Open Access. Powered by Scholars. Published by Universities.®

Biochemistry, Biophysics, and Structural Biology Commons

Open Access. Powered by Scholars. Published by Universities.®

Plant Sciences

Institution
Keyword
Publication Year
Publication
Publication Type
File Type

Articles 1 - 30 of 495

Full-Text Articles in Biochemistry, Biophysics, and Structural Biology

A Systems Biology Approach Toward Understanding Seed Composition In Soybean, Ling Li, Manhoi Hur, Joon-Yong Lee, Wenxu Zhou, Zhihong Song, Nick Ransom, Cumhur Yusuf Demirkale, Daniel S. Nettleton, Mark E. Westgate, Zebulun Wayne Arendsee, Vidya Vaancheeswaran Iyer, Jacqueline V. Shanks, Basil Nikolau, Eve Wurtele Jun 2019

A Systems Biology Approach Toward Understanding Seed Composition In Soybean, Ling Li, Manhoi Hur, Joon-Yong Lee, Wenxu Zhou, Zhihong Song, Nick Ransom, Cumhur Yusuf Demirkale, Daniel S. Nettleton, Mark E. Westgate, Zebulun Wayne Arendsee, Vidya Vaancheeswaran Iyer, Jacqueline V. Shanks, Basil Nikolau, Eve Wurtele

Dan Nettleton

Background

The molecular, biochemical, and genetic mechanisms that regulate the complex metabolic network of soybean seed development determine the ultimate balance of protein, lipid, and carbohydrate stored in the mature seed. Many of the genes and metabolites that participate in seed metabolism are unknown or poorly defined; even more remains to be understood about the regulation of their metabolic networks. A global omics analysis can provide insights into the regulation of seed metabolism, even without a priori assumptions about the structure of these networks.

Results

With the future goal of predictive biology in mind, we have combined metabolomics, transcriptomics, and ...


Induction Of Ethylene Inhibits Development Of Soybean Sudden Death Syndrome By Inducing Defense-Related Genes And Reducing Fusarium Virguliforme Growth, Noor A. Abdelsamad, Gustavo C. Macintosh, Leonor F.S. Leandro May 2019

Induction Of Ethylene Inhibits Development Of Soybean Sudden Death Syndrome By Inducing Defense-Related Genes And Reducing Fusarium Virguliforme Growth, Noor A. Abdelsamad, Gustavo C. Macintosh, Leonor F.S. Leandro

Biochemistry, Biophysics and Molecular Biology Publications

Ethylene is a gaseous hormone that regulates plant responses to biotic and abiotic stresses. To investigate the importance of ethylene in soybean resistance to Fusarium virguliforme (Fv), the causal agent of sudden death syndrome (SDS), soybean cultivars Williams 82 (SDS-susceptible) and MN1606 (SDS-resistant) were treated 24 h before and 24h after Fv inoculation with either ethephon (ethylene inducer), cobalt chloride (ethylene biosynthesis inhibitor), or 1-MCP (ethylene perception inhibitor). Inoculated plants were grown for 21 days at 24°C in the greenhouse and then evaluated for SDS severity and expression of soybean defense genes. In both cultivars, plants treated with ethephon ...


Extraction And Quantification Of Hydrolyzable Tannins In Acorns From Different Species Of Oak Trees (Quercus Spp.), Sarah Browning, Marshall E. Woodruff Apr 2019

Extraction And Quantification Of Hydrolyzable Tannins In Acorns From Different Species Of Oak Trees (Quercus Spp.), Sarah Browning, Marshall E. Woodruff

Undergraduate Research Conference

Do white-tailed deer (Odocoileus virginianus) prefer to eat certain types of acorns based on tannin content?

Hydrolyzable tannins consist of gallate groups connected via ester linkages to a carbohydrate (D-glucose)

The Prussian Blue method was used to determine hydrolyzable tannin content


Purification And Characterization Of A Nonspecific Lipid Transfer Protein 1 (Nsltp1) From Ajwain (Trachyspermum Ammi) Seeds, Meshal Nazeer, Humera Waheed, Maria Saeed, Saman Yousuf Ali, M. Iqbal Choudhary, Zaheer Ul-Haq, Aftab Ahmed Mar 2019

Purification And Characterization Of A Nonspecific Lipid Transfer Protein 1 (Nsltp1) From Ajwain (Trachyspermum Ammi) Seeds, Meshal Nazeer, Humera Waheed, Maria Saeed, Saman Yousuf Ali, M. Iqbal Choudhary, Zaheer Ul-Haq, Aftab Ahmed

Pharmacy Faculty Articles and Research

Ajwain (Trachyspermum ammi) belongs to the family Umbelliferae, is commonly used in traditional, and folk medicine due to its carminative, stimulant, antiseptic, diuretic, antihypertensive, and hepatoprotective activities. Non-specific lipid transfer proteins (nsLTPs) reported from various plants are known to be involved in transferring lipids between membranes and in plants defense response. Here, we describe the complete primary structure of a monomeric non-specific lipid transfer protein 1 (nsLTP1), with molecular weight of 9.66 kDa, from ajwain seeds. The nsLTP1 has been purified by combination of chromatographic techniques, and further characterized by mass spectrometry, and Edman degradation. The ajwain nsLTP1 is ...


Development Of An Innovative And Sustainable One-Step Method For Rapid Plant Dna Isolation For Targeted Pcr Using Magnetic Ionic Liquids, Arianna Marengo, Cecilia Cagliero, Barbara Sgorbini, Jared L. Anderson, Miranda N. Emaus, Carlo Bicchi, Cinzia M. Bertea, Patrizia Rubiolo Mar 2019

Development Of An Innovative And Sustainable One-Step Method For Rapid Plant Dna Isolation For Targeted Pcr Using Magnetic Ionic Liquids, Arianna Marengo, Cecilia Cagliero, Barbara Sgorbini, Jared L. Anderson, Miranda N. Emaus, Carlo Bicchi, Cinzia M. Bertea, Patrizia Rubiolo

Chemistry Publications

Background

Nowadays, there is an increasing demand for fast and reliable plant biomolecular analyses. Conventional methods for the isolation of nucleic acids are time-consuming and require multiple and often non-automatable steps to remove cellular interferences, with consequence that sample preparation is the major bottleneck in the bioanalytical workflow. New opportunities have been created by the use of magnetic ionic liquids (MILs) thanks to their affinity for nucleic acids.

Results

In the present study, a MIL-based magnet-assisted dispersive liquid–liquid microextraction (maDLLME) method was optimized for the extraction of genomic DNA from Arabidopsis thaliana (L.) Heynh leaves. MILs containing different metal ...


Using Publicly Available Genbank Data To Teach Plant Phylogeny In High School Classrooms, Madhav P. Nepal, Ethan J. Andersen Feb 2019

Using Publicly Available Genbank Data To Teach Plant Phylogeny In High School Classrooms, Madhav P. Nepal, Ethan J. Andersen

iLEARN Teaching Resources

In this teaching module, students will learn about NCBI GenBank, search for DNA/protein sequences from multiple plant species of a gene that encodes Rubisco enzyme, construct and interpret a phylogenetic tree, and discuss traits that allowed plants to adapt their life on land.


Ultrastructural Analysis Of The Digestive Gland Secretory And Absorptive Processes In Nepenthes Glandulifera, Shannon Manuel Jan 2019

Ultrastructural Analysis Of The Digestive Gland Secretory And Absorptive Processes In Nepenthes Glandulifera, Shannon Manuel

Biochemistry, Cellular and Molecular Biology Honors Papers

Nepenthes glandulifera is a carnivorous pitcher plant native to tropical environments, of which the majority live on the islands in the Malay Archipelago where sunlight and water are abundant. The pitcher trap style contains a modified pitfall trap that attracts insects and other small invertebrates through various attractive mechanisms. These plants also contain digestive glands that secrete digestive fluid to break down prey into nutrients for the plant. The digestive fluid, with remarkably unique properties, has been analyzed in relation to multiple areas of study including the development of an enzyme-supplementation strategy for the treatment of celiac disease and the ...


Disease Resistance In Wheat And Its Relatives, Ethan James Andersen Jan 2019

Disease Resistance In Wheat And Its Relatives, Ethan James Andersen

Electronic Theses and Dissertations

Plants have evolved a complex defense system against pests and pathogens utilizing many types of receptors, signaling factors, and defense compounds to detect pathogen presence and respond effectively. Since many pathogens have evolved immunesuppressing effectors used to reduce plant resistance, plants have evolved a family of receptors that detect pathogenic effectors as a result of an evolutionary arms race. These receptors contain Nucleotide-Binding Site and Leucine-Rich Repeat domains and are called NBS-LRR or NLR proteins. Many grasses possess huge genomes with hundreds of NLR-encoding genes, often found in clusters at the extra-pericentromeric regions of chromosomes, where unequal crossing over causes ...


Epidemiological Studies Of Soybean Vein Necrosis Virus And Potential Resistance Mechanisms To Its Vector Neohydatothrips Variabilis (Beach), Jing Zhou Dec 2018

Epidemiological Studies Of Soybean Vein Necrosis Virus And Potential Resistance Mechanisms To Its Vector Neohydatothrips Variabilis (Beach), Jing Zhou

Theses and Dissertations

Soybean (Glycine max (L.) Merrill) is one the most important crops in global agriculture with annual production of over 260 million metric tons. As the dependence of a growing global population to soybean has increased, so does the importance of soybean diseases and pests. Over 200 pathogens attack soybean; among them, viruses pose a major threat to the soybean industries accounting for approximately 10% of the annual yield reduction caused by diseases in the past two decades. Soybean vein necrosis virus (SVNV) is a relatively newly discovered virus causing the homonymous disease. The widespread occurrence of the disease in major ...


A Simple Metabolic Switch May Activate Apomixis In Arabidopsis Thaliana, David Alan Sherwood Dec 2018

A Simple Metabolic Switch May Activate Apomixis In Arabidopsis Thaliana, David Alan Sherwood

All Graduate Theses and Dissertations

Apomixis, asexual or clonal seed production in plants, can decrease the cost of producing hybrid seed and enable currently open pollinated crops to be converted to more vigorous and higher yielding hybrids that can reproduce themselves through their own seed. Sexual reproduction may be triggered by a programmed stress signaling event that occurs in both the meiocyte, just prior to meiosis, and later in the egg just prior to embryo sac maturation. The prevention of stress signaling and the activation of a pro-growth signal prior to meiosis triggered apomeiosis, the first half of apomixis. The same approach was used prior ...


Molecular Fossils From Phytoplankton Reveal Secular Pco2 Trend Over The Phanerozoic, Caitlyn R. Witkowski, Johan W. H. Weijers, Brian S. Blais, Stefan Schouten, Jaap S. Sinninghe Damsté Nov 2018

Molecular Fossils From Phytoplankton Reveal Secular Pco2 Trend Over The Phanerozoic, Caitlyn R. Witkowski, Johan W. H. Weijers, Brian S. Blais, Stefan Schouten, Jaap S. Sinninghe Damsté

Science and Technology Faculty Journal Articles

Past changes in the atmospheric concentration of carbon dioxide (PCO2) have had a major impact on earth system dynamics; yet, reconstructing secular trends of past PCO2 remains a prevalent challenge in paleoclimate studies. The current long-term PCO2reconstructions rely largely on the compilation of many different proxies, often with discrepancies among proxies, particularly for periods older than 100 million years (Ma). Here, we reconstructed Phanerozoic PCO2 from a single proxy: the stable carbon isotopic fractionation associated with photosynthesis (Ɛp) that increases as PCO2 increases. This concept has been widely applied to alkenones, but here, we expand ...


Spatial Mapping And Profiling Of Metabolite Distributions During Germination, Adam D. Feenstra, Liza E. Alexander, Zhihong Song, Andrew R. Korte, Marna D. Yandeau-Nelson, Basil J. Nikolau, Young-Jin Lee Nov 2018

Spatial Mapping And Profiling Of Metabolite Distributions During Germination, Adam D. Feenstra, Liza E. Alexander, Zhihong Song, Andrew R. Korte, Marna D. Yandeau-Nelson, Basil J. Nikolau, Young-Jin Lee

Robbyn Anand

Germination is a highly complex process by which seeds begin to develop and establish themselves as viable organisms. In this paper, we utilize a combination of GC-MS, LC-fluorescence, and mass spectrometry imaging (MSI) approaches to profile and visualize the metabolic distributions of germinating seeds from two different inbreds of maize seeds, B73 and Mo17. GC and LC analyses demonstrate that the two inbreds are highly differentiated in their metabolite profiles throughout the course of germination, especially with regard to amino acids, sugar alcohols, and small organic acids. Crude dissection of the seed followed by GC-MS analysis of polar metabolites also ...


A Third Class: Functional Gibberellin Biosynthetic Operon In Beta-Proteobacteria, Raimund Nagel, John E. Bieber, Mark G. Schmidt-Dannert, Ryan S. Nett, Reuben J. Peters Nov 2018

A Third Class: Functional Gibberellin Biosynthetic Operon In Beta-Proteobacteria, Raimund Nagel, John E. Bieber, Mark G. Schmidt-Dannert, Ryan S. Nett, Reuben J. Peters

Biochemistry, Biophysics and Molecular Biology Publications

The ability of plant-associated microbes to produce gibberellin A (GA) phytohormones was first described for the fungal rice pathogen Gibberella fujikuroi in the 1930s. Recently the capacity to produce GAs was shown for several bacteria, including symbiotic alpha-proteobacteria (α-rhizobia) and gamma-proteobacteria phytopathogens. All necessary enzymes for GA production are encoded by a conserved operon, which appears to have undergone horizontal transfer between and within these two phylogenetic classes of bacteria. Here the operon was shown to be present and functional in a third class, the beta-proteobacteria, where it is found in several symbionts (β-rhizobia). Conservation of function was examined by ...


Direct Determination Of The Site Of Addition Of Glucosyl Units To Maltooligosaccharide Acceptors Catalyzed By Maize Starch Synthase I, Ying Xie, Adam W. Barb, Tracie A. Hennen-Bierwagen, Alan M. Myers Aug 2018

Direct Determination Of The Site Of Addition Of Glucosyl Units To Maltooligosaccharide Acceptors Catalyzed By Maize Starch Synthase I, Ying Xie, Adam W. Barb, Tracie A. Hennen-Bierwagen, Alan M. Myers

Biochemistry, Biophysics and Molecular Biology Publications

Starch synthase (SS) (ADP-glucose:1,4-α-D-glucan 4-α-D-glucosyltransferase) elongates α-(1→4)-linked linear glucans within plastids to generate the storage polymers that constitute starch granules. Multiple SS classes are conserved throughout the plant kingdom, indicating that each provides a unique function responsible for evolutionary selection. Evidence has been presented arguing for addition of glucosyl units from the ADPglucose donor to either the reducing end or the non-reducing end of the acceptor substrate, although until recently direct evidence addressing this question was not available. Characterization of newly incorporated glucosyl units determined that recombinant maize (Zea mays L.) SSIIa elongates its substrates ...


Lipid Transport Required To Make Lipids Of Photosynthetic Membranes, Evan Labrant, Allison C. Barnes, Rebecca Roston Jun 2018

Lipid Transport Required To Make Lipids Of Photosynthetic Membranes, Evan Labrant, Allison C. Barnes, Rebecca Roston

Biochemistry -- Faculty Publications

Photosynthetic membranes provide much of the usable energy for life on earth. To produce photosynthetic membrane lipids, multiple transport steps are required, including fatty acid export from the chloroplast stroma to the endoplasmic reticulum, and lipid transport from the endoplasmic reticulum to the chloroplast envelope membranes. Transport of hydrophobic molecules through aqueous space is energetically unfavorable and must be catalyzed by dedicated enzymes, frequently on specialized membrane structures. Here, we review photosynthetic membrane lipid transport to the chloroplast in the context of photosynthetic membrane lipid synthesis. We independently consider the identity of transported lipids, the proteinaceous transport components, and membrane ...


Direct Production Of Dihydroxylated Sesquiterpenoids By A Maize Terpene Synthase, Jin Liang, Jiang Liu, Reid Brown, Meirong Jia, Ke Zhou, Reuben J. Peters, Qiang Wang Jun 2018

Direct Production Of Dihydroxylated Sesquiterpenoids By A Maize Terpene Synthase, Jin Liang, Jiang Liu, Reid Brown, Meirong Jia, Ke Zhou, Reuben J. Peters, Qiang Wang

Biochemistry, Biophysics and Molecular Biology Publications

The astounding structural and biological diversity of the large class of terpenoid natural products are imparted by both their complex hydrocarbon backbones and further elaboration by the addition of multiple hydroxyl groups, which provide both solubility and specific binding properties. While the role of terpene synthases in generating hydrocarbons with complex backbones is well known, these also are known to generate (singly) hydroxylated products by the addition of water prior to terminating deprotonation. Here a maize sesquiterpene synthase was unexpectedly found to generate dually hydroxylated products directly from (E,E)-farnesyl diphosphate, primarily eudesmane-2,11-diol, along with two closely related ...


Agronomic And Chemical Performance Of Field-Grown Tobacco Engineered For Triterpene And Methylated Triterpene Metabolism, Zuodong Jiang, Chase Kempinski, Santosh Kumar, Scott Kinison, Kristin Linscott, Eric Nybo, Sarah Janze, Constance Wood, Joseph Chappell Jun 2018

Agronomic And Chemical Performance Of Field-Grown Tobacco Engineered For Triterpene And Methylated Triterpene Metabolism, Zuodong Jiang, Chase Kempinski, Santosh Kumar, Scott Kinison, Kristin Linscott, Eric Nybo, Sarah Janze, Constance Wood, Joseph Chappell

Pharmaceutical Sciences Faculty Publications

Squalene is a linear intermediate to nearly all classes of triterpenes and sterols and is itself highly valued for its use in wide range of industrial applications. Another unique linear triterpene is botryococcene and its methylated derivatives generated by the alga Botryococcus braunii race B, which are progenitors to fossil fuel deposits. Production of these linear triterpenes was previously engineered into transgenic tobacco by introducing the key steps of triterpene metabolism into the particular subcellular compartments. In this study, the agronomic characteristics (height, biomass accumulation, leaf area), the photosynthetic capacity (photosynthesis rate, conductance, internal CO2 levels) and triterpene content ...


Characterizing Virus-Induced Gene Silencing At The Cellular Level With In Situ Multimodal Imaging, Sadie J. Burkhow, Nicole M. Stephens, Yu Mei, Maria Emilia Duenas, Daniel J. Freppon, Geng Ding, Shea C. Smith, Young-Jin Lee, Basil J. Nikolau, Steven A. Whitham, Emily A. Smith May 2018

Characterizing Virus-Induced Gene Silencing At The Cellular Level With In Situ Multimodal Imaging, Sadie J. Burkhow, Nicole M. Stephens, Yu Mei, Maria Emilia Duenas, Daniel J. Freppon, Geng Ding, Shea C. Smith, Young-Jin Lee, Basil J. Nikolau, Steven A. Whitham, Emily A. Smith

Chemistry Publications

Background: Reverse genetic strategies, such as virus-induced gene silencing, are powerful techniques to study gene function. Currently, there are few tools to study the spatial dependence of the consequences of gene silencing at the cellular level.

Results: We report the use of multimodal Raman and mass spectrometry imaging to study the cellular-level biochemical changes that occur from silencing the phytoene desaturase (pds) gene using a Foxtail mosaic virus (FoMV) vector in maize leaves. The multimodal imaging method allows the localized carotenoid distribution to be measured and reveals differences lost in the spatial average when analyzing a carotenoid extraction of the ...


Cloning And Characterization Of A Pyrethroid Pesticide Decomposing Esterase Gene, Est3385, From Rhodopseudomonas Palustris Psb-S, Xiangwen Luo, Deyong Zhang, Xuguo Zhou, Jiao Du, Songbai Zhang, Yong Liu May 2018

Cloning And Characterization Of A Pyrethroid Pesticide Decomposing Esterase Gene, Est3385, From Rhodopseudomonas Palustris Psb-S, Xiangwen Luo, Deyong Zhang, Xuguo Zhou, Jiao Du, Songbai Zhang, Yong Liu

Entomology Faculty Publications

Full length open reading frame of pyrethroid detoxification gene, Est3385, contains 963 nucleotides. This gene was identified and cloned based on the genome sequence of Rhodopseudomonas palustris PSB-S available at the GneBank. The predicted amino acid sequence of Est3385 shared moderate identities (30–46%) with the known homologous esterases. Phylogenetic analysis revealed that Est3385 was a member in the esterase family I. Recombinant Est3385 was heterologous expressed in E. coli, purified and characterized for its substrate specificity, kinetics and stability under various conditions. The optimal temperature and pH for Est3385 were 35 °C and 6.0, respectively. This enzyme could ...


Searching For Potential Binding Partners Of Arabidopsis Β-Amylase9 Using Yeast 2-Hybridization, Sheikh Hossain May 2018

Searching For Potential Binding Partners Of Arabidopsis Β-Amylase9 Using Yeast 2-Hybridization, Sheikh Hossain

Senior Honors Projects, 2010-current

In plants, starch is a major carbon and energy storage compound. Starch is made as a product of photosynthesis while plants are in light and is degraded at night. Our lab is interested in the cellular mechanism of starch degradation in plants and for our studies we use Arabidopsis thaliana as a model. β-amylases are primarily responsible for the hydrolysis of starch in plants and a total of nine β-amylases genes are encoded in Arabidopsis thaliana. These nine genes are identified as BAM1-9. BAM9 is located in the chloroplast where starch is located, and is present is all ...


The Heart Of The Madder: An Important Prehistoric Pigment And Its Botanical And Cultural Roots, Michelle Laberge May 2018

The Heart Of The Madder: An Important Prehistoric Pigment And Its Botanical And Cultural Roots, Michelle Laberge

Theses and Dissertations

In recent years, an interest in natural botanical dye sources has prompted new research into the cultivation and processing of prehistoric dye plants. Advances in chemical analyses of ancient European textiles have provided more information about dye plants such as woad (Isatis tinctoria) weld (Reseda luteola) and madder (Rubia tinctorum), which were important sources of color in early textile production. Evidence of madder dye has been reported in the archaeological record of the European Bronze and Iron Ages in textiles preserved in the Hallstatt salt mines, Scandinavian bog sites and other elite European burials but the picture of madder usage ...


The Effects Of Gibberellic Acid And Auxin Hormones On Heliotropism In Sunflowers, Brandon Bernardo, Hagop S. Atamian May 2018

The Effects Of Gibberellic Acid And Auxin Hormones On Heliotropism In Sunflowers, Brandon Bernardo, Hagop S. Atamian

Student Scholar Symposium Abstracts and Posters

Sunflowers are one of many different plant species that are able to track and face the sun in order to optimize the amount of sunlight they are exposed to. This process of orienting towards the sun is called Heliotropism. Sunflowers are able to effectively orient themselves towards the sun because the growth rate on the East and West side of the stem alternates depending on the time of day. At dawn, the East facing stem will grow at a faster rate than the West facing side, resulting in the flower orienting towards the West. This alternating and uneven growth is ...


Inferring Roles In Defense From Metabolic Allocation Of Rice Diterpenoids, Xuan Lu, Juan Zhang, Benjamin Brown, Riqing Li, Julio Rodríguez-Romero, Aileen Berasategui, Bo Liu, Meimei Xu, Dangping Luo, Zhiqiang Pan, Scott R. Baerson, Jonathan Gershenzon, Zhaohu Li, Ane Sesma, Bing Yang, Reuben J. Peters May 2018

Inferring Roles In Defense From Metabolic Allocation Of Rice Diterpenoids, Xuan Lu, Juan Zhang, Benjamin Brown, Riqing Li, Julio Rodríguez-Romero, Aileen Berasategui, Bo Liu, Meimei Xu, Dangping Luo, Zhiqiang Pan, Scott R. Baerson, Jonathan Gershenzon, Zhaohu Li, Ane Sesma, Bing Yang, Reuben J. Peters

Biochemistry, Biophysics and Molecular Biology Publications

Among their responses to microbial infection, plants deploy an arsenal of natural antibiotic products. Historically these have been identified on the basis of their antibiotic activity in vitro, which leaves open the question of their relevance to defense in planta. The vast majority of such natural products from the important crop plant rice (Oryza sativa) are diterpenoids whose biosynthesis proceeds via either ent- or syn-copalyl diphosphate (CPP) intermediates, which were isolated on the basis of their antibiotic activity against the fungal blast pathogen Magnaporthe oryzae. However, rice plants in which the gene for the syn-CPP synthase Os-CPS4 is ...


Roles Of Phospholipases And Ribosomal S6 Kinase In Lipid Remodeling And Growth In Arabidopsis Response To Phosphate Deprivation, Yuan Su Apr 2018

Roles Of Phospholipases And Ribosomal S6 Kinase In Lipid Remodeling And Growth In Arabidopsis Response To Phosphate Deprivation, Yuan Su

Dissertations

Phosphate (Pi) is one of three macronutrients for plants, which is vital for plant growth and development. Understanding the mechanism by which plants respond and adapt to Pi deficiency not only unveils functions of genes and pathways involved, but also provides potential tools to manipulate crops to better stand Pi stress in low Pi-containing lands. One of the significant metabolic changes in plants under Pi starvation is the membrane lipid remodeling that converts Pi-containing lipids such as phospholipids to Pi-free lipids, such as glycolipids. To elucidate the metabolism and regulation of lipid remodeling, this dissertation characterizes the role of two ...


Constitutive Expression Of Thioglucoside Glucohydrolase 1 (Tgg1) Decreases Intercellular Trafficking In Arabidopsis Thaliana, Alessandro Francesco Sarno Apr 2018

Constitutive Expression Of Thioglucoside Glucohydrolase 1 (Tgg1) Decreases Intercellular Trafficking In Arabidopsis Thaliana, Alessandro Francesco Sarno

EURēCA: Exhibition of Undergraduate Research and Creative Achievement

Plasmodesmata (PD) are pores that traverse plant cell walls, providing a route for intercellular trafficking of essential metabolites, nutrients, and signaling molecules between adjacent plant cells, thereby aiding communication. The increased size exclusion limit 2 (ise2) mutant of Arabidopsis thaliana has an increased abundance of branched PD, as well as a greater flux of intercellular trafficking. A search for proteins that interact with ISE2 identified THIOGLUCOSIDE GLUCOHYDROLASE 2 (a myrosinase). A. thaliana also encodes a second, closely-related myrosinase, TGG1. Myrosinases are enzymes that catalyze the hydrolysis of glucosinolates, a type of secondary metabolite that are amino acid derivatives. The breakdown ...


Evaluation Of Controlled-Release Nitrogen And Potassium Fertilizer In Louisiana Sugarcane Production, Samuel Kwakye Apr 2018

Evaluation Of Controlled-Release Nitrogen And Potassium Fertilizer In Louisiana Sugarcane Production, Samuel Kwakye

LSU Master's Theses

Sugarcane (Saccharum spp) production is an integral part of Louisiana's economy. Proper fertilizer management, particularly nitrogen (N) and potassium (K), optimizes sugarcane production. An experiment was established in 2015 at the LSU AgCenter Sugar Research Station in St. Gabriel, Louisiana to: (1) assess the effect of N and K fertilizer sources on sugarcane yield and quality parameters, and (2) monitor the changes in inorganic N and K levels in the soil at different sugarcane growth stages. The experiment was arranged in a randomized complete block design on a Sharkey clay soil and complete randomized design on a Commerce silt ...


Heterotrophic N2-Fixation Contributes To Nitrogen Economy Of A Common Wetland Sedge, Schoenoplectus Californicus, Eliska Rejmankova, Dagmara Sirova, Stephanie T. Castle, Jiri Barta, Heather Carpenter Apr 2018

Heterotrophic N2-Fixation Contributes To Nitrogen Economy Of A Common Wetland Sedge, Schoenoplectus Californicus, Eliska Rejmankova, Dagmara Sirova, Stephanie T. Castle, Jiri Barta, Heather Carpenter

Environmental Studies Faculty Publications and Presentations

A survey of the ecological variability within 52 populations of Schoenoplectus californicus (C.A. Mey.) Soják across its distributional range revealed that it is commonly found in nitrogen (N) limited areas, but rarely in phosphorus limited soils. We explored the hypothesis that S. californicus supplements its nitrogen demand by bacterial N2-fixation processes associated with its roots and rhizomes. We estimated N2-fixation of diazotrophs associated with plant rhizomes and roots from several locations throughout the species’ range and conducted an experiment growing plants in zero, low, and high N additions. Nitrogenase activity in rhizomes and roots was ...


Proteasome Storage Granules Protect Proteasomes From Autophagic Degradation Upon Carbon Starvation, Richard S. Marshall, Richard D. Vierstra Apr 2018

Proteasome Storage Granules Protect Proteasomes From Autophagic Degradation Upon Carbon Starvation, Richard S. Marshall, Richard D. Vierstra

Biology Faculty Publications & Presentations

26S proteasome abundance is tightly regulated at multiple levels, including the elimination of excess or inactive particles by autophagy. In yeast, this proteaphagy occurs upon nitrogen starvation but not carbon starvation, which instead stimulates the rapid sequestration of proteasomes into cytoplasmic puncta termed proteasome storage granules (PSGs). Here, we show that PSGs help protect proteasomes from autophagic degradation. Both the core protease and regulatory particle sub-complexes are sequestered separately into PSGs via pathways dependent on the accessory proteins Blm10 and Spg5, respectively. Modulating PSG formation, either by perturbing cellular energy status or pH, or by genetically eliminating factors required for ...


Functions Of Maize Genes Encoding Pyruvate Phosphate Dikinase In Developing Endosperm, Ryan R. Lappe, John W. Baier, Susan K. Boehlein, Ryan Huffman, Qiaohui Lin, Fabrice Wattebled, A. Mark Settles, L. Curtis Hannah, Ljudmilla Borisjuk, Hardy Rolletschek, Jon D. Stewart, M. Paul Scott, Tracie A. Hennen-Bierwagen, Alan M. Myers Jan 2018

Functions Of Maize Genes Encoding Pyruvate Phosphate Dikinase In Developing Endosperm, Ryan R. Lappe, John W. Baier, Susan K. Boehlein, Ryan Huffman, Qiaohui Lin, Fabrice Wattebled, A. Mark Settles, L. Curtis Hannah, Ljudmilla Borisjuk, Hardy Rolletschek, Jon D. Stewart, M. Paul Scott, Tracie A. Hennen-Bierwagen, Alan M. Myers

Agronomy Publications

Maize opaque2 (o2) mutations are beneficial for endosperm nutritional quality but cause negative pleiotropic effects for reasons that are not fully understood. Direct targets of the bZIP transcriptional regulator encoded by o2 include pdk1 and pdk2 that specify pyruvate phosphate dikinase (PPDK). This enzyme reversibly converts AMP, pyrophosphate, and phosphoenolpyruvate to ATP, orthophosphate, and pyruvate and provides diverse functions in plants. This study addressed PPDK function in maize starchy endosperm where it is highly abundant during grain fill. pdk1 and pdk2 were inactivated individually by transposon insertions, and both genes were simultaneously targeted by endosperm-specific RNAi. pdk2 accounts for the ...


Using Genomic And Gene Expression Methods To Understand The Phenotypic Response Of Soybean To Sudden Death Syndrome Caused By Fusarium Virguliforme, Alexander Stephen Luckew Jan 2018

Using Genomic And Gene Expression Methods To Understand The Phenotypic Response Of Soybean To Sudden Death Syndrome Caused By Fusarium Virguliforme, Alexander Stephen Luckew

Graduate Theses and Dissertations

Soybean sudden death syndrome (SDS) is one of the most important soybean diseases in the Midwestern United States, leading to average losses of $396 million per year from 1996 to 2015. The causal agent of SDS, soilborne fungus Fusarium virguliforme (Fv), causes root rot symptoms and releases phytotoxins taken up by the plant to produce chlorosis and necrosis in the leaves. The main management practice used to reduce the impact of SDS is planting resistant soybean cultivars. Resistance to SDS is known to be quantitative with 88 known quantitative trait loci (QTL) based on Soybase.org. Many of these QTL ...