richard Moore Dr (Committee Member); David Pennock Dr (Committee Member) Subjects: Biochemistry; Cellular Biology; Molecular Biology; Plant Biology; Plant Pathology

Master of Science, Miami University, 2017, Chemistry and Biochemistry

Cohesins play a significant role in chromosome segregation during mitosis and meiosis. However, cohesion-involved proteins have never been characterized in organelles like chloroplasts. In this study, we investigated the subcellular localization and function of an Arabidopsis (Arabidopsis thaliana) SYN3 protein. SYN3 is an Arabidopsis a-kleisin that is essential for megagametogenesis and is enriched in the nucleolus of mitotic and meiotic cells. Previous work has established the role of a-kleisins, including SYN3, in the nucleus; however, a-kleisins have not been shown to be localized to the organelles. SYN3 protein was found to interact with the FtsZ through yeast two-hybrid screening. FtsZ is essential for chloroplast division. To that end, we generated transgenic Arabidopsis plants that over-expressed SYN3 proteins fused to yellow fluorescent protein (YFP). SYN3 was found to be localized to the thylakoids in chloroplasts isolated from Arabidopsis. Over-expression of SYN3-YFP resulted in stunted growth, abnormal phenotype with significantly reduced chlorophyll b and total chlorophyll content of plants. Further, our results show that over-expression of SYN3-YFP may have effects on chloroplast division.

Committee: Michael W Crowder (Committee Member); Richard C Page (Committee Chair); Makaroff Christopher. A (Advisor); Carole Dabney-Smith (Advisor) Subjects: Biochemistry

Doctor of Philosophy (PhD), Ohio University, 2017, Plant Biology (Arts and Sciences)

Throughout this dissertation I approach the long-term aim of improving photosynthesis through the lens of natural genetic variation for photosynthesis. To date few studies have directly asked how photosynthetic variation might inform or provide the genetic material required to enhance photosynthesis, despite the clear utility of this strategy for other types of agronomic improvement. Of the many traits underling variation in photosynthesis, mesophyll conductance – the diffusional flux of CO2 through the leaf interior – has potential to improve both photosynthesis and water use efficiency. I assess genetic variation for photosynthesis among ecotypes of the model plant Arabidopsis thaliana and cultivars of soybean (Glycine max). In both species, and across both controlled and field environments in soybean, I find heritable genetic variation for mesophyll conductance that is positively correlated to variation in photosynthetic rate, indicating that selection to enhance mesophyll conductance will increase photosynthesis. Genetic variation in mesophyll conductance though was largely unrelated to variance in water use efficiency as a result of phenotypic correlation between stomatal and mesophyll conductance. If trait variation is to prove useful for crop breeding, that trait must not have already been improved in the varieties currently used by farmers. In soybean, photosynthesis has improved slightly with breeding for yield across a historical set of cultivars. Mesophyll conductance is not responsible for this increase in photosynthesis; it remains unchanged after 75 years of selection for yield. Stomatal conductance is greater in modern varieties and I show that this increase scales from the leaf to the canopy. Greater canopy conductance in modern soybeans resulted in lower canopy temperatures and reduced leaf heat-stress. Few leaf-level photosynthetic traits were improved across this historical set of soybean cultivars. Given that I observed heritable genetic variatio (open full item for complete abstract)

Committee: David Rosenthal (Advisor); Ahmed Faik (Committee Member); Jared DeForest (Committee Member); Ryan Fogt (Committee Member) Subjects: Agronomy; Ecology; Physiology; Plant Biology

Doctor of Philosophy, The Ohio State University, 1985, Graduate School

Committee: Not Provided (Other) Subjects: Biology

Doctor of Philosophy, The Ohio State University, 1983, Graduate School

Committee: Not Provided (Other) Subjects: Biology

Doctor of Philosophy, The Ohio State University, 1981, Graduate School

Committee: Not Provided (Other) Subjects: Biology

Doctor of Philosophy, The Ohio State University, 1976, Graduate School

Committee: Not Provided (Other) Subjects: Biology

Doctor of Philosophy, The Ohio State University, 1974, Graduate School

Committee: Not Provided (Other) Subjects: Biology

Doctor of Philosophy, Case Western Reserve University, 2015, Biology

The Linum Insertion Sequence (LIS-1) is a unique element appearing as a site-specific insertion event in flax responsive lines responding to certain growth conditions and can be transmitted to subsequent generations. LIS-1's origin is uncertain, but one theory is that LIS-1 is assembled from small sequences found scattered throughout the genome, and inducing (stress) conditions can result in these sequences rearranging and joining together to build the full LIS-1 sequence, which is inserted into the “target site.” This study's primary question was to determine whether LIS-1 was a unique event to the flax family or would it have similar behavior in other plant species. Therefore, this work focused to develop transgenic plants containing LIS-1 in their genome and to follow LIS-1 stability and inheritance in subsequent generations. The first part of the project focuses on Arabidopsis thaliana. The rationale was to determine whether LIS-1 is mobilized in other plants through the T1 and T2 generations. Different accessions of Arabidopsis thaliana were transformed with either LIS-1 or with its target site, using the well-established floral dipping method via Agrobacterium. In the second part of the project, the main question was how flax varieties deal with an intact “exogenous” LIS-1. A novel technique of transforming flax using Agrobacterium via floral dipping was developed to transform an “exogenous” LIS-1 to flax varieties. The fate was followed in the T1 and T2 generations under different growth conditions. Both projects show that “exogenous” LIS-1 is not found intact in any transformed plants. However, the results of LIS-1 transformation into flax were consistent with LIS-1 transformation into the Arabidopsis thaliana. In both plants, the regions flanking LIS-1 in the T-DNA construct were converted back to the flax's progenitor target site in all T1 generations, followed by either complete excision or stability of this form in the T2 generations. The results (open full item for complete abstract)

Committee: Christopher Cullis (Advisor); Stephen Haynesworth (Committee Member); Emmitt Jolly (Committee Member); Ahmad Khalil (Committee Member); David Burke (Committee Member); Ryan Martin (Committee Chair) Subjects: Biology; Genetics; Molecular Biology

Master of Science, Miami University, 2014, Chemistry and Biochemistry

Mutations in the human ethylmalonic encephalophathy (ETHE1) protein result a chronic metabolic disease and infants born with this disease will live only the first decade of their lives. Common symptoms of this disease are chronic diarrhea, a delay in neural development, and lactic acidemia. ETHE 1 is found in a wide range of organisms including bacteria, plants and animals. Mutations in plant ETHE1 results in alterations in endosperm development and a delay in embryo development, but the biochemical role of ETHE1 in plants is unclear. In this study we analyzed the metabolite levels in two Arabidopsis suspension cell lines containing different ETHE1 proteins. Metabolites were screened using NMR and principal component analysis was performed to identify metabolites that exhibited significant concentration differences. In this study we found that all the cells were undergoing stress and metabolites associated with a response to stress were elevated. It was also observed that the ETHE1 overexpression cell lines exhibited stress tolerance.

Committee: Christopher Makaroff PhD (Advisor); Ann Hagerman PhD (Committee Chair); Michael Kennedy PhD (Committee Member); Carole Dabney-Smith PhD (Committee Member) Subjects: Biochemistry; Chemistry