Plant Biology Commons^™

Floral Symmetry Genes Elucidate The Development And Evolution Of Oil-Bee Pollinated Flowers Of Malpighiaceae And Krameriaceae, Farahnoz N. Khojayori

Theses and Dissertations

Specialization on insect and animal pollinators is thought to be the driving force for the evolution of floral traits. Specifically in the New World (NW), the oil-bee pollination syndrome has led to the convergence of floral characters in two distantly related families of core eudicots, Malpighiaceae and Krameriaceae. Both families display a flag-like structure that establishes a zygomorphic flower and floral oil rewards in epithelial elaiophores. These traits work concomitantly to attract and reward female oil-bees that help fertilize these flowers and in return receive oils. The underlying genetics of floral zygomorphy were studied in several clades of core eudicots, …

Expression Analyses And Identification Of Key Molecular Participants In Plant Responses To Environmental Cues, Praveena Kanchupati

Electronic Theses and Dissertations

Plants constantly engage and interact with the environment and respond to the changes in conditions like temperature, water, and photoperiod, by regulating expression of genes of multiple regulatory and signaling pathways. Insight into these pathways and their participants has provided and will provide candidates to improve various agronomically important traits in crops through marker-assisted breeding and genetic manipulation. With this aim in mind, in the present study, I attempted to identify key candidate genes that are involved in the regulation of; i) plant response to low temperature stress, ii) plant roots’ response to soil moisture content and iii) flowering time. …

Regulation Of Local Auxin Metabolism During Soybean Nodule Development, Suresh Damodaran

Electronic Theses and Dissertations

Legume-rhizobia symbiosis leads to the development of secondary root organs called nodules. Rhizobia bacteria housed inside nodules assimilate atmospheric nitrogen and convert them into plant usable forms thereby reducing the need for fertilizer application in crop legumes like soybean. Nodule development is a coordinated process orchestrated by multiple plant hormones. In soybean, the auxin responsive gene expression was detected in nodule primordia and in the periphery of mature nodules, primarily in nodule vasculature. Auxin hypersensitivity reduces nodule formation in soybean and also polar auxin transport inhibition at the site of nodule development is not crucial for determinate nodule formation. Therefore, …

Identification Of Qtl Modifying The Activity Of The Tcb1-S Locus And Characterization And Sequencing Of Two Plutonium-Beryllium Induced Reduced Gametophyte Transmission Mutants In Maize, Merritt Bryer Burch

Electronic Theses and Dissertations

This thesis is split into two independent projects both involving the male gametophyte generation of maize. The first project looks at how pollen interacts with the female gametophyte to reduce its transmission in cross-incompatible reactions controlled by the unilateral cross-incompatibility system, teosinte crossing barrier 1. The second project explores two plutonium-beryllium induced male gametophyte mutants and attempts to uncover their genetic basis.

Identification of QTL Modifying the Activity of the Tcb1-s Locus
Teosinte crossing barrier 1 (Tcb1) is a unilateral cross-incompatibility system present in maize that provides a pre-zygotic pistil barrier to plants carrying Tcb1-s (strong allele) from pollen …

The Role Of Environmental Filtering In Structuring Appalachian Tree Communities: Topographic Influences On Functional Diversity Are Mediated Through Soil Characteristics, Julia I. Chapman, Ryan W. Mcewan

Biology Faculty Publications

Identifying the drivers of community assembly has long been a central goal in ecology, and the development of functional diversity indices has provided a new way of detecting the influence of environmental gradients on biotic communities. For an old-growth Appalachian forest, we used path analysis to understand how patterns of tree functional diversity relate to topography and soil gradients and to determine whether topographic effects are mediated through soil chemistry. All of our path models supported the idea of environmental filtering: stressful areas (high elevation, low soil moisture, low soil nutrients) were occupied by communities of low functional diversity, which …

Natural And Anthropogenic Drivers Of Tree Evolutionary Dynamics, Brandon M. Lind

Theses and Dissertations

Species of trees inhabit diverse and heterogeneous environments, and often play important ecological roles in such communities. As a result of their vast ecological breadth, trees have become adapted to various environmental pressures. In this dissertation I examine various environmental factors that drive evolutionary dynamics in threePinusspecies in California and Nevada, USA. In chapter two, I assess the role of management influence of thinning, fire, and their interaction on fine-scale gene flow within fire-suppressed populations of Pinus lambertiana, a historically dominant and ecologically important member of mixed-conifer forests of the Sierra Nevada, California. Here, I find evidence …

Conflicting Hydraulic Effects Of Xylem Pit Structure Relate To The Growth-Longevity Tradeoff In A Conifer Species, Beth Roskilly

Graduate Student Theses, Dissertations, & Professional Papers

Consistent with a ubiquitous life history tradeoff, trees exhibit a negative relationship between growth and longevity among and within species. However, the mechanistic basis of this life history tradeoff is not well understood. In addition to tradeoffs among multiple traits based on resource allocation conflicts, life history tradeoffs may arise from tradeoffs based on single traits under opposing selection. While a myriad of factors likely contribute to the growth-longevity tradeoff in trees, we hypothesized that conflicting functional effects of xylem structural traits contribute to the growth-longevity tradeoff. We tested this hypothesis by examining the extent to which xylem morphological traits …

The Three Creeks Allotment Consolidation: Changing Western Federal Grazing Paradigms, Taylor Payne

Human–Wildlife Interactions

The federal government owns approximately 47% of all land in the western United States. In the state of Utah, about 64% of the land base is managed by the federal Bureau of Land Management (BLM) and the U.S. Forest Service (USFS). The government has historically issued permits to owners of private lands to allow the owners to graze their livestock on public lands. The permits (allotments) are generally of 10-year duration and allow for an annual season of use. In some cases, continued and repeated historical annual grazing practices may not be ideal for permit holders and their communities nor …

Phyllotactic Regularity Requires The Paf1 Complex In Arabidopsis, Kateryna Fal, Mengying Liu, Assem Duisembekova, Yassin Refahi, Elizabeth S. Haswell, Olivier Hamant

Biology Faculty Research

In plants, aerial organs are initiated at stereotyped intervals, both spatially (every 137° in a pattern called phyllotaxis) and temporally (at prescribed time intervals called plastochrons). To investigate the molecular basis of such regularity, mutants with altered architecture have been isolated. However, most of them only exhibit plastochron defects and/or produce a new, albeit equally reproducible, phyllotactic pattern. This leaves open the question of a molecular control of phyllotaxis regularity. Here, we show that phyllotaxis regularity depends on the function of VIP proteins, components of the RNA polymerase II-associated factor 1 complex (Paf1c). Divergence angles between successive organs along the …

Phylogenetic Patterns Of Foliar Mineral Nutrient Accumulation Among Gypsophiles And Their Relatives In The Chihuahuan Desert, Clare Muller, Michael J. Moore, Zoe Feder, Helene Tiley, Rebecca E. Drenovsky

2017 Faculty Bibliography

PREMISE OF THE STUDY: Gypsum endemism in plants (gypsophily) is common on gypsum outcrops worldwide, but little is known about the functional ecology of Chihuahuan Desert gypsophiles. We investigated whether leaf chemistry of gypsophile lineages from the northern Chihuahuan Desert are similar to leaves of related nonendemic (gypsovag) species relative to their soil chemistry. We expected widely distributed gypsophiles (hypothesized to be older lineages on gypsum) would have distinct leaf chemistry from narrowly distributed, relatively younger lineages endemic to gypsum and gypsovags, reflecting adaptation to gypsum.

METHODS: We collected leaves from 23 gypsophiles and related nonendemic taxa growing on nongypsum …

Characterization Of A Novel Mitochondrial Plasmid In Brassica, Mackenzie Strehle

UCARE: Research Products

Possessing some of the largest and most complex genomes of any eukaryotic organelles, plant mitochondria are notorious for their rapidly rearranging genetic framework. In addition to containing a large and complex mitochondrial genome, the mitochondria of several plants in the genus Brassica have also been shown to contain an independent, self-replicating linear plasmid. Interestingly, the plasmid appears to be able to move independently between the cytoplasm and the mitochondria, and it can be paternally inherited, unlike the rest of the mitochondrial genome. The plasmid also has features similar to those of adenoviruses, including terminal inverted repeats and covalently bound proteins …

Photosensing And Thermosensing By Phytochrome B Require Both Proximal And Distal Allosteric Features Within The Dimeric Photoreceptor, E Sethe Burgie, Adam N. Bussell, Shu-Hui Lye, Tong Wang, Weiming Hu, Katrice E. Mcloughlin, Erin L. Weber, Huilin Li, Richard D. Vierstra

Biology Faculty Research

Phytochromes (Phys) encompass a diverse collection of bilin-containing photoreceptors that help plants and microorganisms perceive light through photointerconversion between red light (Pr) and far-red light (Pfr)-absorbing states. In addition, Pfr reverts thermally back to Pr via a highly enthalpic process that enables temperature sensation in plants and possibly other organisms. Through domain analysis of the Arabidopsis PhyB isoform assembled recombinantly, coupled with measurements of solution size, photoconversion, and thermal reversion, we identified both proximal and distal features that influence all three metrics. Included are the downstream C-terminal histidine kinase-related domain known to promote dimerization and a conserved patch just upstream …

Plant Mechanosensitive Ion Channels: An Ocean Of Possibilities, Debarati Basu, Elizabeth S. Haswell

Biology Faculty Research

Mechanosensitive ion channels, transmembrane proteins that directly couple mechanical stimuli to ion flux, serve to sense and respond to changes in membrane tension in all branches of life. In plants, mechanosensitive channels have been implicated in the perception of important mechanical stimuli such as osmotic pressure, touch, gravity, and pathogenic invasion. Indeed, three established families of plant mechanosensitive ion channels play roles in cell and organelle osmoregulation and root mechanosensing - and it is likely that many other channels and functions await discovery. Inspired by recent discoveries in bacterial and animal systems, we are beginning to establish the conserved and …

The Impact Of Climate And Elevation On The Growth And Mortality Of Piñon Pine, Alice M. Fretz

Biology ETDs

The Southwestern United States is currently experiencing severe drought, resulting in the mortality of many tree species. Piñon-juniper woodlands are an extensive biome in the Southwest, and are highly vulnerable to extended periods of drought that lead to tree mortality. Specifically, Pinus edulis populations are decreasing due to increasingly arid conditions. I used dendrochronology to investigate how tree growth rings of Pinus edulis reflect severe drought in living and dead trees. I also investigated how severe drought affects Pinus edulis along an altitudinal gradient. Tree core samples were taken from currently living and dead trees, as well as from trees …

Cellular And Molecular Targets Of Menthol Actions, Murat Oz, Eslam El Nebrisi, Keun-Hang Susan Yang, Frank Christopher Howarth, Lina T. Al Kury

Mathematics, Physics, and Computer Science Faculty Articles and Research

Menthol belongs to monoterpene class of a structurally diverse group of phytochemicals found in plant-derived essential oils. Menthol is widely used in pharmaceuticals, confectionary, oral hygiene products, pesticides, cosmetics, and as a flavoring agent. In addition, menthol is known to have antioxidant, anti-inflammatory, and analgesic effects. Recently, there has been renewed awareness in comprehending the biological and pharmacological effects of menthol. TRP channels have been demonstrated to mediate the cooling actions ofmenthol. There has been new evidence demonstrating thatmenthol can significantly influence the functional characteristics of a number of different kinds of ligand and voltage-gated ion channels, indicating that at …

Life Behind The Wall: Sensing Mechanical Cues In Plants, Olivier Hamant, Elizabeth S. Haswell

Biology Faculty Research

There is increasing evidence that all cells sense mechanical forces in order to perform their functions. In animals, mechanotransduction has been studied during the establishment of cell polarity, fate, and division in single cells, and increasingly is studied in the context of a multicellular tissue. What about plant systems? Our goal in this review is to summarize what is known about the perception of mechanical cues in plants, and to provide a brief comparison with animals.

Effect Assessment Of Tio2 Nanoparticles Exposure On Medicago By Monitoring Morphophysiology, Charles Towey

Mahurin Honors College Capstone Experience/Thesis Projects

In recent years titanium dioxide nanoparticles (TiO₂NPs) have been ingredients in everything from paints to cosmetics, and even in some kinds of food. This growth in use has resulted in a substantial increase in the amount of titanium released into the environment, which could have detrimental effects on nearby plant and animal life. Currently, the number of studies conducted on the effects of TiO₂NPs is quite small, especially when it comes to edible crops. Because of this lack of research data, this study has been designed to assess the effect of TiO₂ NPs exposure on …

The Interacting Roles Of Climate, Soils, And Plant Production On Soil Microbial Communities At A Continental Scale, M. P. Waldrop, J. M. Holloway, D. B. Smith, M. B. Goldhaber, Rebecca E. Drenovsky, K. M. Scow, R. Dick, D. Howard, B. Wylie, J. B. Grace

2017 Faculty Bibliography

Soil microbial communities control critical ecosystem processes such as decomposition, nutrient cycling, and soil organic matter formation. Continental scale patterns in the composition and functioning of microbial communities are related to climatic, biotic, and edaphic factors such as temperature and precipitation, plant community composition, and soil carbon, nitrogen, and pH. Although these relationships have been well explored individually, the examination of the factors that may act directly on microbial communities vs. those that may act indirectly through other ecosystem properties has not been well developed. To further such understanding, we utilized structural equation modeling (SEM) to evaluate a set of …

Effects Of Mycorrhizal Fungi On Vigna Radiata Growth In Soil Differing In Fertilizer Concentration, Ming Sum Jessica Cheng

Pursuit - The Journal of Undergraduate Research at The University of Tennessee

Mycorrhizal fungi form mutualistic relationships with the roots of some plants, allowing the plant access to nutrients and minerals while the fungi obtain food from the plant. Given that this relationship is beneficial to the plant, this paper investigates the nature of the impact of presence of mycorrhizal fungi on the growth of Vigna radiata (mung beans) in soil of differing chemical environments. Through comparing the stem lengths of plants seven days after germination, it is found that in soil with 0.0% fertilizer, the presence of locally collected, unclassified mycorrhizal fungi impacts the growth of Vigna radiata negatively; in intermediate …

The Population Genetics Of Morro Bay Eelgrass (Zostera Marina), Julia Gardner Harencar

Master's Theses

Seagrass populations are in decline worldwide. Zostera marina (eelgrass), one of California’s native seagrasses, is no exception to this trend. In the last 8 years, Morro Bay, California has lost 95% of its eelgrass. Eelgrass is an ecosystem engineer, providing important ecosystem services such as sediment stabilization, nutrient cycling, and nursery habitats for fish. The failure of recent restoration efforts necessitates a better understanding of the causes of eelgrass decline in this estuary. Previous research on eelgrass in California has demonstrated a link between population genetic diversity and eelgrass bed health, ecosystem functioning, and resilience to disturbance and extreme climatic …

Differentiating The Neches River Rose Mallow (Hibiscus Dasycalyx) From Its Congeners By Means Of Phylogenetics And Population Genetics, Julia Norrell

Biology Theses

This study used molecular phylogenetic methods to attempt to resolve the taxonomic status of the federally threatened East Texas-endemic wildflower, the Neches River Rose Mallow (Hibiscus dasycalyx). Hibiscus dasycalyx co-occurs with two other closely related congeners that are currently not of conservation concern: the halberdleaf rose mallow (H. laevis); and the crimson-eyed rose mallow (H. moscheutos). This study assessed the phylogeny of these three Hibiscus species, and attempted to determine if there is possible hybridization occurring between them. To this end, Restriction Site Associated DNA Sequencing (RAD-Seq), a Next Generation Sequencing method, was used …

Vegetative Rapid Assessment And Habitat Quality Analysis Of Steidtmann Woods, Sarah Mae Bail

Honors Projects

Due to invasive species and the assumption of an unhealthy ecosystem, Steidtmann Woods is an underutilized piece of land owned by Bowling Green State University. However, the property had never been analyzed. The proposed hypothesis was that Steidtmann was indeed in destress and its ecosystem could benefit from intervention—removal of invasive species and supplementation of natives. Through a rapid vegetative analysis, data was collected in several regions of the woods to identify what navies and non-natives were present as well as to identify their proportions. With that data, the species evenness, richness, and diversity was calculated; first, with raw field …

Range-Wide Prevalence And Impacts Of Pseudocercosporella Inconspicua On Lilium Grayi And An Assessment Of L. Superbum And L. Michauxii As Reservoirs, Cindy L. Barrett

Electronic Theses and Dissertations

Lilium grayi (Gray’s Lily), a southern Appalachian endemic species, is threatened by a Lilium-specific fungal pathogen, Pseudocercosporella inconspicua. The disease is characterized by tan lesions that can cause early senescence, while also lowering seed production and viability. This project tested for P. inconspicua conidia and accessed health at nine locations. The disease was present and ubiquitous across the range of L. grayi. Through identification of P. inconspicua conidia in the field, L. superbum (Turk’s Cap Lily) was identified as an additional host, while L. michauxii (Michaux’s Lily) was disease-free. However, infection was inducible in both species. With …

Abiotic Conditions Of Rare Pitcher's Thistle Attract Selection By An Invasive Weevil, Monica Paniagua Montoya

Lawrence University Honors Projects

Plant associations occur when host selection of a focal plant is reduced or increased by the presence of another plant species. Larinus planus is an invasive weevil whose larvae feed in the flower heads of native and federally threatened Pitcher’s thistle (Cirsium pitcheri). Studies have linked the presence of neighboring plants to increased host selection of Pitcher’s thistle by the weevil, but the factors contributing to host selection remain unknown. In our study, we determined if there were differences among abiotic factors, host selection and weevil behavior at Pitcher’s thistles surrounded by beach grass, sand and at high …

The Arabidopsis Kinesin-4, Fra1, Requires A High Level Of Processive Motility To Function Correctly, Anindya Ganguly, Logan Demott, Ram Dixit

Biology Faculty Research

Processivity is important for kinesins that mediate intracellular transport. Structure–function analyses of N-terminal kinesins (i.e. kinesins comprising their motor domains at the N-terminus) have identified several non-motor regions that affect processivity in vitro. However, whether these structural elements affect kinesin processivity and function in vivo is not known. Here, we used an Arabidopsis thaliana kinesin-4, called Fragile Fiber 1 (FRA1, also known as KIN4A), which is thought to mediate vesicle transport, to test whether mutations that alter processivity in vitro lead to similar changes in behavior in vivo and whether processivity is important for the function of FRA1. We …

Hydraulic Mechanisms Of Fungal-Induced Dieback In A Keystone Chaparral Species During Unprecedented Drought In California, Natalie M. Aguirre, Marissa E. Ochoa, Helen I. Holmlund, Frank E. Ewers, Stephen D. Davis

Seaver College Research And Scholarly Achievement Symposium

Between 2012-2016, southern California experienced unprecedented drought that caused dieback in Malosma laurina, a keystone species of chaparral shrub communities. Dieback was especially severe in coastal exposures of the Santa Monica Mountains, leading to whole plant mortality exceeding 50% at some sites. We hypothesized that the endophytic fungus causing the dieback, Botryosphaeria dothidea, was successful in invading the xylem tissue of M. laurina because of protracted water stress, carbon starvation, or a combination of the two. We tested these possibilities in a controlled pot experiment by comparing three treatments, each inoculated with the fungus: (1) irrigated controls (2) …

Small Scale Heterogeneity In Vegetation Structure In A Patch-Burn-Grazing Landscape, Eric G. Behrens

UNO Student Research and Creative Activity Fair

Disturbances are drivers of spatial change in the plant communities of the tallgrass prairie ecosystem. Fire and large herbivore grazing are prevalent disturbances that maintain the vegetation structure and create spatial heterogeneity in vegetation at various scales. The fire-grazing disturbance interaction occurs when areas that have been recently burned are followed by intense grazing due to the high quality of forage regrowth. This interaction has been managed in tallgrass prairies in a homogenous method using uniform burning and grazing and a heterogeneous method using patch-burn-grazing (PBG). Vegetation heterogeneity at a large scale has been studied in PBG and uniformly managed …

Invasive Species Control And Perennial Plant Establishment In Antelope Pasture, Pocatello, Blm, Kari E. Veblen

Funded Research Records

No abstract provided.

An On-Campus Botanical Tour To Promote Student Satisfaction And Learning In A University Level Biodiversity Or General Biology Course, Harish H. Ratnayaka

Faculty and Staff Publications

Outdoor, hands-on and experiential learning, as opposed to instruction-based learning in classroom, increases student satisfaction and motivation leading to a deeper understanding of the subject. However, the use of outdoor exercises in undergraduate biology courses is declining due to a variety of constraints. Thus, the goal of this paper is to describe a convenient, no-cost and flexible exercise using an on-campus botanical tour for strengthening specific knowledge areas of major plant groups. Its assessment on conduct and coverage, and student-perceived and actual knowledge gain is also described. Data presented derived from traditional biology undergraduates in sophomore year over nine fall …

A New Species Of Cyperus Section Incurvi (Cyperaceae) From Venezuela, Gordon Tucker

Faculty Research & Creative Activity

Cyperus fedoniae is described as a new species. It is known from a single collection from the lowlands of southern Venezuela. It is a member of section Incurvi. It is related to C. dichromeniformis and C. inops, from which it can be distinguished by its smaller size and features of spikelets and achenes. A distinctive feature is the arching culms which take root at the base of the spikelets.Cyperus fedoniae es descrito como una nueva especie. Se conoce de una sola muestra de las tierras bajas del sur de Venezuela. Es un miembro de la secci.n Incurvi. Est. relacionada con …