Life Sciences Commons^™

Heading For A Breakdown: Assessing Evolution Through The Hybridization Of Two Sexual Systems, Diamanda A. Zizis

Honors Theses

Hybridization is an important evolutionary pathway that has contributed to the world’s vast biodiversity. In plants, especially angiosperms, hybridization is known to be an important mechanism for speciation, phenotypic divergence, and changes in reproductive systems. Solanum species present an ideal system to investigate how hybridization between two different sexual systems impacts the reproductive and phenotypic biology of the hybrid progeny. Hybrid seeds were acquired from crosses between Australian Solanum species Solanum dioicum (dioecious) and S. ultraspinosum (andromonoecious) in order to track what happens when you cross two plants with different sexual systems. Vegetative and floral morphological measurements were conducted, and …

Changes In Ecosystem Processes And Functional Traits Over An Elevational Gradient, Tiana Issa

Honors Theses

Elevation gradients have been used to understand how climate change impacts various ecosystems processes by substituting distance across elevation with time, reflecting a previous, colder climate. To monitor the changes in soil organic carbon (SOC), plant community, and functional traits across time in the face of climate change, this study used space-for-time substitution to emulate a long-term study with elevational gradients and revisited the same gradient for nearly two decades to monitor elevational effects across time. With this research, I aim to answer the following questions: (1) How does elevation impact ecosystem processes and alpine plant traits? (2) How does …

Responses Of The Carnivorous Pink Spoonleaf Sundew (Drosera Capillaris) To Nitrogen Addition, Phosphorus Addition, And Simulated Fire, Karina Rodriguez Castillo

Honors Theses

This study investigated how the carnivorous plant, Drosera capillaris(pink sundew), responded to changes in the resources of its habitat, the fire-prone, nutrient-poor wet savannas. It is of interest to determine what soil nutrient(s), nitrogen or phosphorus, limits the survival and growth of pink sundew, and to what extent, if any, does fire affect the survival and growth of this carnivorous plant. My field experiments had twenty plots with two replicate groups consisting of four pink sundews in each plot. From the fall of 2017 to the fall of 2019, only half of the plots were clipped annually, and there …

The Importance Of A Multidisciplinary Approach To Public Health: Addressing Food Insecurity Through A Biological And Sociological Lens, Chloe Grant

Honors Theses

Plants can sense the change of 1 ^oC in their growth environment and thus global climate change has a great impact on plant growth and development. The phenomenon that warm non-stress temperatures promote stem and petiole elongation, as well as leaf hyponastic growth, is collectively known as thermomorphogenesis. While it is known that the basic helix-loop-helix (bHLH) transcription factor PIF4 is highly inducible by temperature elevations and controls thermomorphogenesis in dicots (e.g., Arabidopsis thaliana), the molecular mechanism underlying thermomorphogenetic growth in monocots is not clear. In this study, I identify PIF4 orthologs in several economically important monocotyledonous species and …

Transcriptional Activation Of Phytochrome-Interacting Factor 4 Is A Conserved Mechanism Of Thermomorphogenesis In Dicotyledenous Plants, Caroline Clutton

Honors Theses

In the model dicotyledonous plant Arabidopsis thaliana, the basic helix-loop-helix (bHLH) transcription factor Phytochrome-Interacting Factor 4 (AtPIF4) plays a central role in regulating the ambient temperature-regulated hypocotyl growth response. Warm temperatures induce AtPIF4 transcription and the accumulated AtPIF4 promotes thermomorphogenesis by enhancing the expression of a group of growth-related genes. However, whether this thermo-induced growth response is universal, and more importantly, whether there is a conserved thermomorphogenetic mechanism shared in dicots is largely unknown. Here we show that higher ambient temperatures promote the hypocotyl growth in four other dicotyledonous plants, including Brassica rapa, Camelina sativa, Nicotiana benthamiana …

A Contribution To The Macrofungi Of Cloudland Canyon State Park, Peyden Valentine

Honors Theses

I conducted a survey of the macroscopic fungi within Cloudland Canyon State Park, Dade County, GA that consisted of twenty-three forays from May through December of 2019, and one foray in March 2020. The results of my survey add baseline data to our knowledge of the mushrooms present within the park, allow for the future construction of an All Taxa Biodiversity Index, and allow comparisons to other surveys of fungal diversity in similar areas of the Cumberland Plateau: the Tennessee River Gorge Trust (Starrett 2005), and the Lula Lake Land Trust (De Guzman 2000). My survey resulted in an overall …

A Contribution To The Characterization Of The Diversity Of Ectomycorrhizal Fungi Associated With American Chestnut At The Utc Fortwood Street Nursery, Colton Jones

Honors Theses

Ectomycorrhizas play several essential roles in the biosphere and have immeasurable implications on the ecosystems in which they exist. Much has been discovered about the relationships between ectomycorrhizal fungi and the trees with which they associate, but there is still much to learn. Due to the nature of ectomycorrhizal morphology, DNA analysis is frequently required in order to accurately identify the fungal partner. Some ectomycorrhizal fungi produce above-ground fruiting bodies that presumably contain the same DNA sequences as the fungi encapsulating corresponding plant root tips below the soil; these fruiting bodies have been frequently observed growing in nursery containers at …

Use Of Co-Immunoprecipitations And 2d Gel Electrophoresis To Identify Protein-Protein Interactions Of Maturase K, Lauren Angello

Honors Theses

Maturase K (MatK) is the only group II intron encoded protein in the chloroplast of land plants. Maturases are prokaryotic enzymes that catalyze formation of the lariat structure needed for intron removal from precursor RNAs. The chloroplast maturase MatK, is a descendant of prokaryotic maturases, however, unlike its prokaryotic relatives, MatK is thought to catalyze excision of, not only its own intron, but also the introns of other group II introns in the plastome. Similar to the multiprotein and snRNA spliceosomal complex of the nucleus, it is postulated that MatK is not working alone to excise these introns but most …

Biological Soil Crusts In A Northeastern Pine Barren: Composition And Ecological Effects, Jessica Gilbert

Honors Theses

Biological soil crusts (BSCs), otherwise known as cryptogamic soil crusts, biocrusts, or cyanobacterial crusts, are soil aggregations hosting diverse biotic communities. They are composed of cyanobacteria and algae, and generally have a covering of moss and/or lichen. BSCs are typically found in arid to semi-arid regions throughout the world, and are integral soil stabilizers, moisture retainers, and nitrogen fixers in these communities. Along with these factors, BSCs are able to impact germination and establishment of plants, either as an accompanying influence, or direct result of those listed above. BSCs have yet to be formally described in the inland northeastern United …

Investigating Phosphorylation Patterns And Their Effect On The Activity Of Transcription Factor Taabf1 In Imbibing Cereal Grains, Grace Uwase

Honors Theses

The wheat transcription factor TaABF1 plays an important role in hormone-mediated regulation of seed dormancy and germination of cereal grains. Evidence shows that TaABF1 activity is regulated by phosphorylation, and previous work in our lab showed that when serine residues in its conserved regions; S36, S37, S113, S115 were altered to phosphomimetic aspartate, the 4xD TaABF1 mutant had increased activity as a transcription factor. However, when only S113 was altered, TaABF1’s activity was greatly reduced. The work presented here explored whether the S36D/S37D/S115D mutant would have stronger activity than the 4xD mutant. Using the particle bombardment technique to introduce the …

Organics: Exploring The Parallels Between Botany And Human Anatomy Through Sculpture And Watercolor Painting, Allison Borek

Honors Theses

Integrating my two passions of the visual arts and science for my senior thesis, I created a collection of paintings that represent human organs and the parallels between plant biology and animal biology. Genetically, plants are just as complex – if not more – than many animals. They have intricate sensory and regulatory systems highly comparable to humans, and on a cellular level, we share many analogous features. In addition, every single carbon atom that makes up the human body was at one time fixed in a plant during photosynthesis. We also rely on photosynthesis to give us the oxygen …

The Tradeoff Between Polyuronic Acid Content And Photosynthesis Rates In Sphagnum, Michael J. Danise

Honors Theses

Sphagnum mosses often dominate peatland ecosystems. Because of the low availability of nutrients in these environments, Sphagnum mosses have developed a cation exchange system within their cell walls to take up nutrients using polyuronic acids (PUA). Increasing amounts of PUA may come at a physiological tradeoff and cause decreasing photosynthetic rates. The objectives of this study were 1) to assess variation in polyuronic acid content and structure by analyzing component monomers from three different Sphagnum species representative of different microhabitats, 2) to investigate how this variation affects the cation exchange capacity of the peat moss species, and 3) to evaluate …

The Wheat Bzip Factor, Taabf1, Mediates Aba-Induced Gene Expression In Bombarded Barley Aleurone Layers, Benjamin R. Keyser

Honors Theses

The plant hormone Abscisic acid (ABA) plays a central role in maturation and germination in seeds, as well as mediating adaptive responses to abiotic environmental stresses. ABA induces the expression of many genes, including late-embryogenesis-abundant genes such as HVA1. To elucidate the ABA signaling pathway leading to HVA1 expression, we focus on the bZIP factor TaABF1. Analysis of the interplay between ABA and TaABF1 in the aleurone cells of imbibing cereal grains indicated that the two are not additive in their induction of the HVA1 promoter. A synthetic ABA analog, PBI-51, did not specifically inhibit the effect of exogenous ABA …

The Role Of Taabf1 In Abscisic Acid-Mediated Suppression Of 𝒶-Amylase Gene Expression In Cereal Grains, Lauren J. Harris

Honors Theses

The phytohormones gibberellin (GA) and abscisic acid (ABA) regulate important developments events in germinating seeds. Specifically, GA induces the expression of hyrolase genes, like the α-amylase gene Amy32b, which mobilizes starch reserves to be used by the embryo, and ABA suppresses this induction. Recent advancements identified ABA and GA receptors and key components in the signaling pathways, however, the mechanism of crosstalk between the hormones remains largely unknown. To further elucidate the mechanism of ABA suppression of GA-induced genes, we focused on the transcription factor TaABF1, a member of the ABA response element binding factor family. TaABF1 has been shown …

Stability Of Eukaryotic Elongation Factor One Alpha Protein In The Cell, Jennifer Watry

Honors Theses

Eukaryotic Elongation Factor One Alpha (eEF1A) is an abundant protein found in every cell of every organism and is involved in functions concerning protein synthesis and degradation, the cytoskeleton, and signaling. How these functions are regulated is not yet understood for this protein. Regulation of the protein may be controlled by transcription of the genes encoding the protein or the stability and modification of the protein. The goal of this project was to determine the stability of eEf1A proteins in Arabidopsis thaliana. Protein stability was determined by treating tissues with cycloheximide, an inhibitor of protein synthesis. Gel electrophoresis and …

The Effects Of Rose Bengal Application On The Production Of Salicylic Acid In Nahg Tobacco Plants, Nicole Christine Ott

Honors Theses

Plants have the ability to develop resistance to a wide range of pathogens following exposure to a single bacterium, fungus, or virus. This resistance occurs in all tissues, not only those that were previously infected. This mechanisms is termed systemic acquired resistance (SAR). The phenolic compound salicylic acid (SA) has been linked to SAR in tobacco, arabidopsis, and cucumber plants. Oxidative stress also causes SA production, which leads to SAR. An engineered tobacco plant (nahG) that does not have the ability to accumulate SA has been used as a research tool in investigations concerning SA activity. Rose Bengal …

Plant Galls, Michael Paul Grisham

Honors Theses

Plant galls, or cedidia, are defined as

...pathologically developed cells, tissues, or organs of plants that have risen mostly by hypertrophy and hyperplasy under the influence of parasitic organisms like bacteria, fungi, nematoda, mites, or insects.

The plant gall is unique in providing not only food, but shelter as well for its host. While the host benefits, damage to the plant results. Among other things sap flow is disturbed, premature decay results, non-essential parts are developed at the cost of essential parts, and many other injuries occur. A few examples of the benefits of plan galls may be cited. Nitrogen …