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A Drought-Tolerant Nitrogen-Fixing Symbiont For Sustainable Soybean Production, Christian James Peterson
A Drought-Tolerant Nitrogen-Fixing Symbiont For Sustainable Soybean Production, Christian James Peterson
Biology Dissertations
Bradyrhizobia are an ideal model organism to study plant-microbe interactions due to dual lifestyles as free-living soil organisms and as endosymbionts for valuable cropping systems in agriculture. Farmers have been utilizing the Soybean-Bradyrhizobium japonicum mutualism for decades to revitalize marginal soils, increase yields, and establish a regenerative approach to farming by mitigating the use of synthetic nitrogenous fertilizers. The largest impediment to bio-fertilizer success is desiccation (e.g., drought) stress before the symbiosis can be established. Due to climate change, fluctuating high temperatures and drought occur seasonally in many growing regions and are becoming a growing concern for modern agriculture. Thus, …
Understanding The Cellular And Physiological Mechanisms Of Fertilization And Early-Stage Seed Development, Mohammad Foteh Ali
Understanding The Cellular And Physiological Mechanisms Of Fertilization And Early-Stage Seed Development, Mohammad Foteh Ali
Theses and Dissertations--Plant and Soil Sciences
Flowering plants have evolved a unique double-fertilization process. Two sperm cells fuse with two female gametophytic cells, the egg and central cells within the ovule, giving rise to the embryo and endosperm, respectively. Sperm cells in flowering plants are nonmotile and delivered in close proximity to the egg and central cells by the pollen tube. Flowering plants have established filamentous actin (F-actin) based sperm nuclear migration system for successful fertilization. Prior to fertilization, the female gamete forms a mesh-like structure of F-actin that shows constant inward movement from the plasma membrane periphery to the center of the cell where the …
The Effects Of Silver Nanoparticles On Soybean (Glycine Max) Growth And Nodulation, Paul J. Boersma
The Effects Of Silver Nanoparticles On Soybean (Glycine Max) Growth And Nodulation, Paul J. Boersma
Electronic Thesis and Dissertation Repository
Due to their antimicrobial properties, silver nanoparticles (AgNPs) have become more popular in consumer and industrial products, leading to increasing agricultural and environmental concentrations. Exposure to AgNPs could be detrimental to plants, microbes, and their symbiotic relationships. When subjected to 10 µg/mL AgNPs in a 96-well plate, growth of Bradyrhizobium japonicum USDA 110 was halted. In hydroponic culture with 2.5 µg/mL AgNPs, biomass of inoculated Glycine max (L.) Merr. was 50% of control. Axenic plants were unaffected by this dose, but growth was inhibited at higher doses, indicating that AgNPs inhibit both nodulation and growth. Nodules treated with 2.5 µg/mL …
Investigation Of The Individual Soybean Root Nodule Microbiome, Parris Mica Mayhood
Investigation Of The Individual Soybean Root Nodule Microbiome, Parris Mica Mayhood
MSU Graduate Theses
Soybean is a valuable crop that establishes a symbiotic association with nitrogen-fixing microorganisms. Previous research suggests members of the genus Bradyrhizobium are the major nitrogen-fixing inhabitants of soybean root nodules. However, results from recent studies identified the presence of other bacteria, so called non-rhizobial endophytes (NREs), inside root nodules. All previous research has pooled nodules of different plants for bacterial community analysis, but this study investigated the presence and relative abundance of rhizobia and NREs within multiple root nodules of a single plant. Three sites were selected on Kendrick Farm in Springfield, MO, where three plants and rhizosphere soil were …
Regulation Of Local Auxin Metabolism During Soybean Nodule Development, Suresh Damodaran
Regulation Of Local Auxin Metabolism During Soybean Nodule Development, Suresh Damodaran
Electronic Theses and Dissertations
Legume-rhizobia symbiosis leads to the development of secondary root organs called nodules. Rhizobia bacteria housed inside nodules assimilate atmospheric nitrogen and convert them into plant usable forms thereby reducing the need for fertilizer application in crop legumes like soybean. Nodule development is a coordinated process orchestrated by multiple plant hormones. In soybean, the auxin responsive gene expression was detected in nodule primordia and in the periphery of mature nodules, primarily in nodule vasculature. Auxin hypersensitivity reduces nodule formation in soybean and also polar auxin transport inhibition at the site of nodule development is not crucial for determinate nodule formation. Therefore, …
Identification And Characterization Of The Isoflavonoid-Specific Prenyltransferase Gene Family To Prevent Stem And Root Rot In Soybean, Arjun Sukumaran
Identification And Characterization Of The Isoflavonoid-Specific Prenyltransferase Gene Family To Prevent Stem And Root Rot In Soybean, Arjun Sukumaran
Electronic Thesis and Dissertation Repository
Soybean is one of the most predominantly grown legumes worldwide, however, one deterrent to maximizing its yield is the pathogen, Phytophthora sojae, which causes stem and root rot disease. Many strategies have been implemented to combat this pathogen such as use of pesticides and certain agricultural practices. However, these have been largely ineffective in completely preventing P. sojae infection. An alternative strategy would be to improve the innate resistance of soybean by promoting increased glyceollin production. Glyceollins are soybean-specific antimicrobial agents which are derived from the isoflavonoid branch of the general phenylpropanoid pathway. Soybeans produce 3 forms of glyceollin: …
Inheritance, Differential Expression, And Candidate Gene Analyses For Avr2 In Phytophthora Sojae, Chelsea S. Ishmael
Inheritance, Differential Expression, And Candidate Gene Analyses For Avr2 In Phytophthora Sojae, Chelsea S. Ishmael
Electronic Thesis and Dissertation Repository
Phytophthora sojae is an oomycete responsible for seed, root and stem rot of soybean plants. Managing this disease relies on growing soybean cultivars with race-specific resistance (Rps) genes that deliver complete host immunity in the presence of corresponding pathogen avirulence (Avr) effector proteins. The aims of this study were to characterize virulence towards Rps2 among different P. sojae strains, track the inheritance of this trait, and attempt to identify an Avr2 gene. Fifteen P. sojae strains were tested for virulence towards Rps2 and crosses were performed between selected virulent and avirulent strains to follow the inheritance of virulence. …
Planting The Chalcone Reductase Family Tree: Identification And Characterization Of Chalcone Reductase Genes In Soybean, Caroline Julia Sepiol
Planting The Chalcone Reductase Family Tree: Identification And Characterization Of Chalcone Reductase Genes In Soybean, Caroline Julia Sepiol
Electronic Thesis and Dissertation Repository
Soybean (Glycine max [L.] Merr) is an important crop grown in Canada, generating $2.4 billion in sales. Though this number may be promising, soybean farmers lose about $50 million worth of yield annually due to root and stem rot disease caused by Phytophthora sojae. Many strategies have been developed to combat the infection; however, these methods are prohibitively expensive. A ‘cost effective’ approach to this problem is to select a trait naturally found in soybean that can increase resistance. One such trait is the increased production of root glyceollins. One of the key enzymes exclusively involved in glyceollin …
Identification Of Cyclophilin Gene Family In Soybean And Characterization Of Gmcyp1, Hemanta Raj Mainali
Identification Of Cyclophilin Gene Family In Soybean And Characterization Of Gmcyp1, Hemanta Raj Mainali
Electronic Thesis and Dissertation Repository
I identified members of the Cyclophilin (CYP) gene family in soybean (Glycine max) and characterized the GmCYP1, one of the members of soybean CYP. CYPs belong to the immunophilin superfamily with peptidyl-prolyl cis-trans isomerase (PPIase) activity. PPIase catalyzes the interconversion of the cis- and trans-rotamers of the peptidyl-prolyl amide bond of peptides. After extensive data mining, I identified 62 different CYP genes in soybean (GmCYP1 to GmCYP62), of which 8 are multi-domain proteins and 54 are single domain proteins. At least 25% of the GmCYP genes are expressed in soybean. GmCYP1 …
Analysis Of A Wound-Induced Gene Family In Glycine Max, Gena Robertson
Analysis Of A Wound-Induced Gene Family In Glycine Max, Gena Robertson
Masters Theses
Gene families in plants are important in understanding genome evolution indicating when and where genome duplications and segmental duplications occurred as well as subsequent divergence and subfunctionalization. A gene family in Glycine max that encodes a WI12 protein, wound-induced protein, was found to consist of ten genes on five chromosomes. Wound-induced proteins are activated in response to wounding in plants, and the WI12 protein in particular is thought to be involved in cell wall modifications at the wound site. A variety of bioinformatics tools have been used to analyze the expansion of this family in soybean as well as identify …
Analysis Of The Effects Of Hypogeal And Epigeal Emergence On Seedling Competition In Legumes, Keith E. King
Analysis Of The Effects Of Hypogeal And Epigeal Emergence On Seedling Competition In Legumes, Keith E. King
McCabe Thesis Collection
Seedling emergence is either hypogeal or epigeal. In hypogeal emergence the cotyledons remain below the soil surface during seedling development, while in epigeal emergence the cotyledons extend above the soil surface due to elongation of the hypocotyl. Here we examine the effect of seed size, and emergence type, on seedling growth. Six legumes with variation in seed size and either epigeal or hypogeal emergence were grown under dark and light conditions. A competition study was also conducted where a hypogeal and epigeal legume were grown in combination with wheat and ryegrass. Legumes expressing epigeal emergence were cowpea (Vigna unguiculata), mung …