Life Sciences Commons^™

A Genome Wide Association Study Of Heat Tolerance In Snap Bean (Phaseolus Vulgaris), Morgan Stone

All Theses

Bean production in the United States has decreased while the temperatures have been steadily increasing, reaching new highs each year. Heat stress is detrimental to common bean (also known as snap bean) production. Symptoms of heat stress include decrease in pollen viability, shriveling of pods, and pod abortion making them unmarketable. Pod production of 323 snap bean accessions from a large diversity panel was assessed in a randomized complete block design with field trials at two different times in the spring season. The results show a significant decrease in the number of pods produced per plant and weight of pods …

Physiological And Yield Responses Of Soybean Cultivars To Heat And Drought Stresses, Sadikshya Poudel

Theses and Dissertations

Soybean (Glycine max L.) is an important legume crop often exposed to heat and drought stresses during reproductive and early-seed setting stages, resulting in lower yields and seed quality. Ten soybean cultivars were phenotyped for individual (drought or heat) and combined stress tolerance. Under drought, reduced stomatal conductance and increased canopy temperature significantly reduced seed number (46%) and weight (35%). Heat stress alone reduced seed number (19%) and weight (23%) compared to control. Moreover, a degree increase in daytime temperature above 32 °C during the reproductive stage reduced seed weight by 4% and 7% under well-watered and drought conditions, respectively. …

Non-Destructive Imaging Of Phytosulfokine Trafficking In Plants Using Fiber-Optic Fluorescence Microscopy, Bernard Abakah

Electronic Theses and Dissertations

Plants secrete peptide ligands and use receptor signaling to respond to stress and control development. Understanding these phenomena is key to improving plant health and productivity for food, fiber, and energy applications. Phytosulfokine (PSK), a sulfated peptide hormone, regulates plant cell division, growth, and stress tolerance via specific phytosulfokine receptors (PSKRs). This study uses fiber-optic fluorescence microscopy to elucidate trafficking of PSK in live plants. The microscope features two-color optics and an objective lens connected to a 1-m coherent imaging fiber mounted on either a conventional upright microscope body or 5-axis positioning system (X–Y–Z plus pitch and yaw). PSK and …

Targeted Mapping Of Oryza Sativa Chilling Tolerance Candidate Genes Using Multiple Stress-Relevant Quantitative Traits, Naoki Simon Shimoyama

Dissertations (1934 -)

Developing chilling tolerant accessions of domesticated Asian rice is a potential source of significant crop improvement to address the needs of a growing global population. The uniquely chilling sensitive nature of the tropically originating Oryza sativa make it the most important staple crop that could gain the maximum benefit from improved tolerance to low temperature stress. However, mechanisms underlying this complex trait are not fully understood. Oryza sativa has two major varietal groups with different levels of chilling tolerance, JAPONICA and INDICA, providing an ideal tool to investigate mechanistic differences in the chilling stress tolerance responses within this important crop …

Ecological Risk Assessment Of Transgenic Conditional Lethality Systems For Genetic Biocontrol Strategies, Fernan Rodrigo Perez-Galvez

Theses and Dissertations--Entomology

Genetic strategies of insect pest control are receiving increased interest due to recent advances in genetic engineering. By introducing alleles that make males functionally sterile, genetically modified (GM) insects can be used in area-wide pest management programs similar to the Sterile Insect Technique (SIT). Genetic control strategies carry several potential benefits, including improved efficacy and specificity, lower operation costs, and reduced dependence on chemical insecticides, but their use is still controversial despite extensive technical documentation indicating their innocuity to humans and the environment. This hesitation is likely due to the novel nature of the approach.

While the first field applications …

Characterization Of Sabp2-Interacting Proteins (Sip) 428: An Nad+-Dependent Deacetylase Enzyme In Plant Abiotic Stress Signaling, Oviavo Nohoesu

Electronic Theses and Dissertations

Abiotic stress leads to a change in the water content of plants. Salinity and osmotic stress affect both the morphology and physiology of plants. Plants have therefore responded to these environmental changes by adapting and tolerating them. The SABP2-interacting proteins (SIP) 428-silenced RNAi transgenic tobacco lines were subjected to various abiotic stresses (salinity, osmotic, and drought). The effect of SIP428-silencing on the tobacco plants subjected to these abiotic stresses was monitored. The results from the root growth data show that the sip428-silenced lines exhibit enhanced tolerance to the stressors compared to the wild-type plants. Interestingly, results of the relative chlorophyll …

Understanding Potassium Toxicity Stress Responses Of The Extremophyte Schrenkiella Parvula Using Systems Biology Approaches, Pramod Pantha

LSU Doctoral Dissertations

Schrenkiella parvula is an extremophyte model closely related to Arabidopsis thaliana and Brassica crops. Its natural habitat includes shores of saline lakes in the Irano-Turanian region. It has adapted to grow in soils rich in multiple salts including Na⁺ and K⁺. I have investigated the genetic basis for high K⁺ tolerance in plants using S. parvula as a stress tolerant model compared to the premier plant model, Arabidopsis thaliana which is highly sensitive to salt stresses using physiological, ionomic, transcriptomic, and metabolomic approaches. Under high K⁺ stress, root system architecture changes significantly compared to control …

Iojap: Morphological And Physiological Phenotype Characterization In Arabidopsis, Thomas Jay Payne

Doctoral Dissertations

IOJAP protein is found in all organisms that contain a ribosome of bacterial origin. The majority of studies suggest that IOJAP plays a role in translation, although this has yet to be thoroughly investigated in plants. Using Arabidopsis thaliana, an extensive phenotype characterization of iojap mutants was performed. Many processes of plant growth were slightly impaired at optimal temperature (22˚C) but became severely hindered at low temperature (12˚C and 4˚C). These cold temperature defects manifested in an overall reduction of plant growth as well as variegation, chlorosis, leaf hyponasty, as well as reduced maximum quantum yield (F_v/F …

Molecular And Physiological Assessment Of Salinity Stress Tolerance In Transgenic Arabidopsis Lines Expressing A Solanum Tuberosum Ribosome-Binding Protein, Onoud Rashed Saeed Ali Alyammahi

Biology Theses

Ribosomal proteins are highly conserved components of basal cellular organelles, primarily associated with translation of mRNA leading to protein synthesis. Additionally, some of these proteins are known to play critical role in plants RNA metabolism during stress responses, growth, and development. In this study, transgenic Arabidopsis plants expressing a ribosomal protein S27 (hereafter D26) isolated from Solanum tuberosum was subjected to NaCl-induced salinity stress conditions, to evaluate their putative stress resistance. Transgenic plants were exposed to high salinity stress, induced by 200 mM NaCl and physiological and biochemical assays were performed. The D26 transgenic plants demonstrated improved plant height and …

Plant Evolution And Urbanization: Quantifying The Effects Of Natural Selection In Shaping Shepherd’S Purse (Capsella Bursa-Pastoris) Populations In New York City, Rebecca Panko

Dissertations

The aim of this study is to quantify the effects of natural selection in shaping Capsella bursa-pastoris populations along an urban-rural gradient in New York City.

A reciprocal transplant experiment with 168 lab-germinated C. bursa-pastoris seedlings from both urban and rural populations are grown in eight paired home and away sites distributed throughout the New York metropolitan area. Sites are visited approximately thirteen times to record plant fitness. There is evidence for local adaptation of urban populations: urban plants have longer reproductive durations and produce more seed pods in urban environments. These findings suggest that urban plants are better adapted …

The Morphological, Physiological, And Genetic Underpinnings Of Intraspecific Salinity Tolerance In Sorghum Bicolor, Ashley N. Henderson

Graduate Theses, Dissertations, and Problem Reports

Decreases in land quality and quantity threaten the efficient production of agriculturally and economically pivotal crops. Such reductions in arable lands are a consequence of population growth and urbanization, and often result in the introduction of various abiotic stresses. The most common abiotic stressors include water limitation (drought), water logging (over watering), poor water quality (salinity), and extreme temperatures (cold, frost, heat). Each of these stressors negatively impact plant growth, development, and yield. Soil salinity, specifically, is a considerable constraint affecting lands used in agriculture. Salts in the soil rise both naturally and through anthropogenic factors making the abundance a …

Biochemical And Proteomic Approaches To Determine The Impact Level Of Each Step Of The Supply Chain On Tomato Fruit Quality, Robert T. Madden

USF Tampa Graduate Theses and Dissertations

Fresh fruits and vegetables (FFVs) are the most frequently wasted foods because of their perishability and handling requirements. However, there is a lack of information on how much each step of the supply chain impacts FFVs quality, particularly on tomatoes, and what measures need to be taken for an immediate and effective impact on waste reduction. There is also no information on how the supply chain affects the proteome of the tomato and what proteins are differentially regulated by the most impactful steps of the supply chain. The objectives of the work presented on this thesis were to evaluate the …

Quantitative Proteome Analysis Of Alfalfa In Drought Stress Under The Influence Of Mir156, Alpa Puri

Electronic Thesis and Dissertation Repository

Medicago sativa is one of the most produced perennial forage crops in Canada. Drought stress is a major form of abiotic stress affecting the productivity and annual yield of alfalfa. A small noncoding RNA, miR156 has a role in abiotic stress tolerance, while regulating downstream SPL genes. In this study, whole leaf proteome and amino acid concentrations of miR156OE (A8) genotype of alfalfa under drought stress were quantified. In results, 3,000 proteins groups were identified using MaxQuant when searched against Medicago truncatula protein sequence database. Gene ontology analysis showed enriched proteins were involved in biological and molecular processes such as …

Characterizing The Role Of The Mir156-Spl Network In Heat Stress Response In Medicago Sativa, Craig Matthews

Electronic Thesis and Dissertation Repository

Heat stress negatively impacts plant development by disrupting regular plant functions, including molecular, physiological and anatomical processes, reducing crop production. Alfalfa (Medicago sativa) is an important forage crop and developing abiotic stress resistant cultivars would help mitigate crop losses. Members of the miR156 family regulate SPL genes, impacting plant growth and development and are involved in stress response. Here, alfalfa with miR156 overexpression (miR156OE) and SPL13 RNAi knockdown (SPL13i) showed increased tolerance to heat stress (40°C) while SPL9 RNAi alfalfa did not. Heat-stressed miR156OE and SPL13i plants had increased antioxidant levels, including anthocyanins. Additionally, …

Synthesis, Oxidation, And Distribution Of Polyphenols In Strawberry Fruit During Cold Storage, Katrina E. Kelly

USF Tampa Graduate Theses and Dissertations

Plants inherently produce polyphenols (i.e., antioxidants) as a response to reduce oxidative stress caused by abusive environmental pre- and postharvest conditions. These antioxidants, as well as vitamin C, are present in considerable levels in strawberries; however, excessive oxidative stress brought on by improper postharvest handling conditions can reduce the levels of antioxidants in the fruit and shorten the shelf-life of strawberries. Nevertheless, it may be possible to utilize strawberry’s naturally occurring polyphenols to reduce postharvest stress and extend their shelf life. The polyphenolic profile has been previously investigated in several strawberry cultivars, however no studies have determined the unique polyphenolic …

Evaluation Of The Water Stress-Inducible Promoter Wsi18 In The Model Monocot Brachypodium Distachyon, Patrick D. Langille

Electronic Thesis and Dissertation Repository

Water deficit-inducible promoters that function in multiple species are valuable components for engineering stress-tolerant crops. Wsi18 is a water deficit-inducible promoter native to Oryza sativa. In this study, Brachypodium distachyon (B. distachyon) was used to determine if Wsi18 retained its water deficit-inducible characteristics in another monocot. Transgenic B. distachyon plants, in which the Wsi18 promoter drove the expression of the uidA reporter gene, were developed and exposed to osmotic stress generated by mannitol, salt stress conditions, and the water deficit-signaling phytohormone abscisic acid (ABA). GUS histochemical assays demonstrated increased uidA expression in the leaves and stem of …

Trascriptome Analysis Reveals Genes Commonly Induced By Botrytis Cinerea Infection, Cold, Drought And Oxidative Stresses In Arabidopsis Thaliana, Ahmed Dawood Al-Azzawi Al-Azzawi

Theses

Signaling pathways controlling biotic and abiotic stress responses may interact synergistically or antagonistically. To identify the similarities and differences among responses to diverse stresses, we analyzed previously published microarray data on the transcriptomic responses of Arabidopsis thaliana to infection with Botrytis cinerea (a biotic stress), and to cold, drought, and oxidative stresses (abiotic stresses). Our analyses showed that at early stages after B. cinerea inoculation, 1498 genes were up-regulated (B. cinerea up-regulated genes; BUGs) and 1138 genes were down-regulated (B. cinerea down-regulated genes; BDGs). We showed a unique program of gene expression was activated in response each biotic and abiotic …

Transcriptomes Analysis Reveals Genes Commonly Induced By Botrytis Cinerea Infection, Cold, Drought And Oxidative Stresses In Arabidopsis Thaliana, Ahmed Dawood Al-Azzawi

Theses

Signaling pathways controlling biotic and abiotic stress responses may interact synergistically or antagonistically. To identify the similarities and differences among responses to diverse stresses, we analyzed previously published microarray data on the transcriptomic responses of Arabidopsis thaliana to infection with Botrytis cinerea (a biotic stresses). Our analyses showed that at least at early stages B. cinerea inoculation, 1498 genes were up-regulated (B. cinerea up-regulated genes; BUGS) and 1138 genes were down-regulated (B. cinerea down-regulated genes; BUG_S). We showed a unique program of gene expression was activated in response each biotic and abiotic stress, but that …

Identification, Cloning, And Expression Of Tobacco Responsive To Dehydration Like Protein (Rd22), Sbip-355 And Its Role In Sabp2 Mediated Sa Pathway In Plant Defense, Hanadi Abdulaali Almazroue

Electronic Theses and Dissertations

Abscisic acid (ABA) induces RD22, responsive to dehydration stress gene. Salicylic acid (SA) has been the focus of research due to its role against pathogens and abiotic stress. Interaction between ABA and SA signaling pathways is still poorly understood. SA-Binding Protein 2 (SABP2) converts methyl salicylate to SA. An attempt was made to identify proteins that interact with SABP2 using a yeast 2-hybrid screening. Several interactors were identified. One of them, SA-Binding Protein 2 Interacting Protein-355 (SBIP-355), showed high homology to RD22. Bioinformatic approaches showed that SBIP-355 contains a BURP domain. Phylogenetic analysis reveals that SBIP-355 clustered into the …

Identification Of The Transcriptional Co-Repressor Complex And Its Functions In Arabidopsis Thaliana, Barsha Shrestha

University of New Orleans Theses and Dissertations

No abstract provided.

Epigenetics Of Stress Adaptation In Arabidopsis: The Case Of Histone Modifications, Behnaz Najafi Majdabadi Farahani

Electronic Thesis and Dissertation Repository

Changes in the epigenetic status of plants, which contribute to changes in gene expression, in response to abiotic stress are well documented. However, their stability and transmission to subsequent generations, and their incorporation into plant stress adaptation are still a matter for debate. Using chromatin immuno-precipitation and Next Generation Sequencing (ChIP-seq), we compared genome wide enrichment of two histone marks, H3K9ac and H3K4me2, in the progeny of salt stressed and control Arabidopsis plants. Data showed less enrichment of the H3K9ac in the chromatin of the progeny of salt stressed plants, but no changes were detected in the enrichment of the …

Meta-Analysis Of Wheat Qtl Regions Associated With Heat And Drought Stress, Marlovi Andrea Acuna Galindo

Graduate Theses and Dissertations

Heat and drought are the two most important environmental constraints to wheat production globally, are often present simultaneously and will become more severe with global climate change. This presents a unique challenge to wheat scientists who must work to develop wheat cultivars that are productive and adapted to future environmental conditions. A number of recent studies have reported quantitative trait loci (QTL) associated with heat and drought tolerance, as well as QTL for stress adaptive traits such as the availability of stem carbohydrates or crop canopy temperature. The objective of this study was to perform a meta-analysis of these QTL …

Physiological Assessment Of Chenopodium Quinoa To Salt Stress, Arturo Jason Morales

Theses and Dissertations

The physiological responses to salt stress were measured in Chenopodium quinoa. In a greenhouse experiment, salt water was applied to the quinoa varieties, Chipaya and KU-2, and to the model halophyte Thellungiella halophila to assess their relative responses to salt stress. Height and weight data from a seven-week time course demonstrated that both cultivars exhibited greater tolerance to salt than T. halophila. In a growth chamber experiment, three quinoa cultivars, Chipaya, Ollague, and CICA 17 were hydroponically grown and physiological responses were measured with four salt treatments. Tissues collected from the growth chamber treatments were used to obtain …