Symposium Proceedings

 

Poster Session G: 

4:00 - 5:00 pm

Entomology and Plant Pathology; Environmental Science; Horticulture and Landscape Architecture; Microbiology and Molecular Genetics; Nutritional Sciences; Plant and Soil Sciences; and Plant Biology, Ecology, and Evolution (42 posters)

 

Presentations:

 

G-01     Connor Huffstetter

Research Collaborators:  Indira Priyadarshini Lakkakula, Rajat Sharma, Finn Bergbower, Meriem Aoun

Research Presentation Title:  Evaluation of a hard winter wheat germplasm to leaf rust and stripe rust

Faculty Research Mentor:  Meriem Aoun, Entomology and Plant Pathology

 

Leaf rust, caused by Puccinia triticina (Pt), and stripe rust, caused by Puccinia striiformis f. sp. tritici (Pst), are significant threats to wheat production worldwide. Developing resistant varieties remains the most effective strategy for managing rust diseases. To identify potential sources of leaf rust and stripe rust resistance in hard winter wheat, we assembled a diverse panel of 320 accessions comprising wheat breeding lines and varieties from various breeding programs across the U.S. Great Plains. This germplasm was evaluated at the seedling stage in controlled greenhouse conditions against five prevalent Pt races in the U.S., including MPPSD, MNPSD, MBDSD, MJBJG, and TNBJS. The five races have different avirulence/virulence phenotypes to characterized leaf rust resistance genes in wheat. Additionally, seedling evaluations were conducted in the growth chamber against PSTv-37, which is the most common Pst race in the U.S. Our leaf rust evaluations revealed varying frequencies of resistance in this germplasm among Pt races. Only 18% and 30% of the wheat accessions exhibited resistance to the Pt races MNPSD and MPPSD, respectively. The Pt race MBDSD was the least virulent as 72% of the accessions were resistant. We found that 43% and 47% of the accessions were resistant against races TNBJS and MJBJG, respectively. A total of 21 accessions (7%) showed a broad spectrum of resistance to all five Pt races. Seedling resistance to stripe rust against race PSTv-37 was very limited in this germplasm collection, with only 7% of the accessions displaying resistance. The identified sources of leaf rust and stripe rust resistance within this germplasm hold promise for enhancing rust resistance breeding in wheat. Ongoing research to understand the genetic basis underlying rust resistance in these accessions could further inform and speed breeding efforts in developing resistant varieties.

 

G-02     Ethan Shaw

Research Collaborators:  Noha Youssef, Emma Mills, Amelea Jones

Research Presentation Title:  Determining DNA Differences: Using PCR to Determine the Genetic Material in Deltochilum gibbosum Fed on Either Dung or Carrion

Faculty Research Mentor:  Wyatt Hoback, Entomology and Plant Pathology

 

Dung beetles of the subfamily Scarabaeinae are notable for their coprophagous, or dung eating, behavior. They feed on animal dung as adults, use the resource as a part of reproduction, and when their eggs hatch the larvae feed on that dung as well. However, a species of dung beetle native to Oklahoma is just as comfortable using animal matter, such as fur, feathers, and carrion, as they are using dung. Deltochilum gibbosum, the humpbacked dung beetle, is a large (> 2 cm) dung beetle that displays this feeding behavior. A beetle that can perform the ecosystem service of nutrient recycling using both dung and carrion is not only ecologically important but is also valuable to cattle operations looking to keep their pastures healthy. Since Deltochilum gibbosum can utilize both dung and carrion, they would need to have a gut microbiome suited for both resources. However, the microbiome of these beetles has never been examined. We acquired eight Deltochilum gibbosum, four male and four female, from the Insect Adventure. Two of the males and two of the females were fed on pig dung, while the other beetles were fed using dead laboratory mice. After staying on their target diet for a period of four weeks, the beetles were dissected, and their guts were preserved in a freezer in ethanol. The DNA was extracted using a DNeasy Plant Pro Kit and the associated process. A PCR test will be performed on the extracted DNA. This data will allow us to get an idea of the microbiome of these beetles while also determining if there are any differences between the beetles fed on dung and those fed on carrion. We hypothesize that the microbiome of Deltochilum gibbosum fed on carrion will be different than the microbiome of those fed on dung.

 

G-03     Reese Trujillo

Research Collaborators:  M. Driever, Peña Zuniga, R. Ruschel Kanotz, F. Ochoa Corona

Research Presentation Title:  Virome-viroid Complexity of Cut-Flower Chrysanthemums in Oklahoma

Faculty Research Mentor:  Francisco Ochoa Corona, Entomology and Plant Pathology

 

Fragile X Syndrome (FXS) is a neurodevelopmental disorder and a primary genetic cause of autism. It is caused by a gene mutation and common symptoms include auditory hypersensitivity. In noisy environments, binaural hearing is used to determine sound source locations, which can be particularly difficult for individuals with FXS. FXS is hypothesized to originate from an imbalance in neural exhibition and inhibition, a key component of the ability to localize sounds, leading to a lesser ability to function in these hectic environments. In our project, we use a mouse model of FXS to better understand how FXS is affecting auditory sound localization ability. With the use of a reflexive behavioral paradigm, we can gain information regarding the FXS mouse’s response to sound. By using varying sound stimuli, we will test the mice’s prepulse inhibition (PPI) and acoustic startle response (ASR)1 . Ultimately, mice with FXS show delayed hearing development along with a lesser ability to inhibit a startle response. These issues may be seen around 12-14 days old (hearing onset begins) and 21 days old (another critical time point in auditory development). By studying mice with FXS, we can pinpoint when and how hearing development is affected and relate our findings to developmental delays seen in humans.

 

G-04     Audrey Hardgrave

Research Collaborators:  Scotland Souders

Research Presentation Title:  Changes in Manganese Concentrations in Acid Mine Drainage through Passive Treatment Systems

Faculty Research Mentor:  Julie LaBar, Environmental Science

 

Passive treatment systems are used across the United States to treat water contaminated by mine drainage. One possible part of these systems is Vertical Flow Bioreactors (VFBRs), which aim to remove trace metals from acid mine drainage. However, while these do effectively decrease these concentrations, manganese concentrations can be very unpredictable for unknown reasons. Since many trace metals can be toxic through bacterial sulfate reduction to environments in large concentrations, we must find out what causes these changes. The goal of this project is to reenact what occurs within VFBRs to try to determine was causes the differences in manganese concentrations. We are conducting this by duplicating the environment which typically occurs in a VFBR. We partially filled cubitainers with spent mushroom compost, a substrate often used in VFBRs, and filled them with simulated mine drainage. We regularly measure the conductivity, pH, dissolved oxygen, oxygen-reduction potential, temperature, and manganese concentrations of the cubitainers. This experiment is ongoing but a few changes in the cubitainers have been observed thus far. The results we obtain by examining the changes in water quality aim to determine what causes the changes in manganese concentrations and further clean water of toxins created by human activities. These results will help us ascertain how we can improve passive treatment systems in the future to effectively and consistently decrease manganese concentrations in acid mine drainage and therefore improve the quality of life around polluted water resources. 

 

G-05     Scotland Souders

Research Collaborators:  Julie LaBar

Research Presentation Title:  Passive Treatment of Mine Drainage and the Behavior of Manganese

Faculty Research Mentor:  Julie LaBar, Environmental Science

 

Non-point source pollution poses a significant threat to the environment and can be difficult to prevent and remediate. One contributor to this is mine drainage, which can contain numerous contaminants of concern. Passive treatment systems have been developed as a method of remediating mine drainage. The behavior of manganese within these systems has raised questions regarding its ability to be retained by the organic substrate used for remediation, with a prior study showing manganese sometimes being released in higher concentrations than when it entered the system. The goal of this current study is to further research on the behavior of manganese and determine if there is a pattern of its release within treatment systems. For this study, cubitainers are set up containing an organic substrate and a manganese solution. Biweekly testing is currently being conducted to measure pH, dissolved oxygen, conductivity, and oxidation-reduction potential. Along with this, samples of water from each container are being analyzed for manganese concentrations. This is an ongoing project, and samples will continue to be taken into the next academic year. At the end of the semester, three of the containers will be sacrificed to analyze the manganese content within the organic substrate itself. This information will be used to determine in which part of the substrate the manganese is retained. This will provide further insight into improving passive treatment systems for a variety of contaminants. 

 

G-06     Kristal Casey

Research Collaborators:  Lou Anella

Research Presentation Title:  Pl@ntNet App - Photographing and Identifying Herbaceous Plants for The Botanic Garden at Oklahoma State University

Faculty Research Mentor:  Lou Anella, Horticulture and Landscape Architecture

 

The research at The Botanic Garden at Oklahoma State University leverages the Pl@ntNet app, an innovative plant identification tool designed to facilitate the study of plant biodiversity through advanced image recognition technology. This collaborative initiative, developed by a consortium comprising research institutions and universities, leverages a comprehensive database of plant images and botanical data. It aims to enhance academic and public engagement with botany by providing an accessible platform for the accurate identification of plant species. By enabling users to upload photographs for identification, Pl@ntNet promotes environmental education and supports conservation efforts through the democratization of botanical knowledge. The project aimed to document and accurately identify herbaceous plant species within the 28 gardens, enhancing both garden management and the global database on plant biodiversity. Over the course of the study, 1658 photographs were taken, resulting in 261 successful submissions to Pl@ntNet, covering 173 plant species across 55 families. Utilizing a Samsung Galaxy S22 Ultra, the research captured detailed images of plants, focusing on visual characteristics essential for accurate identification. This effort not only contributed significantly to the Pl@ntNet database but also aimed at enriching visitors' understanding of plant species diversity. The challenges encountered, including managing lighting conditions and minimizing background distractions, underscore the complexities of fieldwork in botany. The project's success is a testament to the effectiveness of integrating digital tools in environmental and botanical research, contributing valuable data for conservation efforts, and enhancing educational resources within The Botanic Garden at Oklahoma State University.

 

G-07     Victoria Hughes

Research Collaborators:  Katie Stenmark, Niels Maness, Bruce Dunn

Research Presentation Title: Quality analysis of bitter acids in hops (Humulus lupulus L.) from greenhouse production systems in Oklahoma.  

Faculty Research Mentor:  Charles Fontanier, Horticulture and Landscape Architecture

 

Hop plants are produced for harvest of mature hop cones that are utilized in the medicinal, agricultural, cosmetic and craft beer industries. Hop plants are vigorously climbing perennials that require shorter than 15-hour days for flowering induction, and a trellis structure (18-20ft annual height) for seasonal support. In the United States, the majority of hops are grown in field production systems in the Pacific Northwest where summer day lengths are long. The demand for hops has increased due to a boom in the craft beer industry which has led growers in southern states to seek alternative methods for producing hops outside of their traditional commercial growing region. Hop performance in greenhouse systems has not been evaluated in Oklahoma before, but greenhouse production offers an alternative for hop producers in the south to harvest multiple crops per year. Four cultivars of hops (‘Cascade’, ‘Comet’, ‘Newport’, ‘Tahoma’) were grown using a Dutch bucket hydroponic system with one rhizome per bucket spaced 1.5ft apart without supplemental lighting in the USDA research greenhouses at Oklahoma State University. Hops were harvested by hand and dried to 7% moisture content for 48 hours at 40°C. Hop bitter acids (α-acids and β-acids) were extracted using a 0.1% formic acid solvent, and hop quality was determined by HPLC. Bitter acids were determined to be highest in cultivars ‘Comet’ (α- 2.12%, β- 0.73%), ‘Cascade’ (α- 2.00%, β- 1.04%), and ‘Tahoma’ (α- 1.92%, β- 1.23%). ‘Newport’ had a notably lower α-acid content (0.71%) but contained a higher β-acid content (0.81%) than the β-acids in ‘Comet’ hops. With the information from this research, local greenhouse growers will be able to determine if hops are a viable option for their region.  

 

G-08     Madeline Mocio

Research Collaborators:  Bruce Dunn, Amandeep Kaur, Charles Fontanier, Lu Chang

Research Presentation Title: Plant Growth, Nutrient Uptake, and Vitamin A Content of Hydroponic Mustard Greens with Supplemental Seaweed Extract.

Faculty Research Mentor:  Bruce Dunn, Horticulture and Landscape Architecture

 

Biostimulants can affect plant growth and quality in hydroponic production. Mustard greens ‘Red Splendor’ and ‘Ruby Streaks’ were grown using the ebb and flow technique with added seaweed extracts (Kelpak, CleanKelp, Liquid Seaweed). Data were collected on plant growth, foliar nutrient content, and vitamin A content. ‘Ruby Streaks’ had significantly greater vitamin A content than ‘Red Splendor’. Shoot fresh weight was significantly higher in ‘Ruby Streaks’ grown with CleanKelp extract than ‘Red Splendor’ grown with CleanKelp, Liquid Seaweed, and no supplemental extracts, and ‘Ruby Streaks’ grown with no supplemental extracts.  

 

G-09     Simon Riley

Research Collaborators:  Aaron Essary

Research Presentation Title:  Observational Study of Vitis vinifera in Perkins, Oklahoma

Faculty Research Mentor:  Aaron Essary, Horticulture and Landscape Architecture

 

Vitis Vinifera is a species of grapevine that is most commonly used in the wine industry for its wine quality. Oklahoma has a relatively small, but established wine industry that hovers around 400 acres of land for wine grape production. The objective of our study was to examine the ability of V. vinifera to grow despite the relatively unfavorable conditions, when compared to the conditions of AVAs like the Napa Vally, of Oklahoma. The experiment was conducted at the Cimmaron Valley Research Center in Perkins, Oklahoma. The varieties chosen were Cabernet Sauvignon, Mourvedre, Syrah (Shiraz), Picpoul Blanc, and Sauvignon Blanc. Of the vines the Cabernet Sauvignon vines grew an average of 21.7 in, Picpoul Blanc grew an average of 20.6 in, and Sauvignon Blanc grew and average of 17.1 in. Mourvedre and Syrah grew to an average of 27.8 in and 26.1 in respectively, however we lost 6 of 40 Mourvedre vines and 24 of 40 of our Syrah vines. We are not certain for the cause of death in these vines, but we can conclude that all the vines produced enough aboveground biomass for a sufficient amount of nutrients to be used to grow a sufficient root system to survive the winter freeze and produce berries in the third year. Further analysis is necessary to determine whether the vines will produce good quality berries and whether the deaths were a result of a limiting factor such as water, or as a result of the vines traits not being suited to handle the climate. 

 

G-10     Sam Wiesepape

Research Presentation Title:  Bermudagrass Genotypes and Their Responses to Varying Light Intensities

Faculty Research Mentor:  Charles Fontanier, Horticulture and Landscape Architecture

 

Turfgrass is crucial for golf courses and sports fields, but is faces environmental challenges, like light intensity and shade, that can hinder its growth. The research done uses the warm season bermudagrass, employing C4 photosynthesis enhancing its adaptation to summer conditions. Bermudagrass genotypes will exhibit decreased turf quality, height, and root growth when stressed by low light intensities. Mechanisms such as compound growth and root-shoot ratio help turfgrasses tolerate shade stress. This study aims to explore the photosynthetic response of different bermudagrass genotypes in response to varying light intensities and to identify the bermudagrass genotype which will maintain high performance under lower light intensity. The research involves gas exchange measurements using an LI-COR 6800 which assess photosynthesis rates under different light intensities. At the end of the data collection period, statistical analysis will include fitting the photosynthetic-light curve to a nonrectangular hyperbola model. Data collection will begin on February 16, 2024, and will be collected once a week for four to five weeks. This study will contribute valuable insights into bermudagrass responses to light variations, with potential implications for turfgrass management in diverse environmental conditions.  

 

G-11     Elyse Cronic

Research Collaborators:  Brittney Conn, Toby Nelson, Karen Wozniak

Research Presentation Title:  Identification of the Antifungal Mechanism of EIPE-1 against Cryptococcus neoformans

Faculty Research Mentor:  Karen Wozniak, Microbiology and Molecular Genetics

 

Cryptococcus neoformans is a fungal pathogen found worldwide in soil and bird droppings that can cause disease in both immunocompromised and immunocompetent hosts. Cryptococcal meningitis has received global attention and is credited with 152,000 cases of cryptococcal meningitis yearly in the HIV/AIDS population, killing approximately 112,000 people each year. Treatment options for fungal infections are limited, many treatments are toxic, and fungal organisms are becoming resistant to current treatments. Therefore, the discovery of novel antifungal therapies is critical for fighting these deadly infections. Previous studies in our lab showed that a eumelanin-inspired compound, EIPE-1, has antifungal activity against C. neoformans. EIPE-1 treatment led to misshapen cells, and transcriptional data showed differential regulation of fungal genes involved in cell wall synthesis, membrane assembly, and cell stress. Therefore, we hypothesized that fungal strains with mutations in these signaling pathways will be resistant to EIPE-1 treatment. For this, we have screened mutants from the C. neoformans mutant library for those that are available for transcription factors, kinases, and phosphatases. Mutants were mixed in a competition with an m-cherry fluorescent cryptococcal strain and treated with the MIC concentration of EIPE-1 or were left untreated as a control. Following a 24h incubation, cells were analyzed on a flow cytometer to evaluate resistant mutants. Data show that the mutants tested are more susceptible to  EIPE-1 treatment than wild-type cryptococcal cells. Additional studies will examine further mutants to uncover those more resistant to EIPE-1 treatment. Future studies will verity these data by incubating the mutant strains with increasing concentrations of EIPE-1, which will verify their importance in resistance to EIPE-1. Finally, we will examine the how EIPE-1 interacts with the signaling pathway(s) where these genes are located by Western blot to examine phosphorylation of proteins in the identified pathways. These studies will enable us to pinpoint the mechanism of action of EIPE-1 against C. neoformans.  

 

G-12     Clauddia Dodd

Research Collaborators:  Ramee Aranda

Research Presentation Title:  Defining Upstream Protein Kinases of Atypical MAPKs in Dictyostelium discoideum

Faculty Research Mentor:  Jeff Hadwiger, Microbiology and Molecular Genetics

 

Background: MAPKs, or mitogen-activated protein kinases, are found in eukaryotic organisms and usually play important roles in signal transduction pathways and gene regulation. MAPKs are usually regulated by MAPK kinases (MAP2Ks), which will phosphorylate the MAPK to make it active and MAP2Ks are also regulated by phosphorylation. Research has shown that one subgroup of MAPKs, found only in organisms with cell movement, are not phosphorylated by conventional MAP2Ks and this group has been referred to as atypical MAPKs. In Dictyostelium, Erk2 is an atypical MAPK that is not phosphorylated by a conventional MAP2K and so we assume it is phosphorylated by another type of protein kinase. Dictyostelium. Through rigorous research, Erk2 was shown to be essential for chemotactic responses (the movement of cells to a chemical signal), including those important in foraging for food sources and multicellular development. In a recent study, researchers identified many proteins that are phosphorylated during chemotactic responses and one of these is likely to be the protein kinase that regulates Erk2 activation. However, determining which protein kinase regulates Erk2 must still be determined. Thus, the proposed project is to take significant steps toward discovering the protein kinase that phosphorylates Erk2.

G-13     Emma England

Research Collaborators:  Carrie Pratt, Mostafa Elshahed, Noha Youssef

Research Presentation Title:  Evaluating the Impact of Redox Potential on Growth Capacity of Anaerobic Gut Fungi

Faculty Research Mentor:  Noha Youssef, Microbiology and Molecular Genetics

 

Anaerobic gut fungi (AGF), members of the phylum Neocallimastigomycota, play a key role in plant biomass degradation in the alimentary tracts of herbivores. These fungi could potentially play a role in biofuel production, a process that would require fungal growth at a large scale. Understanding the aerotolerance abilities of AGF is essential to the scaling of this process. AGF are strict anaerobes, a trait regarded as an adaptation for survival in the oxygen-devoid herbivorous gut, however, some studies have shown that multiple AGF taxa could survive transient exposure to oxygen. This study evaluated the capacity of four genera of AGF to survive at three different redox potentials (-200mv, -100mV, and 0mV). Redox potential was controlled by varying the concentration of reductant (cysteine hydrochloride), and growth was measured by quantifying gas accumulation in the headspace. All strains tested exhibited growth at -200mV and -100mV, while no growth was observed at or above 0mV. Our results establish an upper limit for AGF growth under different redox potentials, indicate a similar response of multiple AGF taxa to redox potential variation, and suggest that loss of the ability to grow under high redox conditions (0 mV and above) is a common ancestral trait in the phylum Neocallimastigomycota.   

 

G-14     Gracie Faver

Research Collaborators:  Erica Lutter

Research Presentation Title:  Detection and characterization of rifampicin-resistant Staphylococcus aureus small colony variants

Faculty Research Mentor:  Yingxin Chang, Microbiology and Molecular Genetics

 

Staphylococcus aureus is an opportunistic pathogen that frequently causes infections in the lungs and other mucoid-rich regions of cystic fibrosis (CF) patients. Small colony variants (SCV) of S. aureus are a subpopulation of bacteria that are often found in chronically infected airways of CF patients. The development of SCVs is due to the adaptation of S. aureus to antibiotic treatment, thus SCVs are usually associated with chronic and relapsing infections. To characterize the phenotypic traits of clinical S. aureus SCVs isolated from CF patients in Oklahoma, S. aureus strains were isolated from sputum samples collected from patients at the Oklahoma Cystic Fibrosis Clinic at the OU Children’s Hospital in Oklahoma City. Twenty-seven S. aureus clinical isolates were plated on Mannitol Salt Agar (MSA), followed by the enrichment and screening of SCVs with a low concentration gentamycin. Out of 27 S. aureus clinical isolates, seven were found to form SCVs, two of which were resistant to rifampicin. The plating of serial dilutions onto Tryptic Soy Agar (TSA) showed SCV formation rates ranging from 12.5% to 50%.  SCVs compared to the original strains also exhibited differences in growth rates. Further aims of this project include investigating biofilm formation, determining auxotrophism for thymidine, hemin and menadione, and examining rpoB gene mutations to characterize the phenotypic traits and genetic variations of rifampicin resistant S. aureus SCVs. This will be the first study providing information about S. aureus SCVs in CF patients located in Oklahoma. Discovering the intricate patterns and traits of these SCVs allows healthcare professionals to better recognize the evolution of S. aureus in CF patients, and potentially formulate better treatment and management strategies. 

 

G-15     Jonathan Lee

Research Collaborators:  Reed Stubbendieck

Research Presentation Title:  Stress Inducing Acids on Moraxella catarrhalis

Faculty Research Mentor:  Reed Stubbendieck, Microbiology and Molecular Genetics

 

Moraxella catarrhalis is a bacterium commonly found in the upper respiratory tract of children. Although it is harmless in a healthy host, it may be responsible for ear infections, sinus infections, pneumonia, and bronchitis in an immunocompromised host. Moraxella catarrhalis was found to be highly resistant to antibiotics. This project aims to find a new drug to inhibit M. catarrhalis. We ran multiple inhibition assay experiments using lactic acid to investigate the minimum inhibitory concentration (MIC) of Moraxella catarrhalis. The next part of the project is to co-culture Dolosigranulum pigrum and M. catarrhalis. These two bacteria have a negative association because D. pigrum is a commensal lactic acid bacterium. The lactic acid production of D. pigrum will be measured to determine if it produces sufficient lactic acid to inhibit M. catarrhalis.

G-16     Jacob Lieberman

Research Collaborators:  Timothy Hubin

Research Presentation Title:  Antifungal Activity of Novel Macrocycle Derivatives on Cryptococcus neoformans

Faculty Research Mentor:  Karen Wozniak, Microbiology and Molecular Genetics

 

Cryptococcus neoformans is an opportunistic fungal pathogen that causes cryptococcosis. After inhalation, the organism disseminates to the brain, where it causes cryptococcal meningitis. Annually, approximately 225,000 immunocompromised individuals develop cryptococcal meningitis, resulting in over 181,000 deaths. To treat these patients, there are only four classes of antifungals currently available, and these options are toxic and ineffective. In addition, fungal pathogens are becoming resistant to existing antifungals. In the current study, we are testing the antifungal activity of macrocycle compounds, developed by our collaborator, against C. neoformans. These compounds have been shown to be active against many other fungal pathogens, allowing us to hypothesize that these compounds would exhibit antifungal activity against C. neoformans. We first tested 12 macrocycle compounds against C. neoformans strain H99. After incubating each compound at different concentrations with H99, the minimum inhibitory concentration (MIC) was calculated. Compounds exhibiting antifungal activity were then tested for cytotoxicity using the mouse macrophage cell line J774.A. Effective, non-toxic compounds were then assayed with existing antifungal drugs in checkerboard assays to determine possible synergistic or antagonistic activity. The majority of the compounds showed antifungal activity. Of these compounds, 6 were non-toxic. Initial checkerboard assays have shown synergistic and indifferent interactions between the tested compounds and antifungal drugs.  Future studies will focus on identifying the mechanism of action of these compounds. Confocal and electron microscopy will be used to identify changes in fungal cell wall & membrane morphology, and screening of mutant libraries will be used to identify mutants resistant to these compounds.  

 

G-17     Ella McReynolds

Research Collaborators:  Noha Youssef, Mostafa Elshahed

Research Presentation Title:  An exploration into how habitat transition impacted the evolutionary trajectory and genomic repertoire of the phylum Acidobacteriota

Faculty Research Mentor:  Noha Youssef, Microbiology and Molecular Genetics

 

The phylum Acidobacteriota is one of the most ecologically successful lineages on earth. Its members are present in a wide range of environments but are extremely successful in soil. The goal of this project is to determine, through a comparative genomics approach, the characteristics that render Acidobacteriota successful in their respective environments, with specific emphasis on soil- vs. non-soil-dwelling groups. We are currently analyzing 2028 publicly available Acidobacteriota genomes. General genomic features are currently being compared between families in context of their ecological preferences. It is predicted that certain qualities advantageous to a soil environment such as those to engage in biological warfare (antibiotic resistance and production) and those to increase adaptability to an ever-changing environment (pH, optimal growth temperature, presence of CRISPRs and viral genomes) will be enriched in soil-dwelling lineages of Acidobacteriota. All predicted proteins from 811 genomes (belonging to 9 families) were clustered into protein families. Preliminary ordination analysis based on the protein family clusters grouped genomes based on their phylogenetic affiliation (50.4% of variance explained, p-value=0.001), but showed that habitat preference and the interaction between phylogeny and habitat also significantly (p-value=0.001) explained 1.99% and 3.23% of variances. Both phylogenomic and phylogenetic trees placed these families in distinct clades based on their preferred habitat. We are currently expanding analysis of predicted proteins with plans to analyze protein clusters gained or lost at each family node, allowing us to pinpoint gained functions that allowed successful transition to soil habitats

 

G-18     Olivia Morgan

Research Collaborators:  Somalisa Pan, Matthew Cabeen

Research Presentation Title:  PtsN, a component of the nitrogen-related phosphotransferase system, is a newfound regulator of the T3SS in Pseudomonas aeruginosa

Faculty Research Mentor:  Matthew Cabeen, Microbiology and Molecular Genetics

 

The opportunistic pathogen Pseudomonas aeruginosa (PA) poses a growing health concern as it frequently causes nosocomial infections and exhibits resistance to antimicrobial therapeutics. Transcriptomic data revealed that the protein PtsN, a component of the nitrogen-related phosphotransferase system (Nitro-PTS) in PA, differentially regulates genes involved in the type III secretion system (T3SS). The T3SS is a substantial factor in the virulence of P. aeruginosa. Located in the inner membrane, the T3SS is used to assemble an apparatus that can act as a syringe to secrete effector proteins into the cytoplasm of host cells. These effector proteins negatively impact the host immune response and allow for better survival of the bacteria. In strains deleted for ptsN, we observe a substantial upregulation in T3SS gene expression. The T3SS has a well-established regulatory network, wherein the presence of an environmental signal triggers a partner switching mechanism that unbinds ExsA, the master activator of T3SS gene expression, from an anti-activator. To better understand its involvement in T3SS expression, we deleted ptsN in strains with constitutively inactive or active T3SS expression. We saw that the absence of PtsN could not recover T3SS expression in a constitutively inactive state but was able to further enhance expression of a constitutively active system. We hypothesize that PtsN may interact with ExsA in a way that limits the ability of ExsA to activate T3SS genes and are now testing this idea using co-immunoprecipitation.

 

G-19     Jake Patterson

Research Collaborators:  Hollis Holcomb, Erika Lutter

Research Presentation Title:  Identification of an Antivirulence Signal Produced by Pseudomonas aeruginosa Clinical Isolates

Faculty Research Mentor:  Erika Lutter, Microbiology and Molecular Genetics

 

Pseudomonas aeruginosa is a bacterium that is associated with chronic infections in Cystic Fibrosis patient’s lungs. Pseudomonas can cause an infection that slowly and progressively damages the lungs and intermittently spikes in severity (an exacerbation) doing considerable damage to the host’s lungs before returning to its more chronic state. This research focuses on a Pseudomonas clinical isolate that produces a signal that makes other Pseudomonas isolates less virulent. Pseudomonas is often associated with multi-drug resistance. Alternative, non-antibiotic, treatment options may pave the way for Pseudomonas infection control and treatment. We hypothesized that the signal producing isolate secretes a protein or peptide that dampens virulence factors in receptive Pseudomonas aeruginosa isolates. The goal of this study was to isolate, identify, and characterize this secreted signal. The signal producing Pseudomonas culture was grown in liquid media to harvest the signal containing supernatant (all the liquid outside of the cells) and concentrated it by centrifugation. This was necessary for the second step: separating proteins within the concentrated supernatant through Size Exclusion Chromatography (SEC). SEC separates proteins based on size into fractions. Using these fractions, a plate-based casein degradation assay developed by our lab was performed to detect protease production. The results suggested that the signal was a protein or peptide and gave the approximate size of the signal based on when the fractions eluted during SEC. The fractions containing the strongest antivirulence effect, in addition to adjacent fractions lacking the ability to inhibit protease production, were sent for mass spectrometry analysis. The results provided a list of putative proteins that were only present or significantly higher in concentration in the fractions that inhibited virulence. This list in tandem with the estimated size of the signal from SEC was used to generate a brief list of strong candidates for the signal's identity. 

 

G-20     Megan Roach

Research Collaborators:  Benjamin Nelson, Savannah Beakley, Karen Wozniak

Research Presentation Title:  Antifungal Mechanisms of Action by Dendritic Cell Lysosome Proteins

Faculty Research Mentor:  Karen Wozniak, Microbiology and Molecular Genetics

 

Cryptococcus neoformans is an opportunistic fungal pathogen that primarily affects immunocompromised individuals and can cause cryptococcal meningitis. Approximately 152,000 cases of cryptococcal meningitis occur annually in HIV/AIDS patients, leading to 112,000 yearly deaths. Very few antifungal drugs are available to treat cryptococcal infection, and those are ineffective or toxic. In addition, fungal pathogens such as C. neoformans have become resistant to many types of treatment. Previous studies in our lab showed that proteins from the dendritic cell (DC) lysosome have antifungal activity against C. neoformans, including NOSTRIN, human neutrophil elastase (HNE), matrix metalloproteinase 25 (MMP25), myeloperoxidase (MPO), and coronin. In this study, we tested the antifungal activity of the compound NOSTRIN, one of the DC lysosomal proteins that has been known to exhibit these antifungal properties. We tested NOSTRIN against the C. neoformans strain H99 using different concentrations of the drug and calculated the minimum inhibitory concentration (MIC). Then, fluorescence microscopy was used to examine structural changes in C. neoformans following treatment. Results showed that NOSTRIN had a similar result compared to MICs performed with the antifungal drug Amphotericin B, with NOSTRIN around 0.25 ug/ml and Amphotericin B around 2 ug/ml. In addition, fluorescence microscopy showed that fungal cells treated with NOSTRIN are releasing intracellular contents following incubation, indicating damage to the fungal cell wall or membrane. In future studies, we will continue to examine NOSTRIN and other antifungal DC lysosome proteins by microscopy and using cryptococcal mutant libraries in order to identify their mechanism(s) of antifungal activity. By researching the presented topics, we hope to gain a better understanding of the effects that these proteins have on C. neoformans, which could potentially lead to more effective therapies for cryptococcosis. 

 

G-21     Will Stewart

Research Collaborators:  Niloy Kumar Das

Research Presentation Title:  Purification of Bacillus subtilis kinase protein RsbT for antibody preparation

Faculty Research Mentor:  Matthew Cabeen, Microbiology and Molecular Genetics

 

The bacterium Bacillus subtilis uses a 1.8 MDa protein complex called a stressosome to sense environmental stressors such as ethanol and salt and activate the alternative sigma factor σB accordingly. A stressosome complex is composed of 40 copies of four different RsbR paralogs and 20 copies of the scaffold protein RsbS, which together sequester up to 20 copies of RsbT. Recent work in our lab uncovered the new finding that RsbT can sense environmental stress even in the absence of a stressosome. This led us to create strains of B. subtilis that contain. RsbT, are deleted for RsbT, or have controllable levels of RsbT. To test the possibility that RsbT can sense stress on its own, we are also expressing RsbT and its downstream signaling proteins in Escherichia coli. For all this work, to validate whether RsbT is properly folding inside of those strain or relative abundance of RsbT, an RsbT antibody is a key tool. To raise such an antibody, we were required to recombinantly express and then purify the RsbT protein . The cloning of rsbT was done using pET47b and the construct was expressed in E. coli BL21 under an IPTG-inducible promoter. Once expressed in E.coli, the RsbT protein was purified on a Ni-NTA column, and the His tag was cleaved from RsbT during dialysis with 3C protease. Finally, we carried out size-exclusion chromatography to isolate the purified RsbT protein and verified its purity by SDS-PAGE before sending it for antibody production in rabbits. 

 

G-22     Rebecca Wilson

Research Collaborators:  Noopur Dasgupta, Chelsea Murphy

Research Presentation Title:  Investigating Mechanisms of Antibiotic Resistance in Microbes from Cystic Fibrosis Patients

Faculty Research Mentor:  Erika Lutter, Microbiology and Molecular Genetics

 

Cystic fibrosis (CF) is a lethal genetic disease, characterized by polymicrobial lung infections that are near impossible to treat due to the high level of antibiotic resistance of the pathogens. Though the multi-drug resistance of pathogens has been previously documented, the mechanisms for antibiotic resistance acquisition are still largely unknown. A prior screen of CF sputa identified the most resistant and multidrug-resistant bacterial candidates. This project aimed to identify the MICs and MBCs against antibiotics used in CF treatment at the time of sample collection for several bacterial isolates with subsequent genome sequencing to determine the genetic basis for their resistance mechanisms. Each isolate was tested in an MIC broth dilution assay with various concentrations of each antibiotic to determine the minimum amount needed to inhibit the growth of each isolate, then plated to determine the minimum concentration to kill the isolate.  Genomic DNA was isolated and sequenced with the genomes assembled by external company, SeqCenter. With collaboration from a bioinformatics specialist, the assembled genomes were searched for genes known to confer resistance mechanisms to the antibiotics screened for. Results indicate that resistant microbes including Staphylococcus aureus and fungi are able to persist in CF lung despite aggressive antibiotic treatment. 

 

G-23     Lorelei Winton

Research Collaborators:  Myriam Achour, Jacob Burch-Konda

Research Presentation Title: The role of calcium sensor EfhP in regulating pyoverdine production in a human pathogen, Pseudomonas aeruginosa.

Faculty Research Mentor:  Marianna Patrauchan, Microbiology and Molecular Genetics

 

Pseudomonas aeruginosa (Pa) is a human pathogen causing life-threatening infections in immunocompromised and wounded people worldwide. Pa's infections are particularly deadly when occurring in the lungs of patients suffering from cystic fibrosis (CF). These infections become chronic and are very difficult to treat due to Pa’s resistance to multiple antibiotics. To successfully colonize a host and develop infection, Pa produces an arsenal of virulence factors. One such factor is pyoverdine, a high-affinity siderophore that provides Pa with iron, essential for the survival and scarce in the human lung environment. Our group showed that pyoverdine production is regulated by elevated calcium (Ca²⁺), and this regulation requires an earlier identified Ca²⁺ sensor, EF-hand protein (EfhP). This study seeks to characterize EfhP regulation of Pa’s response to Ca²⁺, particularly pertaining to critical iron uptake pathways. We have established that efhP deletion significantly hinders Ca²⁺-dependent induction of Pa pyoverdine production in the lab strain PAO1. By using PCR and efhP-specific primers, we confirmed the presence of efhP in five CF clinical isolates. We observed that these clinical isolates express efhP at levels at least two-fold greater than that in PAO1. The isolates also showed increased pyoverdine production at 5 mM Ca²⁺ vs. the no Ca²⁺ condition. These data suggest that EfhP plays a similar role in mediating Ca²⁺ regulation of pyoverdine production in CF isolates. Current research aims to characterize the role of EfhP functional domains in regulating pyoverdine production by testing a series of strains expressing mutated EfhP. New knowledge gained will support further studies to ultimately develop novel efficient medications to improve the quality of life of CF patients who struggle with chronic P. aeruginosa infections.   

 

G-24     Adriahna Blackburn

Research Collaborators:  Christopher Hamm, Jesna Merin Varghese, Matthew Cabeen

Research Presentation Title:  A paradoxical role for the PrtR repressor in non-canonical pyocin expression seen in Pseudomonas aeruginosa

Faculty Research Mentor:  Matthew Cabeen, Microbiology and Molecular Genetics

 

Pyocins are intraspecies killing particles that resemble bacteriophage tails and are normally produced by Pseudomonas aeruginosa cells in response to DNA damage. The expression of pyocins in wild-type P. aeruginosa is controlled by the transcriptional activator PrtN, which is normally repressed by PrtR. DNA damage, detected by RecA, triggers pyocin production through RecA-mediated cleavage of PrtR. Pyocin-producing cells then display high levels of pyocin gene expression, culminating in explosive cell lysis to release the phage-sized pyocin particles. We recently discovered that in cells lacking the tyrosine recombinase-encoding xerC gene, pyocin production occurs independently of induced DNA damage and of RecA, implying that PrtR cleavage is not necessary for pyocin gene expression in this background. However, blocking PrtR cleavage by mutating it to an uncleavable PrtR_S162A version completely inhibits functional pyocin production in ∆xerC cells. While ∆xerC prtRS162A cells do not produce functional pyocins, they still do activate a pyocin transcriptional reporter and lyse, albeit with altered kinetics and cell morphology. Thus, the impediments to pyocin production in these cells remain mysterious. We conducted comparative transcriptomic and proteomic analyses in attempt to identify differences that might elucidate why ∆xerC prtR_S162A cells cannot generate functional pyocins. Although various expression disparities were observed, we identified no obvious candidates explaining the difference, and moreover found that complementing the 10 most downregulated genes did not restore functional pyocin production. We hypothesize that pyocin production may be very sensitie to the stoichiometry of the constituent components.  

 

G-25     Amber Dohmen

Research Collaborators:  Saylor Hampton, Catalina Bradley, Gunnar Hoogerwerf, Clarice Huffman, Scout Powell, Sarah Teeman, Rosalie Dohmen, Wouter Hoff

Research Presentation Title:  Identifying the physiological function and signaling pathway of novel bacterial photoreceptors

Faculty Research Mentor:  Wouter Hoff, Microbiology and Molecular Genetics

 

Biological light detection by photoreceptor proteins in the eyes of animals is well known. More recently, it has become clear that approximately one-quarter of all bacteria contain photosensitive proteins. The biological functions triggered by these proteins are mostly unknown. Photoactive yellow protein (PYP) is a bacterial photoreceptor that enables blue-light sensing by binding a unique p-coumaric acid (pCA) chromophore. PYP was first identified in the bacterium Halorhodspira halophila, where it triggers a negative phototaxis motility response. This is the classical response triggered by photoreceptors in phototrophic bacteria. PYP is also known to photo-regulate photoprotective pigment formation in the bacterium Rhodospirillum centenum and biofilm production in the bacterium Idiomarnia ioihiensis. Genome studies suggest a more widespread genetic link between photoreceptor genes and genes encoding proteins regulating biofilm formation. The goals are to address two gaps of knowledge: to use bioinformatics-based predictions and experimental approaches to (1) uncover the biological function for some of the remaining approximately 1,000 additional clear homologs of PYP encoded in bacterial genomes in DNA sequence databases the biological function is unknown; and (2) to gain insights into the components of the signal transduction chain that PYP uses to transduces its signal to initiate a physiological response. Based on previous bioinformatics analysis of their genome sequences, three different bacterial species will be investigated: Massilia albidiflava, Massilia plicata, and Nitrincola alkalilacustris. PCR experiments for M. ablbidlava and M. plicata confirmed the presence of pyp homologs in the genomes of these organisms. The hypothesis is that in the first two organisms, PYP sends its signal to a protein containing a GGDEF motif to regulate the formation of biofilm in response to blue light. Biofilm assays were used to test this hypothesis. For the third organism, we hypothesize that a PYP homolog relays its signal to an associated MCP domain, which then initiates a phototactic response to blue light. Results from phototaxis assays indicated that the higher the percentage of agar the more the bacteria swim on the surface and the lower the degree of motility of N. alkaliliacustris.

 

G-26     William Ertl

Research Collaborators:  Swarnali Mukherjee

Research Presentation Title:  Elucidating Proton Pumping in Cyanobacteria Complex I Using Site-Directed Mutagenesis and Phenotypic Analysis

Faculty Research Mentor:  Robert Burnap, Microbiology and Molecular Genetics

 

Complex I is a protein complex classically found in the mitochondrial membrane of eukaryotes and is essential for generating ATP through oxidative phosphorylation and water by oxygen reduction. In bacteria such as cyanobacteria, the protein complex, known as the NDH-1 complex, is a part of the thylakoid membrane and drives the proton gradient to the lumen of the thylakoid membrane. This occurs through electron transfer from a ferredoxin (Fd) to a peripheral arm region where, through sequential reactions with iron-sulfur clusters, a plastoquinone is reduced to plastoquinol. This reduction process provides the energy to drive proton pumping by the membrane-spanning subunits of the complex. However, this coupling mechanism between electron transfer and proton pumping remains to be understood. Evidence has shown through using site-directed mutagenesis that conserved amino acid residues in transmembrane region subunits, in our case NdhF4 and NdhD4, are critical intermediates in proton transfer within the complex, protein pumping to the thylakoid lumen, and maintaining optimal cyclic electron flow (CEF). Additionally, the NdhO subunit in the peripheral arm region has become characterized as an inhibitor of cyclic electron flow by maintaining a strong affinity for ferredoxin after it has been oxidized through electron transfer. Our goal has been to further characterize these regions through mutagenesis studies and spectroscopic assays in order to gain a better understanding of the importance each one contributes to the coupling between electron flow and proton pumping. Notably, there has been insufficient evidence to support whether proton pumping is truly coupled with the exchange process of PQH₂ and PQ in a proton-coupled electron transport mechanism. Future studies with the NdhB subunit, another transmembrane subunit that pumps protons, will help further characterize the mechanism this protein complex catalyzes and its importance in generating ATP and water. In conclusion, the NDH-1 complex is a highly intriguing protein complex that catalyzes a sophisticated reaction, and its study has real-world applications in mechanistic understanding and building a foundation for treating mitochondrial disease (Parkison’s, MS, etc.) that affects hundreds of thousands of people worldwide.

 

G-27     Ashley Jackson

Research Collaborators:  Autumn Hansen, Matthew Cabeen

Research Presentation Title:  Relative roles of holin and lysin enzymes in cell lysis and pyocin release by Pseudomonas aeruginosa

Faculty Research Mentor:  Matthew Cabeen, Microbiology and Molecular Genetics

 

Pseudomonas aeruginosa (P. aeruginosa) is a rod-shaped, Gram-negative, human opportunistic pathogen that responds to DNA damage by producing toxic intraspecies-killing protein complexes known as pyocins. Included in the pyocin gene cluster are cell lysis genes that encode a holin (hol) and a lysin (lys). The holin makes pores in the inner membrane of the cell while the lysin streams through the pores to cleave the peptidoglycan layer cell wall, causing explosive cell lysis and allowing pyocin release. Elsewhere in the genome is the alp gene cluster, alpB-E, which contains another holin-encoding gene, alpB.  When P. aeruginosa detects DNA damage, the cell responds by initiating the so-called SOS response, during which the RecA protein is activated. RecA stimulates the cleavage of a repressor, PrtR, thus allowing the production of PrtN, an activator of the pyocin gene cluster. Our lab discovered an alternative, RecA-independent pathway for pyocin production that still depends on PrtN and causes holin- and lysin-mediated cell lysis. We studied the relative roles of known holins and lysins in the lytic process during pyocin production. We have observed that in strains where only lys is deleted, shrinking lysis is observed rather than explosive lysis. Conversely, when hol is deleted, we observe explosive cell lysis, linking the lysin to explosive lysis. When both hol and lys are deleted, few cells exhibit shrinking lysis, suggesting that another holin is active. When alpB is deleted, fewer cells lyse, but they still show explosive lysis, implying that lysin is still degrading the peptidoglycan layer. P. aeruginosa encodes one other known holin from the cidAB locus. To better understand how cidAB contributes to P. aeruginosa cell lysis during pyocin production, we are creating strains with all combinations of hol, alpB, cidAB, and lys deletions, examining their mode of lysis by timelapse microscopy and assessing pyocin release with a pyocin killing assay.  

 

G-28     Ty Young

Research Collaborators:  Carrie Pratt, Mostafa Elshahed

Research Presentation Title:  Exploring AGF Communities in Avian Host

Faculty Research Mentor:  Noha Youssef, Microbiology and Molecular Genetics

 

Anaerobic gut fungi (AGF, phylum Neocallimastigomycota) reside in the digestive tract of herbivorous hosts. AGF aid in the breakdown of complex polysaccharides into products usable by their host. To date, AGF have only been cultured from mammals and non-avian reptiles. However, ostriches fit many of the criteria to host AGF. Due to this, ostriches have been a potential candidate in classifying AGF diversity. Ostriches are one of the only avian reptiles that are truly herbivorous. They also possess a long digestive track, an enlarged portion of their digestive tract, and an extended digestion time. All these factors are vital to the growth of AGF and allowing them to establish communities in hosts.

 

G-29     Bailee Arthur

Research Collaborators:  Sanmi Alake, Femi Olawale, Jessica Orphan, Bryant Keirns, Sam Emerson, Brenda Smith, Edralin Lucas, Ashlea Braun

Research Presentation Title:  Fecal Short Chain Fatty Acids Predict Eating Behavior of Postmenopausal Women after Completion of a Dietary Pulses Intervention

Faculty Research Mentor:  Edralin Lucas, Nutritional Sciences

 

Objectives: Dietary fiber has health benefits mediated in part by gut-derived short chain fatty acids (SCFAs), and interventions focused on supplemental sources (e.g., pulses) may have sustained health effects. The objective of this study was to determine if fecal SCFAs after 9 months (9 m) of pulse supplementation predict eating behavior of postmenopausal women. Methods: Postmenopausal (≥1 year without menstruation) women (n=23), aged 45-70 years, not on hormone replacement therapy or medications that affect gut health, not smoking or using excessive alcohol, participated. All were asked to consume 100 g of pulses (~½ cup, alternating between chickpeas, kidney beans, pinto beans, black-eyed peas, & lentils) daily for 9 m, and to maintain their normal diet and lifestyle. Six months after stopping supplementation, all completed 3-day food records and the 3-factor eating questionnaire (TFEQ) to assess cognitive restraint (CR), uncontrolled eating (UE), and emotional eating (EE). Linear regression was used to examine predictors of TFEQ measures, and Spearman correlations to examine relationships between TFEQ measures and SCFAs. Results: Six months after supplementation, women had a mean intake of 20.2 g dietary fiber/day (+/- 8.6). For each standard deviation (SD) increase in acetic acid during supplementation, CR decreased by -0.31 SD while UE increased 0.33 SD. When adding baseline levels to the model, β for CR increased to -0.26 and decreased to 0.04 for UE. Further, baseline levels predicted UE (P=0.04), suggesting persistent baseline effects. Spearman correlations indicate acetic acid (ρ=-0.57, P=0.01) and n-butyric acid (ρ=-0.46, P=0.04) were negatively correlated with CR, while baseline levels of propionic acid were negatively correlated with CR (ρ=-0.43, P=0.02) and baseline acetic acid was negatively correlated with EE (ρ=-0.51, P=0.01). The correlation between baseline acetic acid and UE was moderate (ρ=-0.36, P=0.07). Conclusion: Pulse consumption by postmenopausal women contributes to dietary fiber intake above the national average. Certain eating behaviors (e.g., UE) may warrant longer intervention periods or additional behavioral assistance to sustain positive impacts.

 

G-30     Nishi Gandhi

Research Collaborators:  Allison Hepworth

Research Presentation Title:  Nutritional Aspects of Recipes on Pinterest for Increasing Breast Milk Production

Faculty Research Mentor:  Allison Hepworth, Nutritional Sciences

 

Background: Breastfeeding builds a special bond between an infant and their mother. Breast milk is also the ideal source of nutrition for infants. Many mothers in the United States want to breastfeed, but often feel discouraged and lack support. Mothers are willing to try different foods and techniques to meet their breastfeeding goals. Pinterest is a popular source of recipes, used by around 50% of women. Identifying popular recipes promoted for increasing lactation can inform the design of research studies that test galactagogues' effectiveness. It can also be used to counsel mothers in healthcare settings. Methods: This study will be a content analysis of the most pinned Pinterest recipes that promote lactation between May 1, 2023, and November 30, 2023. The top 5% of pins that included a link to a specific recipe were entered into the nutrient analysis software ESHA Food Processor. These recipes were pinned between 75-1,783 times. We calculated the frequency of all individual ingredients, the choline and iodine content per serving, and the percentage of calories from carbohydrates, proteins, and fats. Results: Preliminary results are based on an analysis of 40 out of 53 recipes. The most common lactation boosting ingredients were oats, brewer’s yeast, flaxseeds, coconut milk, and almond milk. The median amount of choline was 14 mg per serving (range: 0-175 mg). The median amount of iodine was 5 mcg per serving (range: 0-42 mcg). The median percentage of calories from carbohydrates was 50% (range: 1.2% to 99%). The median percentage of calories from protein was 7% (range: 0% to 59%). The median percentage of calories from fat was 40% (range: 0.7% to 53%). Conclusion: Mothers are actively seeking ideas on Pinterest for how to increase their milk supply through food/drink recipes. The top recipes included ingredients that are thought to increase milk supply and require additional evidence to support these claims. There are opportunities to enhance the nutrient composition of popular Pinterest recipes to better align with the recommended daily goals for lactating mothers.

 

G-31     Aiden Yejoon Kim

Research Collaborators:  R. Sigdel, P. Johnson, G. Meade, S. Emerson, W. Chowanadisai

Research Presentation Title:  Using customized polygenic risk scores to improve the study of nutrient metabolism gene effects in nutrient-gene association models

Faculty Research Mentor:  Winyoo Chowanadisai, Nutritional Sciences

 

Objective: This study aims to enhance the precision of association studies by distinguishing the effects of individual nutrient metabolism genes from the broader genetic background on various health measures. Methods: The approach involves generating polygenic risk scores (PRS) from genome-wide association study (GWAS) summary statistics to be utilized in regression models to assess nutrient-gene associations with health. The health impact of a single gene of interest is often embedded within pre-existing, genome-wide PRS, making separation challenging; to address this hurdle, we created a customized PRS and excluded the genetic region of the gene of interest. We tested this approach on metal transporter gene SLC39A8 and single nucleotide polymorphism (SNP) rs13107325 due to its known associations with increased body mass index (BMI) and reduced circulating high-density lipoprotein (HDL). We used the UK Biobank population cohort (Caucasian only, no kinship) and PRSice-2 software to compute individual PRS as an additional (experimental) covariate. Quantile (median) regressions included rs13107325 genotype (encoded as 0, 1, or 2 under an additive model) as the primary exposure, BMI or HDL as the primary outcome, and the experimental PRS for BMI or HDL (omitting a ±1 million base pair region around SLC39A8), dietary manganese intake, age, sex, deprivation index (as a measure of socioeconomic status), education (qualifications), and household income as covariates. Control regressions lack the experimental PRS as a variable.  Results: The results revealed that inclusion of the experimental PRS increased statistical significance and narrowed variability for BMI (p-value=5.97E-10 to 4.46E-12, beta=0.249±0.0402 to 0.274±0.0395, N=107,966) and HDL (p-value=2.99E-16 to 1.08E-16, beta=-0.0307±0.00375 to -0.0285±0.00343, N=95,318).

Conclusions: This tailored PRS demonstrates improved statistical power in regression models, thereby better elucidating the influence of single nutrient metabolism genes and their respective SNPs on health measures. This methodology can be universally applied to any target nutrient metabolism gene and enhance the robustness of genetic associations.

 

G-32     Kaitlin Koons

Research Collaborators:  Allison Hepworth

Research Presentation Title:  Associations Between Food Parenting and Child Eating Behavior: A Survey of Anti-Diet Parents

Faculty Research Mentor:  Allison Hepworth, Nutritional Sciences

 

Background: Parents can impact their children’s eating behaviors and body perceptions through their food parenting practices, including family meals and comments about nutrition and body size. The Division of Responsibility in Feeding is one approach to food parenting in which parents determine what, when, and where to feed their child. Children decide whether and how much to eat of the foods offered. The Division of Responsibility in Feeding is thought to create a positive household food environment. This study's purpose is to test associations among parents' use of the Division of Responsibility in Feeding, their children's enjoyment of food, and child food acceptance. The sample will consist of parents who identify as anti-diet parents. The “anti-diet” movement was developed in response to the negative effects that “diet culture” has had on eating behavior in the United States. I hypothesize that children of parents who use the Division of Responsibility in Feeding will have greater enjoyment of food and greater food acceptance.  Methods: A minimum sample of 272 parents will be recruited from Facebook, Instagram, and an email listserv. All recruitment platforms target parents who are interested in anti-diet parenting. The Division of Responsibility in Feeding will be measured using a validated 12-item survey, the sDOR.2-6y (Lohse & Mitchell, 2021). Children’s enjoyment of food (4 items) and food acceptance (i.e. food fussiness; 7 items) will be measured using the subscales from the validated Child Eating Behavior Questionnaire (Carnell & Wardle, 2007). We will conduct Pearson correlations to test our hypotheses. Results: This study received IRB approval on February 16th, 2024 (IRB-24-61). Data collection will be completed in March 2024. Results will be finalized prior to the Undergraduate Research Symposium. Conclusion: The Division of Responsibility in Feeding is recommended by clinicians to support positive eating behaviors in children. Our study results are expected to fill a current gap in knowledge surrounding the use of the Division of Responsibility in Feeding in the anti-diet movement and its associations with children’s eating behavior. 

 

G-33     Madi Myers

Research Collaborators:  Taylor Allen, Harriet Okronipa

Research Presentation Title:  Hunger in higher education: A focus on food insecurity among international students at the Oklahoma State University

Faculty Research Mentor:  Harriet Okronipa, Nutritional Sciences

 

Background/objectives: Students in higher learning institutions are a vulnerable population in the United States to food insecurity, with levels of food insecurity much higher than the national average. International students face a massive change when moving to the U.S. and may be vulnerable to food insecurity and its impacts. However, there is limited data examining food insecurity among this population. Our study sought to examine the prevalence of food insecurity among international students at Oklahoma State University and to understand the coping strategies employed when faced with limited food access or resources.  Methods: The study was a cross-sectional design and was conducted through an online survey of international students on the Oklahoma State University campus about their experiences with food access. Data was collected through a Qualtrics survey sent out by email. There were 193 participants. The USDA Six-item Short Form Food Security Survey analyzed food security level data. Coping strategies were analyzed using a questionnaire 

Results:  On average, participants were 28±5.3 years old, mostly male (55.6%), graduate students (91.7%), single (68.1%), worked part-time (63.3%), and not receiving any financial aid (65.4%) We found that 43.64% of participants had some level of food insecurity. Of the 40.18% who experienced food insecurity, 29.70% had low food security, and 13.94% had very low food insecurity. Most international college students employed some type of strategy to cope with limited food access including getting help from family or friends (58.39%), cutting down on the size of their meals (73.58%), skipping meals (59.24%), stretching meals (63.23%), eating community meals provided by local community groups (35.85%), purchasing cheap, processed foods (65.84%), sacrificing spending money in another area (47.77%), and selling or pawning items (14.01%). Conclusion: There is a large percentage of international students who struggle with food insecurity. This is a growing issue that needs to be addressed. Future research should examine the factors associated with food insecurity among this population so as to inform future interventions.  

 

G-34     Angelique Robinson

Research Collaborators:  Jong Beom Jin

Research Presentation Title:  The Role of Glucose Metabolism in Postnatal Heart Regeneration After Myocardial Infarction

Faculty Research Mentor:  Jiyoung Bae, Nutritional Sciences

 

Heart disease is the leading cause of death and illness in the United States, with Oklahoma ranking among the states with the highest mortality rates. One major challenge is the adult heart's inability to regenerate tissue after injuries like a heart attack. It has previously been demonstrated that neonatal mice have the ability to regenerate their hearts after injury, a capability that is lost seven days after birth. This loss coincides with a critical shift in cardiomyocyte energy metabolism during the transition from neonatal to adult stages. O-GlcNAcylation (O‐GlcNAc), a common modification on nuclear and cytoplasmic proteins, is crucial for regulating glucose metabolism and increases with elevated glucose uptake. O-GlcNAc levels, regulated by the enzymes O-GlcNAc transferase (OGT) and O-GlcNAcase (OGA), are essential for cellular functions, including signal transduction, transcription, and translation. Inhibiting OGA enhances O-GlcNAcylation levels. However, the effects of OGA inhibition on heart failure and regeneration in mouse models have not been fully studied. Thus, we hypothesize that OGA inhibition by NButGT injection will promote cardiomyocyte proliferation and heart regeneration. To investigate the role of OGA inhibition in heart regeneration, we utilized neonatal mice at postnatal day 7 (P7) for myocardial infarction (MI) surgery. The mice were treated with the OGA inhibitor NButGT for ten days before and after the MI injury. We performed various analyses, including immunohistochemistry to measure cardiomyocyte proliferation and trichrome staining to evaluate heart regeneration. Our results show that inhibiting OGA by NButGT injection after MI promotes cardiomyocyte proliferation, as indicated by the mitosis marker phospho-histone 3 (pH3) staining. Remarkably, NButGT injection to the neonatal mouse heart for ten days before and after MI injury reduces scar formation and promotes heart regeneration, as revealed by trichrome staining. OGA inhibition by NButGT promotes postnatal cardiomyocyte proliferation and heart regeneration. These findings suggest a promising new therapeutic strategy for treating human heart failure. 

 

G-35     Ty Shreve

Research Presentation Title:  IronGate(R) herbicide efficacy against Bromus spp. grass weeds in Oklahoma wheat cropping systems

Faculty Research Mentor:  Liberty Galvin, Plant and Soil Sciences

 

Bromus spp. is a particularly problematic weed in Oklahoma due to its competition with wheat and other small grain crops. This experiment aimed to study the efficacy of IronGate® against other herbicides currently available for controlling Bromus spp. This study occurred at the Agronomy Research Station in Stillwater, OK. Showdown wheat variety was planted in late September in a field previously infested with Bromus techtorum and Bromus secalinus. There were six different treatments with one control per block, with four replications. The herbicides used in the trials were IronGate®, PowerFlex® HL, and Axial® Bold.  IronGate® showed an average of 54.25% control while, Axial Bold® showed 52.5% control, and PowerFlex HL® showed an average of 41% control of Bromus spp. Previous research from Oklahoma State University identified Bromus Secalinus as resistant to group 2 herbicides². PowerFlex HL® is a group 2 herbicide which suppressed Bromus spp. less than 50% of the time. With herbicide resistance being an issue in Oklahoma and across the country, herbicides with different formulations, such as IronGate® show promise for diversifying chemical weed control management in wheat and small grain cropping systems.

 

G-36     Withdrawn

 

G-37     Luke Reynolds

Research Collaborators:  Bárbara dos Santos, Alexandre Rocateli

Research Presentation Title:  Evaluating the Effects of Interseeding Winter Wheat on Bermudagrass Summer Early Production

Faculty Research Mentor:  Alexandre Rocateli, Plant and Soil Sciences

 

In Oklahoma, interseeding winter wheat (Triticum aestivum L.) on dormant bermudagrass [Cynodon dactylon (L.) Pers.] pastures could increase pasture’s forage yield and quality from late fall to mid-spring. Thus, the objective of this study was to compare the forage yield and nutritive value of three different forage production systems: (i) in-season bermudagrass (BER), (ii) stockpiled bermudagrass (BER+STOCK), and (iii) interseeded winter wheat into bermudagrass (BER+WHEAT) in six different established bermudagrass cultivars from late fall 2022 to early summer 2023. The experimental design consisted of a 6×3×4 factorial arranged as a split-plot design. The six cultivars were the main plots; the three systems were the subplots four times replicated. For data collection, three biomass samples of 0.5 m² were taken from each subplot at their assigned harvests of bermudagrass and wheat at first cuts only. The samples were dried at 55° C until a constant weight was achieved, then weighed to determine aboveground dry matter. Samples were ground using a Wiley mill with a 1 mm sieve. NIRS analysis was performed to estimate forage nutritive quality indicators. Results indicated that BER+STOCK had the greatest forage yield among the three systems but had lesser nutritive value. BER+WHEAT had a slightly smaller production than the BER, but it had the greatest nutritive among all systems. Future seasons must be fully analyzed to validate our findings.

 

G-38     Addison Darby

Research Collaborators:  Shelby McMahan

Research Presentation Title:  Influence of Micro Consumer Interactions on Grassland Diversity

Faculty Research Mentor:  Benedicte Bachelot, Plant Biology, Ecology, and Evolution

 

Micro consumers such as invertebrate herbivores and fungal pathogens influence the diversity, composition, and productivity of plant communities. Jointly, these consumers may cause additive effects if they target the same plant species or compensatory effects if they target separate species. Characterizing how these biotic pressures interact with one another across environmental gradients is important in understanding how individual ecosystems may shift in response to climate change and other disturbances. As part of a global study with participating locations across six continents, we established factorial exclusion treatments for insects, mollusks, and fungi at the McPherson Preserve. Treatments to reduce both foliar fungi and arbuscular mycorrhizal fungi were applied separately. We hypothesize that antifungal treatments targeting AMF in combination with no molluscicide will result in the largest decrease in the ratio of forbs to grasses. Inversely, we hypothesize that the highest proportion of forbs to grasses would be present in plots treated with insecticide, molluscicide and no foliar or AMF fungicide.  To test these hypotheses, we set up three replicated blocks with eight 5 x 5m experimental plots each. Broad spectrum insecticide, fungicide, and molluscicide were applied randomly throughout the eight plots in each of the three blocks. We collected community composition data once a year for two years by estimating the percent coverage of the species present. Using a One-Way ANOVA test to compare the ratio of forbs and grasses between treatments, we found a p-value of 0.440248. Given the p-value is > a=0.05, we are unable to reject the null hypothesis. It is important to take into consideration that we have only conducted two years of the four planned for this project, and it might not be until the final year that significant differences between the treatments become apparent. These experiments across diverse ecosystems are important in informing our understanding of how invertebrate herbivores, fungal pathogens, and fungal symbionts interact with one another and impact plant communities across the globe.  

 

G-39     Gemini Hoffman

Research Collaborators:  Jacob Martin, Mercy Dahunsi, Adam Nemeth, William Cook, Eduardo Colmenares, Charles Cannon, Antonio Castilla

Research Presentation Title: Kinship Connections: Investigating fine scale genetic structure in a highly fragmented population of gray oak.

Faculty Research Mentor:  Antonio Castilla, Plant Biology, Ecology, and Evolution

 

Plants are unable to move by themselves and how individuals in specific habitats are distributed can have a significant impact on processes like pollen and seed dispersal, which shapes the genetic variation within populations. Gray oak, Quercus grisea, normally occupies humid canyons in arid regions of the southwestern United States as well as northern Mexico. This results in the clustered distribution of trees within populations. Prior research has examined the genetic variation of gray oak in relation to its hybridization with species in its genus, but none have explored genetic variation and how it relates to spatial distribution in a population. To test for the existence of FSGS in Quercus grisea, we collected leaf samples from 75 gray oak individuals and their DNA was extracted. Using RAD sequencing, a panel of 2,533 SNPs was created. Both a principal component analysis and Neighbor-Joining tree were conducted to examine the clustering of individuals in relation to their genetic distance. In addition, spatial auto-correlation tests are currently being performed to study the existence of FSGS and its spatial extent. Preliminary results indicate a significant FSGS within the studied population, where the kinship between individuals up to 100 meters is increased. This provides a further understanding of how factors, such as geographic distance, influence genetic connectivity within tree populations. To manage and conserve species genetic resources, ex situ conservation efforts should be made using kinship as a basis in their management, prioritizing the collection of seeds from areas where there is lower genetic relatedness.   

 

G-40     Shelby McMahan

Research Collaborators:  Elizabeth Struble, Kianoosh Hassani, Ny Aina Rakotoarivony, Hamed Gholizadeh, Bene Bachelot

Research Presentation Title:  Remote Sensing Fails to Detect How Lespedeza Cuneata Invasion Alters Soil Bacteria Communities

Faculty Research Mentor:  Benedicte Bachelot, Plant Biology, Ecology, and Evolution

 

Species invasion is a prime example of a “good thing gone bad.” Lespedeza cuneata “sericea,” originally introduced in the United States as a forage plant, quickly became a conqueror of vast areas in the grasslands from Mexico to Canada. With its persistence in less-than-ideal conditions, competitiveness against the native species, and swift reproduction, its detrimental effects stretch from aboveground to belowground by decreasing plant diversity and increasing homogenization of plant and fungal composition. Previous studies have separately examined these negative impacts on a small scale, impeding our abilities to scale up across heterogeneous ecosystems, such as tallgrass prairies. In this study, we examine large scale effects, utilizing community ecology approaches and remote sensing. We hypothesize that 1) sericea invasion will encourage a drastic shift in the microbiome soil communities and 2) hyperspectral imagery will be able to detect these belowground changes. To test these hypotheses, we collected plant cover data and soil samples across 99 plots at the Joseph H. William Tallgrass Prairie Preserve (OK). From these soil samples, we used phospholipid fatty acid markers to characterize the bacterial and fungal communities. Additionally, we collected hyperspectral imagery for these plots. Using redundancy analyses and linear regression, we investigated how sericea invasion influences microbial communities. Confirming our first hypothesis, we found sericea invasion drastically shifted the microbiome; additionally, we found a stronger effect on the bacterial community than the fungal one. Sericea abundance was positively correlated with gram-negative, eukaryote, and actinomycetes. These three groups of bacteria are associated with high availability of plant-derived carbon and high decomposition rates, suggesting that sericea abundance might enhance soil fertility. Using a Mantel test, we also tested for a correlation between hyperspectral data and the microbial communities; we found the hyperspectral data was not able to capture changes in these communities, contrary to our second hypothesis. In lieu of this, an advisable next step would be to collect more detailed microbial community data, since our approach resulted in a coarse description of the microbiome, so that we can continue looking for a way to utilize remote sensing to study biological invasion across large scale. 

 

G-41     Cade Seabolt

Research Collaborators:  Cindy Newlander

Research Presentation Title:  Early growth and germination in two hybridizing oak species

Faculty Research Mentor:  Antonio R. Castilla, Plant Biology, Ecology, and Evolution

 

Harvard oak (Quercus havardii) is a low-growing deciduous shrub adapted to arid habitats with sandy soils in the western U.S. The species has a characteristic distribution range with two disjunct groups of populations that are genetically and morphologically distinct. Previous research suggests that western populations constitute a distinct species named Q. welshii, which has experienced substantial hybridization with two congeneric oak species (Q. turbinella and Q. gambelli). Our study examines the potential convergence between Q. turbinella and Q. welshii regarding their germination and early seedling growth. 175 acorns were collected from two populations of Q. welshii and 24 acorns from one population of Q. turbinella. We measured acorn length and conducted a germination experiment in a greenhouse environment with constant light and temperature conditions. We are currently monitoring seedling emergence and growth. Our results showed that acorns of Q. welshii are larger than those of Q. turbinella. The average timing for seedling emergence was similar for both species. Interestingly, we found different relationships between acorn size and seedling emergence for our study species. Larger acorns germinated faster than smaller ones for Q. welshii, whereas the opposite trend was detected for Q. turbinella. Our results revealed that despite a potential history of hybridization between Q. welshii and Q. turbinella, these species still maintain different germination and early seedling growth strategies.  

 

G-42     Elizabeth Struble

Research Collaborators:  Gina Errico, Shelby McMahan, Addison Darby, Benedicte Bachelot

Research Presentation Title:  Spilling the Beans: The Effect of Coffee Spillover on Arbuscular Mycorrhizal Fungi

Faculty Research Mentor:  Benedicte Bachelot, Plant Biology, Ecology, and Evolution

 

Tropical forests are the most biologically diverse biome and provide services in regulating the global climate and water supply. Despite their importance, humans threaten tropical forests through activities like agricultural production. Agriculture, such as coffee plantations, disrupts tropical areas through fragmentation and creates edges, which alters ecological processes. These plantations are often established next to forests, opening the door for fungi at high densities to spillover to adjacent forests. Coffee plantations are managed along two approaches: shade and sun. In shade systems, chemical inputs are minimal, and the natural canopy is maintained. In sun systems, the canopy is removed, and large chemical inputs are used. This difference leads to shade systems having high productivity and biodiversity. The management of coffee plantations might lead to strong or weak potential for fungal spillover, such as arbuscular mycorrhizal fungi (AMF). AMF are vital parts of plant-microbial interactions because they assist plants with up-taking nutrients in exchange for carbon. I hypothesize: (1) the AMF community will be less diverse closer to the edge because of vegetation alterations and (2) the AMF community near shade management will be more diverse because of the varied associations with plants that can spill over. To research this, we studied coffee plantations (2 shade and 2 sun) in Costa Rica. Seedlings were assigned fungicide or water treatment. Soil samples were collected from each plot, and DNA was extracted using a Qiagen PowerSoil Pro Kit. DNA samples were sequenced using Illumina sequencing and fungal-specific primers. From this, operational taxonomic units (OTUs) were identified, which can be used to match OTUs with AMF species. We found distance had a marginal effect on AMF composition, supporting the first hypothesis, but management didn’t have an effect unlike what was hypothesized. This could be because the forest location overwhelmed the effects of other variables on AMF composition. This research indicates coffee plantations affect the AMF community of nearby forests. As tropical forests are vital to regulating climate and host great biodiversity, understanding how they are affected by an economically important crop like coffee is key to lessening the effect of edge effects and fragmentation.