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Measuring Flowering Phenology And Its Consequences: A Systematic Review, Samantha M. Mangum Jun 2019

Measuring Flowering Phenology And Its Consequences: A Systematic Review, Samantha M. Mangum

Graduate Theses and Dissertations

Despite growing interest in flowering phenology among ecologists, as reflected by an increase in the number of papers, there is little information on how studies typically measure and describe a plant’s flowering phenology. The focus of this study was the literature on flowering phenology and the approaches researchers have taken to quantify flowering phenology. Initially, a comprehensive description of the breath of literature on flowering phenology was produced. From there, I described the current research on flowering phenology: the year that the studies were published, the locations of the studies, and the particular biomes where the studies were performed ...


The Archaeopalynology Of Crystal River Site (8ci1), Citrus County, Florida, Kendal Jackson Oct 2016

The Archaeopalynology Of Crystal River Site (8ci1), Citrus County, Florida, Kendal Jackson

Graduate Theses and Dissertations

The Woodland-period (ca. 1000 B.C. to A.D. 1050) fisher-hunter-gatherers of the Crystal River drainage on Florida’s Big Bend Coast are well known among southeastern archaeologists for their elaborate shell mound architecture, maritime lifeway, and exotic exchange goods. Recent archaeological investigations at the Crystal River site have employed high-resolution topographic mapping, geophysical surveys, trench excavations, and coring to model the temporality of mound construction and occupation at the site; this work has set the stage for subsequent research focusing on community structure, resource extraction, and human-ecosystem dynamics. However, like many central and north peninsular Gulf Coast sites, our ...


Microscopic Characterization Of A Transposon-Induced Male-Sterile, Female-Sterile Mutant In Glycine Max L., Katherine A. Thilges Jan 2016

Microscopic Characterization Of A Transposon-Induced Male-Sterile, Female-Sterile Mutant In Glycine Max L., Katherine A. Thilges

Graduate Theses and Dissertations

A male-sterile, female-sterile mutant was identified in a transposon-tagging study in soybean (Glycine max L.). This mutant displayed abnormalities in both micro- and mega-sporogenesis, as well as gametogenesis. Vegetatively, the mutant showed no visible differences from the wild-type phenotype. Analyses of male meiotic chromosomes were done to better understand any issues that could occur to cause sterility. Wild-type and mutant anthers and ovules were cleared throughout their development, followed by confocal scanning laser microscopy to look for any abnormalities, and to determine the timing of abortion in both the male and female organs in the mutant. Additionally, scanning electron microscopy ...


Regulation Of Shoot Development In Maize Via Brassinosteroid Signaling, Gokhan Kir Jan 2015

Regulation Of Shoot Development In Maize Via Brassinosteroid Signaling, Gokhan Kir

Graduate Theses and Dissertations

Brassinosteroids (BR) are a class of phytohormones with many important roles in plant growth and development. Compared to other model organisms BR signaling is poorly understood in maize. To study BR signaling's role in maize growth and development we suppressed two members of the BR signaling pathway, BRI1 and BIN2, by RNAi approach. BLAST searches and phylogenetic analyses suggested that there are two BRI1 copies and three BRI1-like genes (BRL) homologs in maize. bri1b, which is located on chr 5, was incomplete in databases, but via subsequent cloning and sequencing was found to be an intact and expressed gene ...


Ribosomal Frameshifting Directed By A Potyvirid Sequence Motif In Diverse Translation Systems, Alice Y. Hui Jan 2015

Ribosomal Frameshifting Directed By A Potyvirid Sequence Motif In Diverse Translation Systems, Alice Y. Hui

Graduate Theses and Dissertations

The family, Potyviridae, contains a third of all known plant viruses within eight genera. The genome is translated as one large polyprotein from which ten mature proteins are proteolytically cleaved. Recently, discovery of a protein translated from an overlapping reading frame (pipo) proved essential in systemic plant infection. It is hypothesized to translate via a ribosomal frameshift, change in reading frame during the elongation phase of translation. The cryptic programmed ribosomal frameshift signal had been undetected until now because it lacks the canonical characteristics: slippery sequence, spacer sequence, and RNA secondary structure, in that order. Only one of the three ...


The Physiological Effects Of The Seed Treatment Stamina On Maize Seedling Length, Adp:O Ratios, And Respiration Rates, Katy Lynn Darrah-Wiedemeier Jan 2015

The Physiological Effects Of The Seed Treatment Stamina On Maize Seedling Length, Adp:O Ratios, And Respiration Rates, Katy Lynn Darrah-Wiedemeier

Graduate Theses and Dissertations

Zea mays L. is an important crop in the Midwest, and each year there is a push to plant earlier in the spring. Early planting can leave seeds and seedlings vulnerable to low temperature stress. Low temperature stress causes damage to maize seedlings. It has been postulated that Strobilurin fungicides have positive physiological related effects on growth and yield. The goal of this study was to determine if the strobilurin Stamina protects maize seedlings against mitochondrial damage due to low temperature stress. In this study, three seed treatments and two seed lots/hybrids were used. Treatments included: Stamina (binders plus ...


The Co2 Concentrating Mechanism And Nitrogen Starvation Effects Under Photoautotrophic Culture Conditions Of Chlamydomonas Reinhardtii Studied By High Throughput Dna Sequencing Technology, Wei Fang Jan 2015

The Co2 Concentrating Mechanism And Nitrogen Starvation Effects Under Photoautotrophic Culture Conditions Of Chlamydomonas Reinhardtii Studied By High Throughput Dna Sequencing Technology, Wei Fang

Graduate Theses and Dissertations

The green algae species Chlamydomonas reinhardtii can acclimate to varied environmental CO2 concentration through an inducible CO2 concentration mechanism (CCM). The chloroplast stroma protein gene LCIB mutant strains exhibits an "air dier" phenotype, which demonstrated the acclimations are different in these conditions. This project first used RNA-Seq to query the Chlamydomonas reinhardtii transcriptome for regulation by CO2 and by the transcription regulator CIA5 (CCM1). Massive impacts of CIA5 and CO2 on the transcriptome were observed, and genes with distinctive expression patterns presented a rich source of candidates for new CCM components.

Two second-site mutant suppressor strains of the "air dier ...


Genetic And Physiologic Analyses Of Soybean Grain Yields In Water Limited Environments, Dawn Gibson Jan 2015

Genetic And Physiologic Analyses Of Soybean Grain Yields In Water Limited Environments, Dawn Gibson

Graduate Theses and Dissertations

Increasing grain yield in soybean is an important breeding goal for plant breeders. While identification of yield QTL can result in identification of genomic regions for increasing yield, these regions are often not consistent across environments due to genetic and environment interactions. Water limitation for crop growth is one such environment in which yield QTL are not consistent. Water limitations during grain fill can be especially devastating to the final yield of a crop. The objective of this study was to identify and then map QTL in three families of recombinant inbred lines (RILs) developed from two plant introductions and ...


Host Target Genes Of The Xanthomonas Oryzae Pv. Oryzae Type Iii Effectors For Bacterial Blight In Rice, Junhui Zhou Jan 2015

Host Target Genes Of The Xanthomonas Oryzae Pv. Oryzae Type Iii Effectors For Bacterial Blight In Rice, Junhui Zhou

Graduate Theses and Dissertations

Xanthomonas oryzae pv. oryzae is the causal agent of the bacterial blight in rice, which invades the host rice plant through injecting a myriad of effector proteins through a structure called type Ⅲ secretion system, thereafter, these effectors are also called type Ⅲ effectors. There are two groups of type Ⅲ effectors: TAL (Transcription Activator-Like) effectors that specifically bind to the promoter region of particular host genes and regulate host gene transcription and Non-TAL effectors that bind to host gene products and manipulate the host immune system.

In this thesis, I present the work of three projects. First, I, and ...


The Molecular Mechanisms Of Brassinosteroid-Regulated Drought Stress Response In Arabidopsis Thaliana, Buyun Tang Jan 2015

The Molecular Mechanisms Of Brassinosteroid-Regulated Drought Stress Response In Arabidopsis Thaliana, Buyun Tang

Graduate Theses and Dissertations

Brassinosteroids (BRs) are involved in diverse developmental processes such as cell elongation, vascular differentiation, senescence and stress response. The mechanisms and regulatory networks of BR-regulated plant growth and development have been well described for the past decade with the identification of receptors, kinases and central transcription factors involved in BR signaling. Recent studies revealed BRs also extensively participated in plant response to environmental stresses, although the mechanisms of BR-regulated stress response is largely unknown. Coordination of plant growth and stress response requires integration of multiple signaling output through hormonal crosstalk. Studies of BR signaling pathway and BR-mediated physiological responses indicate ...


Water Availability As The Driving Factor Of Growth And Physiological Function Of Co-Occurring Scrub Species In Central Florida, Tammy Foster Mar 2014

Water Availability As The Driving Factor Of Growth And Physiological Function Of Co-Occurring Scrub Species In Central Florida, Tammy Foster

Graduate Theses and Dissertations

Florida scrub is a xeromorphic upland shrub community dominated by evergreen oaks that resprout after fire, occurring on moderately to excessively well-drained nutrient-poor sand. Scrub is home to several threatened and endangered animal species (e.g., Florida scrub-jay, gopher tortoise, and indigo snake) and rare and endemic plants. Urban development and agriculture has greatly reduced and fragmented scrub habitat, and because of this Florida scrub is considered one of the most endangered ecosystems in the United States. Climate change is a further threat to Florida scrub. Under a warmer and drier climate, scrub species will be exposed to more frequent ...


New Insights Into The Functional Organization Of Xyloglucan Biosynthetic Enzymes And Their Catalytic Mechanism, Yi-Hsiang Chou Jan 2014

New Insights Into The Functional Organization Of Xyloglucan Biosynthetic Enzymes And Their Catalytic Mechanism, Yi-Hsiang Chou

Graduate Theses and Dissertations

Xyloglucan (XyG) is the major hemicellulosic polysaccharide in the primary cell walls of most vascular dicotyledonous plants, and has important structural and physiological functions in plant growth and development. In Arabidopsis thaliana, a glucan synthase CSLC4, three xylosyltransferases, XXT1, XXT2, and XXT5, two galactosyltransferase, MUR3 and XLT2 and a fucosyltransferase, FUT1 synthesize xyloglucan in Golgi. The functional organization of these enzymes is not clear. To study the functional organization of these enzymes, Bimolecular Fluorescence Complementation (BiFC), in vitro pull-down assay and co-immunoprecipitation were used to elucidate the interactions among CSLC4, XXTs, MUR3, XLT2 and FUT1 proteins both in vivo and ...


Mobile Mrna: A Long Distance Signaling System In Potato, Tian Lin Jan 2014

Mobile Mrna: A Long Distance Signaling System In Potato, Tian Lin

Graduate Theses and Dissertations

Mobile mRNA is one of the most important long-distance signals in plant vascular system. They play important roles in responding to environmental cues, such as photoperiod. There are numerous studies on mobile mRNAs in plants and thousand of mRNAs have been detected in phloem sap. One of the BEL1-like genes, designated StBEL5, has transcripts that move long distance from leaf to stolon tips and enhance tuberization. However, not many mobile mRNAs have been characterized. The mechanism of the long-distance movement of mRNAs is not clear. In this dissertation, we conducted research on different levels to characterize known mobile mRNA and ...


An Investigation Of The Factors Leading To Invasion Success Of Non-Native Plants Using A System Of Native, Introduced Non-Invasive, And Invasive Eugenia Congeners In Florida, Kerry Bohl Jan 2013

An Investigation Of The Factors Leading To Invasion Success Of Non-Native Plants Using A System Of Native, Introduced Non-Invasive, And Invasive Eugenia Congeners In Florida, Kerry Bohl

Graduate Theses and Dissertations

The overwhelming majority of plant species introduced into a new range never become invasive. Consequently, identification of factors allowing the small fraction of successful invaders to naturalize, increase in abundance, and displace resident species continues to be a key area of research in invasion biology. Of the considerable number of hypotheses that have been proposed to resolve why some plant species become noxious pests, the enemy release hypothesis (ERH) is one of the most commonly cited. The ERH maintains that invasive plants succeed in a new range because they are no longer regulated by their coevolved natural enemies, and this ...


Chlorophyll Fluorescence And Thermal Stress In Archaias Angulatus (Class Foraminifera), Heidi M. Toomey Jan 2013

Chlorophyll Fluorescence And Thermal Stress In Archaias Angulatus (Class Foraminifera), Heidi M. Toomey

Graduate Theses and Dissertations

ABSTRACT

Benthic foraminifers that host algal symbionts are similar to corals in that they rely on their algal endosymbionts for their energy needs, calcify prolifically, and are sensitive to changes in environmental conditions. They are abundant in the benthos of coastal coral-reef areas and are found throughout the tropical and subtropical regions. Pulse Amplitude Modulated (PAM) chlorophyll fluorometry and chlorophyll a extraction techniques were used to quantify and compare the photosynthetic responses of the benthic foraminiferal, Archaias angulatus and their isolated endosymbionts, Chlamydomonas hedleyi, to short-term changes in temperature. Maximum quantum efficiency (Fv/Fm) and rapid light curves ...


Investigation Of Genes Involved In The Formation Of Nitrogen-Fixing Nodules In Soybean, Chichun Yang Jan 2013

Investigation Of Genes Involved In The Formation Of Nitrogen-Fixing Nodules In Soybean, Chichun Yang

Graduate Theses and Dissertations

Nodulation is an important process in legume-rhizobium symbiotic nitrogen fixation. This thesis demonstrates our investigation of genes involved in soybean nodulation.

In the first project, we studied the molecular mechanisms contributing to an abnormal-nodulation phenotype of a soybean T-DNA insertion mutant, 454-4. Genetic analysis showed that T-DNAs are integrated into two loci of 454-4 genome, nodulation signaling pathway 2 (GmNSP2a), and GmEREACTA. Since GmNSP2a is orthologous to NSP2 proteins from Medicago truncatula and Lotus japonicus that are essential for nodulation, we speculated that the abnormal nodulation phenotype of 454-4 is due to the T-DNA insertions at GmNSP2a. To test it ...


Investigating The Evolution Of Cytochromes P450 Involved In Ga Biosynthesis, Sibongile Mafu Jan 2013

Investigating The Evolution Of Cytochromes P450 Involved In Ga Biosynthesis, Sibongile Mafu

Graduate Theses and Dissertations

Vascular plants invariably contain a class II diterpene cyclase (EC 5.5.1.x), as an ent-copalyl diphosphate synthase is required for gibberellin phytohormone biosynthesis. This has provided the basis for evolution of a functionally diverse enzymatic family. A bifunctional diterpene synthase was characterized from the lycophyte Selaginella moellendorffii . The structure of its product, labda-7,13E-dien-15-ol, demonstrates that this enzyme catalyzes a novel class II diterpene cyclization reaction, and clarifies the biosynthetic origins of the family of derived natural products.

All higher plants contain kaurene oxidases (KO), which are multifunctional cytochromes P450 that catalyze oxidation at the C4α methyl, converting ...


Genomic And Genetic Studies Of Environmental Control Of Brachypodium Growth And Development, Ying Feng Jan 2013

Genomic And Genetic Studies Of Environmental Control Of Brachypodium Growth And Development, Ying Feng

Graduate Theses and Dissertations

Brachypodium distachyon has recently been established as a model for cereals and temperate grasses because of its sequenced small genome (~270M), a small stature, short life cycle, self-fertility, an efficient transformation system and particularly its diverse ecotypes. Determination of the function for each gene in the Brachypodium genome is urgently needed for utilization of this species. In this study we (1) analyze the expression of each gene involved in vernalization pathway in Brachypodium and the correlation of vernalization requirement with freezing tolerance, (2) develop a novel high-throughput RNAi method, Phi29-Amplified RNAi Construct (PARC), to construct a cold-specific RNA interference library ...


A Study Of Chloroplast Biogenesis Within Variegated Mutants Of Arabidopsis, Andrew Alexander Foudree Jan 2012

A Study Of Chloroplast Biogenesis Within Variegated Mutants Of Arabidopsis, Andrew Alexander Foudree

Graduate Theses and Dissertations

immutans(im) is a recessive Arabidopsis mutant that is involved in chloroplast biogenesis. In the absence of IMMUTANS (IM) green and white leaf sectors form. This thesis is concerned with the development of these green and white sectors and the methods used to investigate the mechanism of their formation. IM resides in the chloroplast thylakoid membrane and has been implicated in the adjustment of electron flux through the photosynthetic electron

transport chain. Without IM white sector formation occurs due to the inability of im to

produce colored carotenoids. It is still a mystery as to how green sectors are able ...


Tassels Replace Upper Ears1 Encodes A Putative Transcription Factor That Regulates Maize Shoot Architecture By Multiple Pathways, Wei Li Jan 2012

Tassels Replace Upper Ears1 Encodes A Putative Transcription Factor That Regulates Maize Shoot Architecture By Multiple Pathways, Wei Li

Graduate Theses and Dissertations

Plant shoot architecture has many features including inflorescence sex, branching and internode elongation, which is largely controlled by the activities of shoot apical meristem (SAM) and axillary meristems (AxM). The pleiotropic maize mutant tassels replace upper ears1 (tru1) shows reduced apical dominance with elongated upper shanks tipped by lateral tassels and shortened upper stem, altered tassel phenotypes with shortened tassel length and branch length, and reduced tassel branch number. To investigate the effect of tru1 on shoot architecture, morphological analysis of tru1-ws mutant was performed, including treatments of supplemental gibberellic acid (GA3), far red (FR) light and decapitation, and genetic ...


Diversifying Monoculture Crops By Incorporating Prairie Buffer Strips, Sarah Marie Hirsh Jan 2012

Diversifying Monoculture Crops By Incorporating Prairie Buffer Strips, Sarah Marie Hirsh

Graduate Theses and Dissertations

Monoculture crop production and prevailing farming practices have greatly reduced perennial plants on the landscape and nearly eliminated native Iowa prairie vegetation. The STRIPs (Science-based Trials of Row crops Integrated with Prairies) project is a watershed-scale experiment at the Neal Smith National Wildlife Refuge, in Jasper County, Iowa, US, in which strips of prairie vegetation were planted within watersheds of corn (Zea mays) and soybean (Glycine max) production to aid in soil and water conservation. The project includes 12 0.5- to 3.2-ha watersheds. Nine watersheds included buffer strips in one of three design treatments that varied the number ...


Strategies For Recombinant Protein Production In Maize, Xing Xu Jan 2012

Strategies For Recombinant Protein Production In Maize, Xing Xu

Graduate Theses and Dissertations

Maize is not only one of the world's most important crops, but it is also the first field-grown plant-based recombinant expression system developed for commercial purposes. With advantages of low cost, high yield, high protein stability, and well-developed transformation technology over other plant systems, maize is considered to be an ideal recombinant production system. However, there are three major challenges limiting the use of maize for producing recombinant proteins: 1) maize lacks mammalian-like post-translational modification ability that may be required for pharmaceutical and industrial proteins; 2) transgenic pollen containment in open-field production; and 3) low expression of recombinant products ...


Analysis Of The Function And The Regulation Of Autophagy In Arabidopsis Thaliana, Yimo Liu Jan 2012

Analysis Of The Function And The Regulation Of Autophagy In Arabidopsis Thaliana, Yimo Liu

Graduate Theses and Dissertations

Plants have developed sophisticated mechanisms to survive under adverse growth conditions. Autophagy is activated in response to multiple abiotic stresses, pathogen infection and senescence in plants. Upon induction of autophagy, portions of cytoplasm are engulfed by double membrane structures termed autophagosomes and are delivered to vacuole for degradation. Over the past decade, the identification of many autophagy-related genes in plants has greatly enhanced our molecular and physiological understanding of plant autophagy. However, the upstream regulatory components in the autophagy pathway and the function of autophagy under various stresses are still unclear. This thesis summarizes my efforts in studying the function ...


A Type Ii Metacaspase Interacts With Rps1-K-2 In Soybean And Analysis Of The Soybean Metacaspase Gene Family, James Andrew Baskett Jan 2012

A Type Ii Metacaspase Interacts With Rps1-K-2 In Soybean And Analysis Of The Soybean Metacaspase Gene Family, James Andrew Baskett

Graduate Theses and Dissertations

Soybean suffers from the root and stem rot disease caused by the oomycete pathogen, Phytophthora sojae. A series of Rps genes confer Phytophthora resistance, and have been utilized in fighting this serious disease in soybean. Earlier we reported the cloning of the coiled coil-nucleotide binding-leucine rich repeat gene, Rps1-k-2. Here we report the identification of a type II metacaspase, Gmmc11 that interacted with the coiled-coil (CC) domain of Rps1-k-2 in vivo in yeast. The interaction was verified by conducting in vitro pull down assays in unpublished work. RNA interference of Gmmc11 in cotyledons resulted in loss of Phytophthora resistance. Gmmc11 ...


Evaluation Of Polypyrimidine Tract-Binding Protein Gene Promoters In Potato (Solanum Tuberosum Cv. Désirée), Nathaniel Martin Butler Jan 2012

Evaluation Of Polypyrimidine Tract-Binding Protein Gene Promoters In Potato (Solanum Tuberosum Cv. Désirée), Nathaniel Martin Butler

Graduate Theses and Dissertations

Polypyrimidine tract-binding (PTB) proteins are RNA-binding proteins that target specific RNAs for post-transcriptional processing by binding CU-rich motifs. PTBs have established functions in a range of RNA processes including splicing, translation, stability, and long-distance transport. Six PTB-like genes identified in potato have been grouped into two clades based on homology to other known plant PTBs. StPTB1 and StPTB6 are closely related to a PTB protein discovered in pumpkin, designated CmRBP50, and contain four canonical RNA-recognition motifs. CmRBP50 is expressed in phloem tissues and functions as the core protein of a phloem-mobile RNA/protein complex. Sequence from the potato genome database ...


Structural Variation In The Maize Genome, Kai Ying Jan 2012

Structural Variation In The Maize Genome, Kai Ying

Graduate Theses and Dissertations

Whole-genome array-based comparative genomic hybridization (aCGH) was used to study structural variation between two elite maize inbred lines, B73 and Mo17. Several hundred Copy Number Variants (CNVs) as well as several thousands of Present Absent Variants (PAVs) were discovered. This high level of structural variation among haplotypes is unprecedented among higher eukaryotes. Haplotype-specific PAVs that encompass hundreds of single-copy, expressed genes may contribute to heterosis and the extraordinary phenotypic diversity of this important crop. aCGH can be also used for genotyping complex genomes, such as that of maize. Approximately 200,000 oligonucleotide probes whose hybridization signals exhibit significant differences between ...


Genetic Regulation Of Aleurone Cell Fate In Zea Mays, Gibum Yi Jan 2012

Genetic Regulation Of Aleurone Cell Fate In Zea Mays, Gibum Yi

Graduate Theses and Dissertations

The outermost layer of the endosperm is a specific cell type called the aleurone which is one of the grain quality determining factors because of its high content in lipid, minerals and high quality proteins compared to starchy endosperm. The aleurone layer is also an attractive system to study cell fate determination because of the simplicity and plasticity of aleurone cell fate. Here we report the identification of naked endosperm (nkd) genes which are involved in aleurone differentiation in maize. The nkd mutant shows defects in aleurone cell identity and has approximately 3 outer cell layers instead of the single ...


Heterogeneous Stress Response In A Clonal Invader (Imperata Cylindrica): Implications For Management, Sarah Grace Sanford Jan 2011

Heterogeneous Stress Response In A Clonal Invader (Imperata Cylindrica): Implications For Management, Sarah Grace Sanford

Graduate Theses and Dissertations

Life history traits such as growth, survival, and clonality can vary within a population. When such variation exists in a population of an invasive species, it can affect population dynamics, and if any part of the variation has a genetic basis the population can evolve in response to control regimes. Evolutionary responses to control efforts may shift the population towards a few more resilient genotypes, or towards different types in different microenvironments, depending on the scale of gene flow with respect to the patchiness of the environment. The purpose of this study is to examine whether the application of stress ...