Biology Commons^™

Bryophyte Assemblages On American Hornbeam (Carpinus Caroliniana) And The Surrounding Arboreal Communities Within The Forest Of East Texas, Cassey Edwards

Electronic Theses and Dissertations

The bryophytes, the non-vascular plants, include the mosses (Bryophyta with approximately 13,000 species), the liverworts (Marchantiophyta with approximately 5,000 species), and the hornworts (Anthocerotophyta with approximately 150 species). Initial observations indicated that the midstory tree Carpinus caroliniana Walter (American hornbeam) has a bryophyte composition with an unusually high diversity of leafy liverworts. Voucher samples were taken from the four intercardinal directions (Northeast, Northwest, Southwest, and Southeast) from six Carpinus trees and their nearest neighbor that was neither Pinus nor another Carpinus at each of six sites across East Texas. Percent coverage, species richness, Shannon’s diversity and Pielou’s evenness were computed. …

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

Science and Technology Department Faculty Journal Articles

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

Modeling Effects Of Ecological Factors On Evolution Of Polygenic Pesticide Resistance, C. V. Haridas, Brigitte Tenhumberg

School of Biological Sciences: Faculty Publications

Widespread use of pesticides has resulted in the evolution of resistance in many insect pests worldwide, limiting their use in pest control. Effective pest and resistance management practices require understanding of the genetics of resistance and the life history of the pest. Most models for pesticide resistance assume that resistance is monogenic, conferred by a single gene. However, resistance could evolve as a polygenic quantitative trait resulting from the action of several genes, especially when pesticide dose is low. Further, fitness of the pest could be density dependent and might depend upon abiotic factors such as temperature. It is not …

Plant Litter Quality Affects The Accumulation Rate, Composition, And Stability Of Mineral-Associated Soil Organic Matter, S. Carolina Córdova, Dan C. Olk, Ranae N. Dietzel, Kevin E. Mueller, Sotirios V. Archontouilis, Michael J. Castellano

Biological, Geological, and Environmental Faculty Publications

Mineral-associated organic matter (MAOM) is a relatively large and stable fraction of soil organic matter (SOM). Plant litters with high rates of mineralization (high quality litters) are hypothesized to promote the accumulation of MAOM with greater efficiency than plant litters with low rates of mineralization (low-quality litters) because litters with high rates of mineralization maximize the synthesis of microbial products and most MAOM is microbial-derived. However, the effect of litter quality on MAOM is inconsistent. We conducted four repeated short-term incubations (46-d each) of four plant litters (alfalfa, oats, maize and soybean) in two low-carbon subsoils (sandy loam and silty …

The Effects Of Seawater Temperature On Photosynthesis In Crustose Coralline Algae, Alexander Carlson

Independent Study Project (ISP) Collection

Crustose Coralline Algae (CCA) are prolific reef builders and primary producers that play a key role in maintaining the structural integrity of coral reef systems (Littler and Littler, 2013). They are also highly important in increasing reef resilience by serving as a substrate for the recruitment and metamorphosis of coral larvae (Chisholm, 2000). Little is known about the way in which increasing seawater temperatures due to climate change might affect metabolic rates like photosynthesis in CCA. Therefore, a study was carried out in November, 2018, in the lab at Lizard Island Research Station to explore the photosynthetic performance of a …

Structural Basis For Light Control Of Cell Development Revealed By Crystal Structures Of A Myxobacterial Phytochrome, Nicole C. Woitowich, Andrei S. Halavaty, Patricia Waltz, Christopher Kupitz, Joseph Valera, Gregory Tracy, Kevin D. Gallagher, Elin Claesson, Takanori Nakane, Suraj Pandey, Garrett Nelson, Rie Tanaka, Eriko Nango, Eiichi Mizohata, Shigeki Owada, Kensure Tono, Yasumasa Joti, Angela C. Nugent, Hardik Patel, Ayesha Mapara, James Hopkins, Phu Duong, Dorina Bizhga, Svetlana E. Kovaleva, Rachel St. Peter, Cynthia N. Hernandez, Wesley B. Ozarowski, Shatabdi Roy-Chowdhuri, Jay-How Yang, Petra Edlund, Heikki Takala, Janne Ihalainen, Jennifer Brayshaw, Tyler Norwood, Ishwor Poudyal, Petra Fromme, John C.H. Spence, Keith Moffat, Sebastian Westenhoff, Marius Schmidt, Emina A. Stojkovic

Biology Faculty Publications

Phytochromes are red-light photoreceptors that were first characterized in plants, with homologs in photosynthetic and non-photosynthetic bacteria known as bacteriophytochromes (BphPs). Upon absorption of light, BphPs interconvert between two states denoted Pr and Pfr with distinct absorption spectra in the red and far-red. They have recently been engineered as enzymatic photoswitches for fluorescent-marker applications in non-invasive tissue imaging of mammals. This article presents cryo- and room-temperature crystal structures of the unusual phytochrome from the non-photosynthetic myxobacterium Stigmatella aurantiaca (SaBphP1) and reveals its role in the fruitingbody formation of this photomorphogenic bacterium. SaBphP1 lacks a conserved histidine (His) in the chromophore-binding …

Laboratory Evaluation Of Efficacy Of Entomopathogenic Nematodes On Texas Leaf-Cutting Ants, Atta Texana, Pushpa Soti, Quentin Van Camp, Alexis Racelis

School of Integrative Biological & Chemical Sciences (Formerly Dept. of Biology)

Entomopathogenic nematodes, a large group of nematodes specialized for parasitism of insects, have been used as classical biological control agents. The nematodes have potential to be used for insect pest management in organic gardening. We studied the potential impact of two entomopathogenic nematodes Steinerneima carpocapsae Weiser and Heterohabditis bacteriophora Poinar on the Texas leaf-cutting ant, Atta texana Buckley, that is considered a problematic agricultural pest in the southern US. We used a relatively large exposure rate of 250,000 nematodes per 10 ants in Petri dishes and monitored ant activity during a 96-hour time period. Results showed no significant differences among …

Mobile Elements Shape Plastome Evolution In Ferns, Tanner A. Robison, Amanda L. Grusz, Paul G. Wolf, Jeffrey P. Mower, Blake D. Fauskee, Karla Sosa, Eric Schuettpelz

Biology Faculty Publications

Plastid genomes display remarkable organizational stability over evolutionary time. From green algae to angiosperms, most plastid genomes are largely collinear, with only a few cases of inversion, gene loss, or, in extremely rare cases, gene addition. These plastome insertions are mostly clade-specific and are typically of nuclear or mitochondrial origin. Here, we expand on these findings and present the first family-level survey of plastome evolution in ferns, revealing a novel suite of dynamic mobile elements. Comparative plastome analyses of the Pteridaceae expose several mobile open reading frames that vary in sequence length, insertion site, and configuration among sampled taxa. Even …

Ectopic Expression Of A Stilbenoid Prenyltransferase From Peanut In Hairy Roots Of Muscadine Grape, Mohammad Fazle Azim

Student Theses and Dissertations

Stilbenoids are phenolic compounds which not only serve as phytoalexins but also exhibit biological activities important to human health, including anticancer, anti-inflammatory and neuroprotective properties in vitro. However, some stilbenoids, such as the non prenylated stilbenoid resveratrol, have poor bioavailability limiting their application in vivo. Therefore, the goal of this project was to express a peanut stilbenoid prenyltransferase (i.e. AhR4DT-1) in muscadine grape to convert resveratrol to the prenylated stilbenoid arachidin-2, a potentially more bioavailable stilbenoid than resveratrol. Four hairy root lines of muscadine grape were developed via transformation with an engineered Agrobacterium rhizogenes harboring a peanut stilbenoid prenyltransferase. The …

Yardwork: A Biography Of An Urban Place By Daniel Coleman, Vivian M. Hansen

The Goose

Review of Daniel Coleman's Yardwork: A Biography of an Urban Place.

Why Large Seeds With Physical Dormancy Become Nondormant Earlier Than Small Ones, Ailton G. Rodrigues-Junior, Ana Caroline M. P. Mello, Carol C. Baskin, Jerry M. Baskin, Denise M. T. Oliveira, Queila S. Garcia

Biology Faculty Publications

Under natural conditions, large seeds with physical dormancy (PY) may become water permeable earlier than small ones. However, the mechanism for this difference has not been elucidated. Thus, our aim was to evaluate the traits associated with PY in seeds of Senna multijuga (Fabaceae) and to propose a mechanism for earlier dormancy-break in large than in small seeds. Two seedlots were collected and each separated into large and small seeds. Seed dry mass, water content, thickness of palisade layer in the hilar and distal regions and the ratio between palisade layer thickness (P) in the lens fissure and seed mass …

Genetic Diversity In An Invasive Clonal Plant? A Historical And Contemporary Perspective, Elliot D. Weidow

LSU New Orleans Theses and Dissertations

Introduced populations of Eichhornia crassipes (Pontederiaceae) possess extremely low levels of genetic diversity due to severe bottleneck events and clonal reproduction. While populations elsewhere have been well studied, North American populations of E. crassipes remain understudied. We used Amplified Fragment Length Polymorphism markers to assess genetic diversity and population structure in North American E. crassipes populations. Patterns of diversity over the past fifty years were analyzed using herbarium specimens. Furthermore, we sampled populations across the Gulf Coast of the United States throughout a year to determine contemporary genetic diversity and assess potential seasonal effects. Genetic diversity was found to be …

A Student’S Perspective On Engagement In Ecological Research During Their First Semester In College, Natalie M. Aguirre, Karagan L. Smith, Cristian M. Garcia, Cheryl Swift, Stephen D. Davis

Biology

Pepperdine University and Whittier College jointly initiated a new first-year seminar series in the fall of 2016 that engaged students in authentic research, their first semester on campus. The goals are listed below. Assessment of these goals included both qualitative focus groups and quantitative survey questionnaires administered by an outside assessment agency, WestEd.org.

Ninety-two percent of students reported that their first-year seminar improved learning in concurrent courses and ninety to ninety-three percent of students said their first-year seminar increased their interest in STEM. In addition, students self-reported a significant improvement in all aspects of their ability to plan and conduct …

Post Drought Recovery In Malosma Laurina After Severe Dieback During California’S Historic Drought Of 2012-2016, Karagan L. Smith, Guinevere X. Mesh, Natalie M. Aguirre, Gabriella N. Palmeri, Helen I. Holmlund, Stephen D. Davis

Biology

Malosma laurina is a species of chaparral shrub that dominates coastal exposures of the Santa Monica Mountains of southern California. Between 2012 and 2016, protracted drought with half normal rainfall over a five-year period (175 mm), led to severe dieback, exceeding 50% whole plant mortality at some sites. The drought dissipated in 2017 with an annual rainfall that exceeded the 140-yr normal by 108 mm. As a result of this elevated annual rainfall in 2017, we were interested in documenting the potential for full recovery of Malosma laurina as a keystone species of coastal chaparral shrub communities. We tested the …

Expression Of Carbohydrates Biosynthetic Genes In Developing Soybean Seeds, Jayden Rosen, Karen A. Hudson

The Summer Undergraduate Research Fellowship (SURF) Symposium

An essential part of livestock diets is soybean meal, which is a major source of protein, but which also consists of antinutritional carbohydrates. Antinutritional carbohydrates such as raffinose and stachyose lead to irritation to the gut for monogastric livestock as well as unhealthy weight gain. A major objective of soybean genetics is to reduce these antinutritional carbohydrates within the seed and increase the levels of good carbohydrates. This will lead to healthier livestock and better meat quality. To select genes potentially responsible for variation in carbohydrate levels in seeds, the expression of genes encoding several biosynthetic enzymes was measured during …

Fungal Endophyte Alternaria Tenuissima Can Affect Growth And Selenium Accumulation In Its Hyperaccumulator Host Astragalus Bisulcatus, Stormy D. Lindblom, Ami L. Wangeline, Jose R. Valdez Barillas, Berthal Devilbiss, Sirine C. Fakra, Elizabeth A. H. Pilon-Smits

Biology Faculty Publications (Archived)

Endophytes can enhance plant stress tolerance by promoting growth and affecting elemental accumulation, which may be useful in phytoremediation. In earlier studies, up to 35% elemental selenium (Se⁰ ) was found in Se hyperaccumulator Astragalus bisulcatus. Since Se⁰ can be produced by microbes, the plant Se⁰ was hypothesized to be microbe-derived. Here we characterize a fungal endophyte of A. bisulcatus named A2. It is common in seeds from natural seleniferous habitat containing 1,000– 10,000 mg kg^-1 Se. We identified A2 as Alternaria tenuissima via 18S rRNA sequence analysis and morphological characterization. X-ray microprobe analysis of A. …

Field Data On Plant Growth And Insect Damage On The Noxious Weed Solanum Eleaegnifolium In An Unexplored Native Range, Rupesh R. Kariyat, Jesus Chavana

School of Integrative Biological & Chemical Sciences (Formerly Dept. of Biology)

In this data article, we provide a novel data set on plant growth, insect damage levels, and herbivore community of the noxious and invasive weed Solanum eleaegnifolium (Solanaceae). The data is collected from disturbed and un-disturbed urban populations of the species from one of its unexplored native range in Southern United States (South Texas). The data include plant height measurements, insect damage levels, GPS coordinates of the populations, and their disturbance status. Additional data includes the number of chewing herbivore (specialist herbivore Texas potato beetle (Leptinotarsa texana; Chrysomelidae), their eggs, and any lepidopteran caterpillars found on the plants.

The Fate Of Xylem-Transported Co2 In Plants, Samantha S. Stutz, David T. Hanson

Biology ETDs

The concentration of carbon dioxide in tree stems can be ~30-750 times higher than current atmospheric [CO2]. Dissolved inorganic carbon enters the xylem from root and stem respiration and travels with water through the plant. However, the fate of much of this xylem-transported CO2 is unknown. In these studies I examined the fate of xylem-transported CO2 traveling through the petiole and leaf. This was accomplished by placing cut leaves from a woody and herbaceous C3 species, and a Kranz-type C4 species, in a solution of dissolved NaH13CO3 at concentrations similar to those measured in nature. This allowed me to track …

Floristic Survey Of Crawford And Cherokee Counties In Southeast Kansas: An Evaluation Of Change Over Five Decades, Samantha Pryer

Electronic Theses & Dissertations

This project had two main objectives. The first objective was to document comprehensively the vascular flora of Crawford and Cherokee counties in extreme southeast Kansas. Each county had seen limited collecting in recent decades, though a comprehensive survey had never been done for Cherokee County. PSU student E.S. Gibson summarized the flora for Crawford County in 1963. Fieldwork for the present study occurred mostly in 2014 and 2015. Based on 6500+ newly collected specimens, vouchers from Gibson’s study, and taxa documented by Biota of North America (BONAP) (Kartesz 2017), 1440 taxa are reported, which includes 33 state and 263 county …

Apiaceae Of Northcentral New Mexico, Asha Hamaker

Northcentral New Mexico Plants Specimen Collection, 2018

No abstract provided.

High Dispersal Ability Is Related To Fast Life-History Strategies, Noelle G. Beckman, James M. Bullock, Roberto Salguero-Gomez

Ecology Center Publications

1. Seed dispersal is an essential, yet often overlooked process in plant ecology and evolution, affecting adaptation capacity, population persistence and invasiveness. A species’ ability to disperse is expected to covary with other life-history traits to form dispersal syndromes. Dispersal might be linked to the rate of life history, fecundity or generation time, depending on the relative selection pressures of bethedging, kin competition or maintaining gene flow. However, the linkage between dispersal and plant life-history strategies remains unknown because it is difficult to observe, quantify and manipulate the influence of dispersal over large spatiotemporal scales.

2. We integrate datasets describing …

Nonpolar Residues In The Presumptive Pore‐Lining Helix Of Mechanosensitive Channel Msl10 Influence Channel Behavior And Establish A Nonconducting Function, Grigory Maksaev, Jennette K. Shoots, Simran Ohri, Elizabeth S. Haswell

Biology Faculty Research

Mechanosensitive (MS) ion channels provide a universal mechanism for sensing and responding to increased membrane tension. MscS‐like (MSL) 10 is a relatively well‐studied MS ion channel from Arabidopsis thaliana that is implicated in cell death signaling. The relationship between the amino acid sequence of MSL10 and its conductance, gating tension, and opening and closing kinetics remains unstudied. Here, we identify several nonpolar residues in the presumptive pore‐lining transmembrane helix of MSL10 (TM6) that contribute to these basic channel properties. F553 and I554 are essential for wild type channel conductance and the stability of the open state. G556, a glycine residue …

Radical Social Ecology As Deep Pragmatism: A Call To The Abolition Of Systemic Dissonance And The Minimization Of Entropic Chaos, Arielle Brender

Student Theses 2015-Present

This paper aims to shed light on the dissonance caused by the superimposition of Dominant Human Systems on Natural Systems. I highlight the synthetic nature of Dominant Human Systems as egoic and linguistic phenomenon manufactured by a mere portion of the human population, which renders them inherently oppressive unto peoples and landscapes whose wisdom were barred from the design process. In pursuing a radical pragmatic approach to mending the simultaneous oppression and destruction of the human being and the earth, I highlight the necessity of minimizing entropic chaos caused by excess energy expenditure, an essential feature of systems that aim …

Target Sequence Capture Of Nuclear-Encoded Genes For Phylogenetic Analysis In Ferns, Paul G. Wolf, Tanner A. Robison, Matthew G. Johnson, Michael A. Sundue, Weston L. Testo, Carl J. Rothfels

Biology Faculty Publications

Premise of the Study

Until recently, most phylogenetic studies of ferns were based on chloroplast genes. Evolutionary inferences based on these data can be incomplete because the characters are from a single linkage group and are uniparentally inherited. These limitations are particularly acute in studies of hybridization, which is prevalent in ferns; fern hybrids are common and ferns are able to hybridize across highly diverged lineages, up to 60 million years since divergence in one documented case. However, it not yet clear what effect such hybridization has on fern evolution, in part due to a paucity of available biparentally inherited …

The Influence Of Agricultural Activities On The Diversity Of Rodents In Kindoroko Forest Reserve And Surrounding Areas, North Pare Mountains, Tanzania, Remmy Lema, Flora J Magige

Tanzania Journal of Science

The patterns of richness, diversity and similarity in rodent communities in agricultural areas and in adjacent Kindoroko Forest Reserve in the North Pare Mountains, Tanzania were assessed. By using a capture-mark-recapture method, 289 individuals of nine rodent species in March and May 2011 were captured. Seven species were recorded in agricultural area and 5 species in the Forest Reserve. Multimammate Rat (Mastomys natalensis) was abundant in agricultural area while soft-furred mouse (Praomys delectorum) was dominant in the Forest Reserve. Species diversity was greater outside than inside the forest, supporting results of earlier studies. Species similarity between the two habitats was …

In Vitro Antimicrobial Activity Of Extracts Of Some Plant Species Used In The Management Of Hiv/Aids In Tanzania, Cyprian Beda Mpinda, Debra Meyer, Sylvester Leonard Lyantagaye

Tanzania Journal of Science

Six plants species (Harungana madagascariensis, Sapium ellipticum, Teclea nobilis, Pseudospondias microcarpa, Rauvolfia vomitoria and Psorospermum febrifugum) which are used in managing HIV/AIDS in Bukoba, Tanzania were screened for their antimicrobial effect on the selected representatives of infectious bacterial and fungal species. Gram-positive bacteria Streptococcus lactis, Gram-negative bacteria Klebsiella pneumoniae and a fungus Candida albicans were tested for their sensitivity to the treatment with selected plants extracts using disc diffusion and broth dilution techniques. Extracts of S. ellipticum, P. febrifegum and P. microcarpa demonstrated growth inhibition of S. lactis with the MIC ranging from 3.2 to 100 mg/ml. The extracts of …

Seasonal Leaf Structure And Function Tradeoffs In Native And Invasive Shrubs, Lauren Woolhiser

Renée Crown University Honors Thesis Projects - All

The spread of invasive alien plants continues to raise the overall threat to biodiversity around the world. The Enemy Release Hypothesis indicates that invasive alien plants are less regulated by natural enemies when introduced to a region (Keane and Crawley, 2002). Due to this, I hypothesize that invasive plants have more flexibility to allocate to photosynthetic ability, while native plants are required to allocate to structural defense in order to defend against more enemy regulation. To test this, woody shrub species leaves were collected and tested for nitrogen/carbon content, chlorophyll content, photosystem quantum efficiency, and fiber analysis across three seasons. …

Progress And Potential Of Two Biological Control Agents Of The Invasive Giant Reed (Arundo Donax L.), Madeline Marshall

Theses and Dissertations

Biological control, or the use of natural enemies for pest management, may the best long-term option for managing the invasive Arundo donax , a noxious weed dominating riparian habitats globally and along the Rio Grande River. This work reports on the progress and potential of two arundo biological control agents permitted for release in Texas and Mexico. The arundo wasp, Tetramesa romana, released in 2009, is having significant impacts as reported from various field locations around the world, described here using standard exit hole counts. The highest density levels were found in Texas (introduced range) compared to relatively low …

Leaf Trichomes Affect Caterpillar Feeding In An Instar-Specific Manner, Rupesh R. Kariyat, Sean B. Hardison, Aisling B. Ryan, Andrew G. Stephenson, Consuelo M. De Moraes, Mark C. Mescher

School of Integrative Biological & Chemical Sciences (Formerly Dept. of Biology)

Leaf trichomes play well-established roles in defense against insect herbivores, both as a physical barrier that impedes herbivore movement and by mediating chemical defenses. However, little work has examined how different trichome types influence herbivory by herbivores at different stages of development. We examined whether caterpillar instar and trichome type (glandular or non-glandular) affected the ability of the specialist herbivore caterpillar Manduca sexta to initiate feeding on 11 Solanaceous species exhibiting variation in the density and type of leaf trichomes. Our results suggest that non-glandular trichomes are far more effective than glandular trichomes in deterring the initiation of feeding by …

A Contribution Toward A Global Monograph Of Gyroporus: Taxonomy, Phylogeny, Biogeography, Naveed Davoodian

Dissertations, Theses, and Capstone Projects

Gyroporus (Sclerodermatineae, Boletales, Agaricomycetes, Basidiomycota, Fungi) is a genus of ectomycorrhizal mushroom-forming fungi distributed throughout the world in suitable habitats. Previous attempts to untangle the diversity of this genus proved difficult due to the presence of semi-cryptic species and equivocal results from phylogenetic analysis of ribosomal RNA markers. To overcome these obstacles, a combined taxonomic and phylogenetic (emphasizing protein-coding genes) approach is used here to delimit species and elucidate geographic and evolutionary patterns of Gyroporus. Careful study of relevant literature and herbarium specimens was augmented by field work in North America, Australia, and East Asia for observation and collection …