Life Sciences Commons^™

Comparative Functional Genomics Of The Sabath Family Of Methyltransferases In Plants, Nan Zhao

Doctoral Dissertations

Known members of the plant SABATH family of methyltransferases (MTs) have important biological functions by methylating hormones, signaling molecules and other metabolites. This dissertation aims to systematically investigate the biochemical and biological functions and evolution of SABATH genes in plants. The genomes of rice and poplar have been fully sequenced, which provides unprecedented opportunities for cross-species comparison of the SABATH family. Using a comparative genomic approach, 41 and 33 SABATH genes were identified in rice and poplar, respectively. The expression of these genes in different tissue was analyzed using RT-PCR approach and some genes highly expressed in multiple tissues were …

Plant Improvement For Insect Resistance: Testing Of The Candidate Organism Beauveria Bassiana, Transgenic Tobacco Expressing Protease Inhibitors, And Rapid Screen Of Insect Resistance Genes In An Agroinfiltration Transient Expression System, Brian M. Leckie

Doctoral Dissertations

This study focused on three aspects of plant improvement for insect resistance including: testing of candidate organisms for their production of insecticidal proteins, testing of transgenic plants expressing insect resistance genes, and testing novel systems for the evaluation of insect resistance genes. In the initial part of this study, the candidate fungus Beauveria bassiana was tested for its production of insecticidal proteins through a series of insect bioassays containing fungal protein extracts. These extracts were shown to be orally toxic to Plutella xylostella (diamondback moth) and Spodoptera frugiperda (fall armyworm). Assays involving protease treatments significantly decreased mortality indicating the presence …

Plant Transcriptional Responses To Explosives As Revealed By Arabidopsis Thaliana Microarrays And Its Application In Phytoremediation And Phytosensing, Murali Malavalli Keerthi Narayana Raghavendra Rao

Doctoral Dissertations

This research focused on understanding genetic responses of plants to explosives, which is necessary to produce plants to detect and clean soil and water contaminated with toxic explosive compounds. The first study used microarray technology to reveal transcriptional changes in the model plant Arabidopsis thaliana exposed to the explosive compounds RDX (hexahydro-1,3,5-trinitro-1,3,5-triazine; Royal Demolition Explosive or Research Department Explosive) and TNT (2,4,6-trinitrotoluene). This study yielded a list of genes up- and downregulated by explosive compounds, which can be potentially used for phytoremediation (remediation using plants) or phytosensing (detection using plants) of explosive compounds. The second study presented biotechnology tools to …

Biology And Ecology Of Palmer Amaranth (Amaranthus Palmeri), Prashant Jha

All Dissertations

Palmer amaranth (Amaranthus palmeri S. Wats.) is a troublesome weed of crops in southeastern United States. This research highlights studies on the biology and ecology of Palmer amaranth. Following dispersal in fall, Palmer amaranth seeds require high mean temperatures of 25 to 40 C for germination, which is not likely to occur in South Carolina until the following spring. With dormancy reduction over winter, seeds can germinate at high temperatures (≥25 C) and thermal amplitudes of 15 C during late spring (May) in the presence of light. A majority (>90%) of the non-dormant population in the soil seedbank emerge …

Dwarfing Mechanisms Of Prunus Species As Interstems And Rootstocks On Peach [Prunus Persica (L.) Batsch] Tree Vegetative Growth And Physiology, Antonio Weibel

All Dissertations

The use of small trees in orchard systems reduces manual labor (pruning, thinning and harvesting), and induces precocity, thus making high-density plantations economically advantageous, which has elicited an interest in size-controlling rootstocks. However, the mechanisms involved in the reduction of scion growth by the rootstock are not well understood. The main objective of this study was to gain a better understanding of the dwarfing mechanism induced by size-controlling peach rootstocks. The relationship among different rootstocks (dwarfing to invigorating range) as to stored carbohydrates, tree water status, and interstem and grafting height was evaluated on young and mature `Redhaven' and `Redtop' …

Characterization Of The Metallohistin Cdna Agnt84 And Pteris Vittata Tissue Culture For Phytoremediation, Blake Lee Joyce

Masters Theses

Contamination of soils with toxic metals such as arsenic and cadmium has become a major environmental and human health risk. Phytoremediation provides a method to remove contaminants from soils that is not only economically viable but also environmentally sound. Metallohistins are proteins that have the capability to bind divalent metal ions such as Ni²⁺, Zn²⁺, Co²⁺, Cu²⁺ and Cd²⁺. In this study, a concatemer sequence was designed to try to increase the presence of metal-binding proteins in transgenic plants. Two methods to increase translational efficiency of the metallohistin protein were used: …

Tissue Culture And Recombinant Dna Technology: Developing Protocols For Potentially Higher Yielding Switchgrass Cultivars, Stephen Michael Foulk

Masters Theses

The purpose of this thesis project was to, firstly, establish and optimize protocols for high-throughput callus induction and plant regeneration for the new, higher yielding switchgrass (Panicum virgatum L.) cultivars NSL and SL93. Secondly, to subclone the complementary DNA (cDNA) of the anthocyanin transcription factor, C1, from pBECKS.red into pUC18 and pBSL15 for downstream use.

For the first part of this project the cultivars, NF/GA992, NF/GA993, NSL, and SL93, were tested for callus induction by plating whole dehusked caryopses on callus induction media (CIM) containing 8.5uM of the auxin dicamba. NF/GA992 responded best to the treatment with 44% of …

Combining Environmental History And Soil Phytolith Analysis At The City Of Rocks National Reserve: Developing New Methods In Historical Ecology, Lesley Morris

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Historical ecology is an emerging and interdisciplinary field that seeks to explain the changes in ecosystems over time through a synthesis of information derived from human records and biological data. The methods in historical ecology cover a wide range of temporal and spatial scales. However, methods for the more recent past (about 200 years) are largely limited to the human archive and dendrochronological evidence which can be subject to human bias, limited in spatial extent or not appropriate for non-forested systems. There is a need to explore new methods by which biological data can be used to understand historic vegetation …

Ecotypic Variation In Elymus Elymoides Subspecies Brevifolius Race C In The Northern Intermountain West, Matthew C. Parsons

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Little information is available on the extent of local adaptation for many native grass species. This is the case for squirreltail (Elymus section Sitanion), despite this group's prevalence and importance in rangeland restoration efforts. I evaluated 32 populations of E. elymoides ssp. brevifolius race C, a phylogenetic subdivision of bottlebrush squirreltail (E. elymoides) centered in the northern Intermountain West, for phenotypic variables and neutral genetic markers to measure their association with geographical origin. Phenotypic traits were measured in common field and greenhouse environments, and genetic diversity was assessed using Amplified Fragment Length Polymorphism. Three factors were extracted from the phenotypic …

Buyer And Grower Perceptions Of Liner Quality And Associated Production Costs Of Nursery Liner Stock, Andrew H. Jeffers

Masters Theses

Liner production is a key segment in the nursery industry. Due to a lack of specific of quality standards by governing industry organizations as well as a lack of general consensus among growers of perceived liner quality, a conjoint analysis study was developed to determine buyer and grower preferences for nursery liner product features during point-of-purchase decisions. The study used a visual survey using six variables (first order lateral roots (FOLR), price, region of production, and height, canopy density and caliper uniformity) with varying levels yielding a 3 x 3 x 3 x 2 x 2 x 2 factorial design. …

Aminoglycosides And Syringomycin E As Fungicides Against Fusarium Graminearum In Head Blight Disease, Yukie Kawasaki

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Fusarium graminearum is one of the most problematic phytopathogens in US agriculture. This fungus causes head blight, foot rot, and damping off on wheat and barley. The infection lowers the grain yield and causes contamination of the grain product with mycotoxins. Effective control measures are lacking, and new fungicides that kill F. graminearum but remain safe and economical to use are needed. Newly synthesized aminoglycosides (JL22, JL38, JL39, JL40, NEOF004, NEOF005), classic aminoglycosides (amikacin, gentamicin, kanamycin A, kanamycin B, neomycin, and ribostamycin), and a lipopeptide, syringomycin E (SRE), were studied to determine their antifungal potential to control F. graminearum. …

Soil Moisture Responses In Traditional And Drought Adapted Landscapes In The Intermountain West, James Gregory

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Water conservation in the Intermountain West will be an important issue in the future as population and demand for limited water resources increases. In Utah, outdoor water use accounts for up to 60% of total per capita water use with 67% of that outdoor water being used to irrigate non native plant species to maintain a uniform green appearance. The objective of this study was to measure intra landscape changes in soil water potential during a 21.5 day dry down from DOY 215 to 236.5 in the summer of 2005 and 2006. Four, 2 x 2 replicated traditional and drought …

Ethylene Synthesis And Sensitivity In Crop Plants, Joseph F. Romagnano

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The gaseous plant hormone ethylene is a small molecule that regulates developmental change. Research was conducted in three areas: sensitivity, synthesis, and alterations to synthesis. Vegetative pea plants were more sensitive than radish plants to atmospheric ethylene. Light intensity did not affect ethylene sensitivity. Ethylene synthesis rates were measured for unstressed cotton, corn, soybean, and tomato plants. The per-plant ethylene synthesis rate ranged from 0.1-80 pmol plant^-1 s^-1. However, when normalized to net photosynthetic rate, this range was 1-4 µmol of ethylene synthesis per mol of CO₂ uptake. Diurnal cycles in ethylene synthesis were present in …

Growing Wild: Crested Wheatgrass And The Landscape Of Belonging, Lafe Gerald Conner

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Crested wheatgrass arrived in North America at the turn of the twentieth century through the foreign plant exploration missions sponsored by the United States Department of Agriculture. During the first two decades of the new century, scientists tested the grass at agricultural experiment stations. They determined it was useful for grazing and particularly valuable because it could grow in drought conditions with little or no care and would continue to produce high quality feed even after several years of heavy use. Beginning in the 1930s federally sponsored land utilization and agricultural adjustment programs sponsored the use of crested wheatgrass for …

Evaluation Of Competition Between Turfgrass And Trees In The Landscape, Christopher A. Hendrickson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Population growth in regions of the Intermountain West has resulted in rapid growth of residential neighborhoods. In Utah, the landscapes associated with these expanding neighborhoods consume vast quantities of treated water. This is a concern in all states of the Intermountain West, as water becomes increasingly scarce. Traditionally used turfgrasses, trees and other plants in Intermountain West landscapes require significant amounts of supplemental water considering the intense sunlight, dry winds and sparse rainfall typical of the region. Characterizing the interactions between turfgrass and tree species in these landscapes can aid in the identification of candidate species that consume less nutritional …

Impacts Of Root Invigoration And Its Individual Components On The Performance Of Red Maple (Acer Rubrum), Kelby Fite

All Dissertations

The Root Invigoration process involves soil decompaction with an air tool, amendment with organic matter and prescription fertilizer, and mulching. In the current study, we measured soil chemical and physical properties, tree characteristics, and root system responses to this process and its individual components. Treatments included Root Invigoration (AFM), mulch only (M), fertilization only (F), Airspade® tillage only (A), and an untreated control (C). The experiment was conducted from 2005-2007 at four urban sites: Anderson, SC; Boston, MA; Myrtle Beach, SC and Pittsburgh, PA. Soil strength was initially reduced by Airspade®, mulch and AFM; however only AFM-treated soils sustained this …

Characterization Of The Pathway Leading To The Synthesis Of Salicylic Acid In Plants Resisting Pathogen Infection., Alexander Eddo

Electronic Theses and Dissertations

Salicylic acid is a plant hormone that accumulates with plant-pathogen interaction. This accumulation corresponds to the plant being resistant to infection and without it the plant is susceptible. In this study, primers of genes involved in the normal synthesis of SA were used in RT-PCR to compare gene expression levels in susceptible and resistant plants challenged with tobacco mosaic virus. Because SA synthesis shares chorismate as a common substrate with the synthesis of aromatic amino acids, HPLC was used to determine whether the increase in SA could be attributed to a decrease in amino acid levels. The results suggest that …

Synthesis Of Novel Agrochemicals As Potential Plant Immunization Agents., Arrey Besong Enyong

Electronic Theses and Dissertations

The world's population is expected to grow from 6 billion to about 10 billion by 2050. The greatest population increase is expected to occur in Africa, Latin America, and Asia. To feed a world with huge increases in population and to sustain the well-being of humans, a large increase in food production must be achieved. The projected increase in food production must be accomplished on the existing cultivated areas because the expansion of new land is limited by environmental concerns, urbanization and increasing water scarcity.

Different compounds have been developed for the "immunization" of plants against several pathogens. These compounds …

Interactions Between Alfalfa Mosaic Virus And Soybean Mosaic Virus In Soybean, Martha Maria Malapi-Nelson

Masters Theses

Viral synergism occurs when two or more unrelated viruses simultaneously infect the same plant and the multiplication of one of the viruses is enhanced. This is generally associated with no change(s) in multiplication of the other viruses involved. Synergism also results in intensification of symptoms. In mixed-infection, viruses may also interact in an antagonistic manner, where one virus suppresses the replication or accumulation of another virus. This phenomenon is uncommon, and only two cases have been reported where the coat protein (CP) accumulation of one of the viruses has decreased. A number of synergistic interactions studied involve viruses belonging to …

Effect Of Pod Maturity And Plant Spacing On Isoflavone Content And Harvest Force Of Edible Soybeans [Glycine Max (L.) Merrill], Allison E. Stewart

Masters Theses

In recent years consumer interest in edamame increased in part due to reported health benefits associated with vegetable soybeans. Consequently, interest in soybean production has increased steadily. This research consists of three related studies. A spacing and planting date study was performed to compare four soybean lines. This experiment utilized four plant spacings and three planting dates. The lines were grown at the Plateau Research and Education Center in Crossville, TN in 2005 and 2006. Seeds were harvested at the R6 and R8 reproductive stages. Samples were analyzed by HPLC for isoflavone content. Data from the R6 harvest confirmed previously …

Identification And Management Of Moss And Phytopathogenic Algae Common On Creeping Bentgrass Putting Greens, Steven Michael Borst

Masters Theses

Taxonomic traits were utilized to identify problematic moss species common to golf course putting greens. Three predominant species of moss were identified on two golf course putting greens located in East Tennessee. Bryum argenteum, Amblystegium serpens and Entodon seductrix were identified on creeping bentgrass putting greens. Green house studies were initiated to investigate all three moss species control with carfentrazone and mancozeb. Utilizing digital image analysis investigations concluded carfentrazone controlled all three moss species greater than mancozeb. Sequential carfentrazone applications controlled all three moss species greater than single applications. Moss recovery and regrowth was observed with carfentrazone.

Field studies …

Detection And Validation Of Agronomic And Seed Quality Quantitative Trait Loci In Soybean, Catherine Nyaguthii Nyinyi

Masters Theses

Soybean seed quality and agronomic traits are important commercially. Agronomic traits such as yield, plant height, lodging, and adapted maturity have been the primary focus of breeders for many years. Seed quality traits are also important as they affect the market price of soybean. Higher protein soybean historically is valued more per unit. It is the goal of plant breeders therefore to simultaneously improve seed quality and agronomic traits. Seed quality and agronomic traits are quantitative traits whose inheritance is governed by many genes, and whose expression is subject to environmental variation. Furthermore, negative correlations between yield and protein, and …

The Effect Of Ginseng On Biofilm Formation By Wild Type And Mutant Strains Of Pseudomonas Aeruginosa, Premi Shekar

Morehead State Theses and Dissertations

A thesis presented to the faculty of the College of Science and Technology at Morehead State University in partial fulfillment of the requirements for the Degree of Master of Science by Premi Shekar on June 25, 2008.

Foundations And Interpretations Of Quantum Mechanics, Cory Johnson

Honors Theses

The first famous thought experiment of Einstein gives rise to his theories of relativity, the bedrock of modern astrophysics and cosmology. His second famous thought experiment begins the investigation into the foundations of quantum mechanics. It leads to a paradox, inspiring various 'no-go' theorems proven by Bell, Kochen, and Specker. Physicists and philosophers worldwide become increasingly dissatisfied with the probabilistic complementarity interpretation (Born-Bohr) and eventually offer their own accounts of the theory. By the end of the 20th century two alternative approaches stand out as the best candidates: Both the hidden variables interpretation (de Broglie-Bohm) and the many worlds interpretation …

Effects Of Context Of Natural And Artifactual Objects On Categorization, Linsey Walker

Honors Theses

Categorization of animals and vehicles in different contexts was investigated in three experiments using event related potentials (ERPs). The presence of a background and congruency of the background in relation to the object were both manipulated in order to determine the effects of context on visual processing. In Experiment 1, adults were presented with images of animals and vehicles in two conditions: situated in a congruent context (e.g. an animal in a field) and in the absence of a context (an animal in a white homogeneous background). In experiment 2, adults were presented with images of animals and vehicles in …

Application And Optimization Of Bioluminescence Resonance Energy Transfer (Bret) For Real Time Detection Of Protein-Protein Interactions In Transgenic Arabidopsis As Well As Structure-Based Functional Studies On The Active Site Of Coelenterazine-Dependent Luciferase From Renilla And Its Improvement By Protein Engineering, Jongchan Woo

Doctoral Dissertations

Bioluminescence resonance energy transfer (BRET) is a biological phenomenon in some marine organisms such as Renilla reniformis and Aequorea victoria. In BRET, resonance energy from decarboxylation of coelenterazine, a substrate of Renilla luciferase (RLUC), is transferred to its acceptor such as green fluorescent protein (GFP) or yellow fluorescent protein (YFP), dependent on a distance of around 5 nm between the energy donor (RLUC) and its acceptor. The activation of the energy acceptor results in a spectral change in luminescence emission. The BRET system allows investigation of in vivo protein-protein interactions in real time. This was demonstrated with two heterodimeric …

Facilitating Private Forestland Management: Relating Landowners’ Experience Of Their Forestland And Their Conceptualization Of Forest Management To Their Management Behavior, Miriam L.E. Steiner Davis

Doctoral Dissertations

Privately owned forestland accounts for the majority of forested land in the US and provides numerous ecological, economic and social benefits to its owners and society at large. However, numerous issues ranging from fragmentation and parcelization, to pressure from the forest products industry, to increasing land values for development and real estate interests threaten to “unravel” the forest landscape. Active management of forestland is seen as one way to combat such threats. Active management of private forestland has been linked to numerous factors such as private forest landowners’ (PFLs’) general education level and familiarity with forest management, their goals, interests, …

Non-Target Effect Of Imidacloprid On The Predatory Arthropod Guild On Eastern Hemlock, Tsuga Canadensis (L.) Carriere, In The Southern Appalachians, Abdul Hakeem

Masters Theses

Imidacloprid, a neonicotinoid insecticide, is commonly applied on eastern hemlock to reduce populations of Hemlock woolly adelgid (HWA). A large number of other herbivorous and transient insects also are associated with eastern hemlock. These herbivorous insects may acquire imidacloprid through feeding on treated plants. Predatory insects may acquire imidacloprid when they feed on insecticide-contaminated prey. To investigate this phenomenon, a study was conducted at Indian Boundary Campground, Cherokee National Forest, 2005-2007. This study was conducted to: 1) ascertain the effect of imidacloprid used against HWA on the predatory guild associated with eastern hemlock, 2) determine seasonal abundance of the predatory …

Survey Of Public Garden Leaders, Andrew J. Pulte

Masters Theses

Leadership and leadership development is an important topic facing those who lead and train people in the area of public horticulture. In the fall of 2007 an email survey consisting of 55 questions was sent to 448 executive directors of public gardens in the United States. This survey was divided into six major sections: demographics on each director‟s garden and their association with their garden; each directors view of leadership in their garden and in the field of public horticulture; each directors experience with, and their view on the importance of internships; leadership style; each directors level of confidence, and …

Variable Approaches Investigating Light Quality And Quantity Impacts On Warm- And Cool-Season Turfgrasses, Christian Baldwin

All Dissertations

Bermudagrass (Cynodon ssp.) is the most popular warm-season turfgrass used in warm climatic regions of the world due its recuperative ability, high traffic tolerance, heat tolerance, and relative drought and salt tolerance. However, shade is a microenvironment in which bermudagrass performs poorly. Morphological limitations, such as reduced lateral stem growth and overall reduction of carbohydrate synthesis contribute to bermudagrass, a C4 plant, decline under shade. Therefore, primary objectives of this dissertation were to determine the genetic diversity of bermudagrasses grown in full-sunlight and shade, impacts of shade and cultural practices on bermudagrass spring transition, management recommendations to enhance bermudagrass …