Life Sciences Commons^™

Patterns And Sources Of Variation In Heterospecific Pollen Deposition In Flowers Of The Native Blue Cardinal Flower (Lobelia Siphilitica), Allie Drinnon

Undergraduate Honors Theses

Plants species interactions via pollinators are a model system to understand the mechanisms that generate plant diversity in nature. However, most studies have focused on plant-plant interactions via pollinator attraction while ignoring the role of plant-plant interactions via pollen transfer. Heterospecific pollen transfer (henceforth HP) can be common and have negative fitness effects. Negative HP fitness effects may prompt the evolution of adaptive strategies to minimize them. However, the extent of spatial variation in HP load size within and among populations, a tenet for natural selection, remains unexplored. Such knowledge would hence constitute a first step in advancing our understanding …

Epidemiology And Impacts Of A Leaf Spot Disease In Veratrum Viride (Melanthiaceae), Leeah R. Sutton, Foster Levy

Undergraduate Honors Theses

Fungal phytopathogens can cause disease epidemics in crops, weeds, and
populations of native plants. To investigate the impact of a foliar phytopathogen on the native herbaceous species, Veratrum viride, a demographic and disease assessment was carried out on two high elevation grassy bald populations on Roan Mountain, Tennessee. A leaf spot disease impacted all plants in both populations, causing widespread premature senescence of leaves and stems. Disease severity increased over the course of the growing season. Based on host disease symptoms and fungal conidia morphology, Pseudocercosporella sublineolata was shown to be the causal pathogen. A study of herbarium specimens …

Investigating The Effect Of Longhorned Milkweed Beetle Larval Root Feeding On Resprouting In Common Milkweed, Margaret Donnan

Undergraduate Honors Theses

Clonal reproduction is an important form of reproduction for many plants, and plants can grow clonally through a variety of methods, such as belowground stems, specialized organs, or adventitious buds on their roots (Herben and Klimešová 2020). In plants that reproduce via buds on their roots, researchers have shown that damage to roots can stimulate bud production and sprouting (Bartušková and Klimešová 2010). Common milkweed (Asclepias syriaca) is a root- sprouting perennial plant that receives yearly damage to its roots via the feeding of the larvae of the specialist longhorned milkweed beetle (Tetraopes tetrophthalmus) (Erwin et al. 2013). In this …

Climate Change And Conservation Of Milkweed: Evidence Of Extensive Admixture Between Common Milkweed And Poke Milkweed, Elizabeth Davies

Undergraduate Honors Theses

Global climate change can drive many changes in species interactions. One primary way it affects species is by changing climates, causing species to expand their ranges and allowing them to interact with species from whom they were previously isolated. In plants, new species interactions can result in hybridization – the creation of hybrid offspring between two separate species. This hybridization can increase gene flow between the species and lead to introgression, the transfer of genetic material from one species to another through hybrid backcrossing with the parent species. My thesis investigates hybridization in the model system Asclepias (milkweed) by analyzing …

Using A Machine Learning Model To Predict Plant Inflorescences Based Upon Its Soil Microbiome, Luke Denoncourt

Undergraduate Honors Theses

The UN estimates that the global population could reach 9.7 billion by 2050 (United Nations). As a result, the amount of food required to feed humanity is thought to double by 2050 (Ray et al., 2012). Humanity must find a way to increase crop production without increasing fertilizer usage and eutrophication, which can be done using the soil microbiome. Using potted plants with soils inoculated with Pseudomonas alcaligenes, Pseudomonas denitrificans, Bacillus polymyxa, and Mycobacterium phlei, both the shoot and root growth of pea and cotton plants was significantly increased (Egamberdieva & Höflich, 2004). In this study, utilizing a random forest …

Three Centuries Of Vegetation Change In The William & Mary College Woods Reconstructed Using Phytoliths, Timothy Terlizzi

Undergraduate Honors Theses

The College Woods, west of William & Mary’s campus, consists of ~900 acres of protected southern mixed hardwood forest. The woods surround Lake Matoaka, a former millpond established in ~1700. Despite the rich history of the area, little is known about how the dominant vegetative landcover has shifted over the last 300 years. This study set out to quantify the modern vegetation within the College Woods via the phytolith assemblages within the soil and identify shifts in the assemblages since the creation of Lake Matoaka and whether these changes are distinct from the vegetation that existed in the area before …

Characterizing The Microbiome Of Floral Nectar Of Asclepias Syriaca And Other Asclepias Species, Heather Natterer

Undergraduate Honors Theses

In recent decades, Danaus plexippus (the monarch butterfly) has experienced a drastic decrease in population size due to urbanization, climate change, and habitat loss. The primary habitat and food source of D. plexippus is plant species that are within the genus Asclepias (milkweed). The preservation and propagation of Asclepias spp. is necessary to combat D. plexippus’s population declines. A plant’s reproductive success is dependent upon its ability to attract pollinators, which is linked to the plant’s nectar qualities. We propose that, in turn, these nectar qualities may be influenced by the nectar microbiome. This study aims to better understand the …

Lymphocyte Proteomics For Monitoring Long Term Immune System Dynamics, Michaela Mccown

Undergraduate Honors Theses

Time dependent change in lymphocytes provides a necessary background for monitoring the development of Chronic Lymphocytic Leukemia from asymptomatic to malignant. Several bulk proteomics studies characterize differences between tumor cells and healthy B cells, yet the transition to symptomatic disease is not well understood. This could be shown by a longitudinal study beginning with asymptomatic patients if the rare tumor cells in early stages can be isolated from small volume blood draws and effectively characterized with few cells, such as was done here using healthy B cells to provide a baseline for such studies to discriminate routine fluctuation from pathogenic …

Human Health And Economic Costs Of Air Pollution In Utah: An Expert Assessment, Isabella Errigo

Undergraduate Honors Theses

Recent scholarship has found that air pollution damages our health and economy more than previously understood, with approximately one in four deaths associated with exposure to air pollution globally. However, translating these research findings into policy and behavior change at local levels remains a major challenge, partially because of mismatch between the scale of air pollution research (often national or global) and governance frameworks (typically local to regional). Here, we used an expert assessment to bridge this research-policy divide in Utah, USA. We combined quantitative and qualitative input from 23 Utah-specific researchers and specialists, asking for estimates of human health …

Modeling Hybrid Novel Traits: A Case Study In Complex Petal Pigment Patterning In Hybrid Mimulus, Xingyu Zheng

Undergraduate Honors Theses

Hybridization between species, by introducing dramatic trait variation into the population and creating viable, transgressive offsprings with novel phenotypes, can have huge evolutionary implications. Some hybrid traits have been studied in the classical genetics or population genetics context, but most complex traits are determined by multiple causes, e.g. the number of loci involved, the rewiring of the genetic circuitries, and the changes in gene expression pattern. Using the hybrid monkeyflower petal pigment patterning as an example, we present a case study to investigate complex hybrid traits in a systematic manner that includes empirical data analysis and quantitative mathematical modeling of …

Modification, Verification Of Sequence And Optimization Of Expression Of P297f An Inactive Mutant Of Flavonol Specific Glucosyltransferase From Grapefruit (Cp3gt), Sarah Fox

Undergraduate Honors Theses

Citrus fruits are widely consumed and can offer various health benefits. One enzyme found in grapefruits, Citrus paradisi flavonol specific 3-O-glucosyltransferase (CP3GT), catalyzes the addition of glucose to one specific flavonoid class and at only one site. These flavonoids are plant secondary metabolites that can be used in a variety of plant functions including signaling and protection. The only class of flavonoids that CP3GT glucosylates is flavonols, and this specificity is of interest to study for potential benefits in biotechnology and enzyme modeling. In order to study this enzyme and its structure, a variety of mutants were created using site-directed …

Subcellular Localization Of Tobacco Sabp2 Under Normal And Stress Conditions, Sanjeev Das

Undergraduate Honors Theses

Subcellular Localization of Tobacco SABP2 under Normal and Stress Conditions

Salicylic acid (SA), a phytohormone, plays an important role in plant physiology. SA mediated innate immune pathway is an important pathway for plant immunity against pathogens. Plants resisting pathogen infection synthesize higher levels of Methyl Salicylate (MeSA), which is then converted to SA by the esterase activity of Salicylic Acid Binding Protein 2 (SABP2). The high level of the converted SA leads to enhanced pathogen resistance. The study of subcellular localization of a protein is critical in explaining its potential biochemical functions. SABP2 tagged with eGFP was expressed transiently in …

Plant Functional Groups And Success In A Changing Environment: Modeling Physiological Niches Of Colorado Plateau Plants, Anne Thomas

Undergraduate Honors Theses

Quantifying the environmental and physiological niches of plant species is crucial to predicting their sensitivity to global change, and aggregating plant species by functional type is fundamental both to ecological theory and to the practicality of large-scale efforts to predict the consequences of global change. However, traditional functional types are not always predictive of individual species’ responses to change. Here, an inverse species distribution modeling approach is used to identify functionally similar species based on physiological niche in order to better anticipate the consequences of climate change on the Colorado Plateau, USA. The Colorado Plateau is a semiarid region particularly …

Landscape Foundations: A Practical & Technical Guide To Landscape Maintenance, Marco Crosland

Undergraduate Honors Theses

Many homeowners struggle to maintain healthy landscapes. Often, they simply don’t understand basic principles that, if followed, would make a significant difference in the health and appearance of their landscape. The hope of Landscape Foundations is to help homeowners maintain healthy and excellent landscapes by teaching these “correct principles”.

What makes Landscape Foundations different than other landscape guides is that it brings in current research and explains it in a simple way. This guidebook provides pictures and additional resources to explain landscape maintenance principles. It teaches both the practical and technical sides.

Landscape Foundations is written for both beginners and …

Testing The Potential Of Novel Grain Crop Cultivation In Rural Malawi During The Dry Season Through Irrigation And Soil Modification, Jessica Truman

Undergraduate Honors Theses

This research project studied the germination and growth rates of oat and quinoa crops in Mtalimanja, Malawi. This project was part of a larger effort by General Mills and Brigham Young University researchers to increase the diversity and nutrient content of crops in impoverished countries worldwide. It was conducted from May to August 2017 during Malawi’s dry season. Tetraploid oats and quinoa, both modified to increase the protein content of harvested grains, were planted under three different soil conditions: unamended soil, soil mixed with composted chicken litter, and soil with surface-applied granular fertilizer. The research plots were watered daily except …

Identification Of N-Acylethanolamine Hydrolyzing Enzyme In Solanum Lycopersicum, Derek A. Stuffle

Undergraduate Honors Theses

N-acylethanolamines (NAEs) are fatty acid derivatives that occur naturally in plant and animal systems. In mammals, they regulate physiological functions, including neurotransmission, immune responses, vasodilation, embryo development and implantation, feeding behavior, and cell proliferation. NAEs are metabolized by fatty acid amide hydrolase (FAAH), which belongs to the amidase signature family. It is hypothesized that putative FAAH functions as the catalyst in the metabolism of N-acylethanolamine in tomato plants. To test the hypothesis, FAAH protein homologs were identified in tomato via in silico analysis. Among the six homologs identified, FAAH1 and FAAH2 were selected for further validation. This study …

Demography And Disease Of The Rare Shrub Buckleya Distichophylla (Santalaceae) In Northeastern Tennessee, William Seth Ratliff

Undergraduate Honors Theses

Piratebush (Buckleya distichophylla (Nutt.) Torr.) is a rare, hemiparasitic shrub with the only extant populations in western North Carolina, northeastern Tennessee, and southwestern Virginia. The preferred natural hosts of piratebush, Carolina and eastern hemlocks, have seen sharp declines over the last decade due to the invasive hemlock woolly adelgid. Virginia pine, another important host of piratebush, is also susceptible to disease, specifically Cronartium appalachianum, a rust fungus for which piratebush is the secondary host. This study described and analyzed current demographic parameters of three Tennessee piratebush populations. Additionally, spatial patterns of disease and demographic characters were analyzed. These …

Discovery Of Bald Cypress Fossil Leaves At The Gray Fossil Site, Tennessee And Their Ecological Significance., Sara Brandon

Undergraduate Honors Theses

This study focuses on fossil Taxodium leaves found at the Gray Fossil Site in northeastern Tennessee where many 7-4.5 million year old plants and animals have been recovered. Identification of the leaves is based on comparison of leaf morphology and confirmed by leaf anatomy. The ecological implications of the fossil are discussed to understand the paleoecology and paleoclimate at the Gray site. It is concluded that the fossil plant along with many other plants lived by a large sinkhole lake under a little warmer-than-today’s climate condition.

Impacts Of Goat Browsing And Disease On Lilium Grayi, Gray's Lily, On Roan Mountain., Joseph Powell

Undergraduate Honors Theses

The flora of southern Appalachian high elevation balds has strong representation of northern disjuncts and regional endemics. Among the endemics, the showy Lilium grayi (Gray’s Lily), is most noteworthy for its historical significance and for a high public profile. As bald vegetation changes in response to human and natural environmental shifts, active bald management has been implemented on public lands. Among managed balds, the Roan Mountain massif supports a large population of L. grayi. The purpose of this study was to describe the demography of adult plants, compare browsed and non-browsed plots, and determine the extent to which disease …