Physiology Commons^™

A Rapid Species-Specific Diagnostic Assay For Xylaria Necrophora, The Pathogen Behind Taproot Decline Of Soybean In The Southern United States, Sophie Baron Sheffield

Honors Capstones

No abstract provided.

The Role Of Nitric Oxide In Inter- And Intra- Cellular Signaling In Plant Defense, Fan Xia

Theses and Dissertations--Plant Pathology

Plants have evolved a sophisticated immune system to defend themselves against pathogens. This immune response can be triggered in response to pathogen-associated molecular patterns (PAMP) or specialized effectors that are recognized by the plant resistance (R) proteins. The latter, commonly referred to as effector-triggered immunity (ETI), is well known to induce broad-spectrum resistance throughout the plants. This phenomenon known as systemic acquired resistance (SAR) is regulated by several chemical signals including salicylic acid (SA), and free radical nitric oxide (NO) and reactive oxygen species (ROS). These signals operate in two parallel branches with NO/ROS functioning downstream of pipecolic acid (Pip) …

Common Garden Study Reveals Frost-Tolerant, Generalist Northern Seed Sources Are Best Suited To Expand Range Of Quercus Rubra, Emily Lindback

Dissertations, Master's Theses and Master's Reports

Climate change is shifting the potential suitable range of northern red oak (Quercus rubra L.) faster than it can migrate, creating an adaptation lag. Quercus rubra is prominent in eastern North American forests and important for its carbon sequestration, ecological roles, and economic significance. Our study addresses which populations of Q. rubra are best suited for climatic conditions at the northern and central range limits. Our findings can inform forestry management policies such as assisted migration, where species are transferred within their native range to mitigate the effects of climate change. We planted over 800 Q. rubra seedlings …

Temperature Regulation Of Plant Hormone Signaling During Stress And Development, Christian Castroverde, Damaris Dina

Biology Faculty Publications

Global climate change has broad-ranging impacts on the natural environment and human civilization. Increasing average temperatures along with more frequent heat waves collectively have negative effects on cultivated crops in agricultural sectors and wild species in natural ecosystems. These aberrantly hot temperatures, together with cold stress, represent major abiotic stresses to plants. Molecular and physiological responses to high and low temperatures are intricately linked to the regulation of important plant hormones. In this review, we shall highlight our current understanding of how changing temperatures regulate plant hormone pathways during immunity, stress responses and development. This article will present an overview …

Lighting The Way: Recent Insights Into The Structure And Regulation Of Phototropin Blue Light Receptors, Jaynee E. Hart, Kevin H. Gardner

Publications and Research

The phototropins (phots) are light-activated kinases that are critical for plant physiology and the many diverse optogenetic tools that they have inspired. Phototropins combine two bluelight- sensing Light–Oxygen–Voltage (LOV) domains (LOV1 and LOV2) and a C-terminal serine/threonine kinase domain, using the LOV domains to control the catalytic activity of the kinase. While much is known about the structure and photochemistry of the light-perceiving LOV domains, particularly in how activation of the LOV2 domain triggers the unfolding of alpha helices that communicate the light signal to the kinase domain, many questions about phot structure and mechanism remain. Recent studies have made …

Life Line March 2021, Otterbein Biology And Earth Science Department

Life Line - The Biology Department Newsletter

In this issue:

A Note from the Chair; The Department Welcomes Dr. Rich; Senior Research Symposium Goes Virtual; Three Department Faculty Members Win Teaching Awards; Svitana Helps NGWA Go Online; Carter '15 Earns Ph.D. in Nuclear Forensics; Revamping a Campus to Return to our Cardinal Community; Professor Uses Novel Teaching Practices During Pandemic; Otterbein Introduces Signature STEM Series to Increase Connection; Young Receives Career Award; Malacogy in a Time of COVID; COVID Conversations; Canine Rabies Vaccination in Ethiopia; The Cardinal Science Scholar Program; Bird Anatomy.

Investigation Of Salt Tolerance Mechanisms Across A Root Developmental Gradient In Almond Rootstocks, Yuhang Shao, Yukun Cheng, Hongguang Pang, Mingqin Chang, Fang He, Minmin Wang, Destiny J. Davis, Shuxiao Zhang, Oliver Betz, Chuck Fleck, Tingbo Dai, Shahab Madahhosseini, Thomas E. Wilkop, Judy Jernstedt, Georgia Drakakaki

Physiology Faculty Publications

The intensive use of groundwater in agriculture under the current climate conditions leads to acceleration of soil salinization. Given that almond is a salt-sensitive crop, selection of salt-tolerant rootstocks can help maintain productivity under salinity stress. Selection for tolerant rootstocks at an early growth stage can reduce the investment of time and resources. However, salinity-sensitive markers and salinity tolerance mechanisms of almond species to assist this selection process are largely unknown. We established a microscopy-based approach to investigate mechanisms of stress tolerance in and identified cellular, root anatomical, and molecular traits associated with rootstocks exhibiting salt tolerance. We characterized three …

Genetics Of Physiological Traits Associated With Drought Tolerance In Soybean (Glycine Max), Sumandeep Kaur Bazzer

Graduate Theses and Dissertations

Soybean (Glycine max L.) is one of the major row crops in the United States, and its production is often limited by drought stress. Physiological traits from exotic germplasm that confer drought tolerance may be useful in improving commercial soybean production. For example, carbon isotope ratio (δ13C) is positively correlated with water use efficiency (WUE), and nitrogen isotope ratio (δ15N) is negatively correlated with N2 fixation; canopy temperature (CT) is an indicator for genetic variation in transpiration and stomatal conductance. Therefore, the objectives of this research were to identify the genomic regions associated with: (1) δ13C and δ15N using a …

Characterizing The Role Of Β-Amylase3 In Cold Stress Response And Recovery In Arabidopsis Thaliana, Isabelle G. Houston

Senior Honors Projects, 2020-current

Starch is a polymer of glucose that is used as an energy store in plants. Mobilization of starch has implications in abiotic stress survival and recovery. While the importance of carbon and energy allocation in plant survival has been explored, the specific roles of starch degrading enzymes in plant responses to stress are still unclear. β-Amylase3, or BAM3, is the principle starch degrading enzyme at night and is transcriptionally upregulated in response to cold stress in the plant Arabidopsis thaliana. Using single and quadruple knockout mutant plants, I aimed to clarify the role of BAM3 in the response to …

Expression Profiling And Mutant Analysis Reveal Complex Regulatory Networks Involved In Arabidopsis Response To Biotic, Abiotic And Hormonal Stresses, Arjun Sham Valiyaveettil Shamgopal

Biology Dissertations

Biotic and abiotic stress factors consistently threat during different stages of the plant’s life cycle. A complex network of signaling molecules is required to overcome stresses, which is linked to general physiological and molecular processes. Botrytis cinerea is a necrotrophic fungal pathogen that causes grey mold disease on many crops. Apart from B. cinerea, several biotic, abiotic and hormonal stresses have detrimental effects on plant growth and productivity. The aim of this study is to identify the genetic regulations of individual stress types using comparative microarray analyses, and to find out the role of differentially expressed genes in Arabidopsis- …

Life Line March 2020, Otterbein Biology And Earth Science Department

Life Line - The Biology Department Newsletter

The Department Welcomes Dr. Sinn; Modeling to Help with Global Research; The Paradise of Bombs Revisited; The End of an Era in Conesville Ohio; Reports from two recipients of the Melinda Phinney Award for Pre-Med Travel Experiences; Preparing Skins for Study; Genomics in the Jungle; Zoo Program Gets New T -Shirt and Sweatshirt Designs; Aquarium Track Dives Right In; Dr. Svitana’s Sabbatical Accomplishments;Biology Behind Bars; Grossology: The Science of Icky, Sticky, Disgusting Things.

Greening Rates And Photosynthetic Development Of Leaves In C3 And C4 Plants, Tayler J. Kriss

Master's Theses or Doctor of Nursing Practice

To study chlorophyll development time and overall photosynthetic development in C3 and C4 leaves, seeds were germinated in complete darkness and achlorophyllous leaves were then allowed to develop in lighted conditions. Corn (Zea mays, C4), sorghum (Sorghum bicolor, C4), green bean (Phaseolus vulgaris, C3), broad bean (Vicia faba, C3), and wheat (Triticum aestivum, C3) were investigated for the first ten days of sunlight exposure. Chlorophyll concentration, chlorophyll fluorescence, and CO2 gas exchange measurements were conducted daily on the first leaf that emerged after the embryonic leaves of each plant. The first five days of the experiment, days zero to four …

Effects Of Abiotic Stresses On Sorbitol And Ribitol Accumulation And Sorbitol Biosynthesis And Metabolism In Tomato [Solanum Lycopersicum L.], Afaf Almaghamsi

Theses and Dissertations--Plant and Soil Sciences

Abiotic stresses are responsible for limiting crop production worldwide. Among diverse abiotic stresses, drought and salinity are the most challenging. Plants under these conditions have diverse strategies for tolerating stress. Osmotic adjustment and osmoprotection occur in plants during salinity and drought stress through accumulation of compatible solutes to a high level without interfering with cellular metabolism. Polyols (sugar alcohols) including sorbitol and ribitol are one such class of compatible solutes. Using plants of wild-type (WT) and three genetically-modified lines of tomato (Solanum lycopersicum cv. ‘Ailsa Craig’), an empty vector line ‘TR22’, and 2 sdh anti-sense lines ‘TR45’, and ‘TR49’ …

Quantifying The Morphological And Physiological Effects Of Drought, Grass Invasion, And Fire On Longleaf, Loblolly, And Slash Pine, Laura Young

College of Graduate Studies: Theses & Dissertations

Climate change is altering ecosystems on a global scale, creating novel ecological scenarios with which plant species must cope. Factors such as altered precipitation and fire regimes and non-native plant invasion may negatively affect native plant species, while interactions between these stressors could magnify their impacts. The complexity of multiple stressors and the effects they have on native pine seedlings are difficult to predict without evaluating their combinations in field experiments. In a multi-year study, I investigated the effects of drought and plant invasion on three southeastern pine species under pre and post-fire conditions. We planted longleaf (Pinus palustris …

Grapevine Vein Clearing Virus: Epidemiological Patterns And Construction Of A Clone, Cory Von Keith

Graduate Theses/Dissertations

Grapevine vein clearing virus (GVCV) is a recently discovered virus belonging to the Badnavirus genus. Characteristic to its name, the virus is associated with a disease where symptoms manifest as pronounced vein-clearing, resulting in severe berry deformation and vine decline in susceptible grape varieties. Sustainable production of wine is dependent on healthy plants. The associated disease is mainly found in Midwest vineyards. Attempts were made in this thesis to provide evidence of causality of the virus to the associated disease and to infer the historical path and migration pattern of GVCV. Conclusions and discussions will provide grape producers with the …

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 …

Searching For Potential Binding Partners Of Arabidopsis Β-Amylase9 Using Yeast 2-Hybridization, Sheikh Hossain

Senior Honors Projects, 2010-2019

In plants, starch is a major carbon and energy storage compound. Starch is made as a product of photosynthesis while plants are in light and is degraded at night. Our lab is interested in the cellular mechanism of starch degradation in plants and for our studies we use Arabidopsis thaliana as a model. β-amylases are primarily responsible for the hydrolysis of starch in plants and a total of nine β-amylases genes are encoded in Arabidopsis thaliana. These nine genes are identified as BAM1-9. BAM9 is located in the chloroplast where starch is located, and is present …

Factors Influencing Induction Of Desiccation Tolerance In Bryophytes: Redefining Fundamental Aspects Of The Organism’S Relationship With The Environment In Xeric Habitats, Joshua Lee Greenwood

UNLV Theses, Dissertations, Professional Papers, and Capstones

If one wishes to understand the ecological role, range, habitat preferences, selective pressures, reproduction, response to climate change, and the potential for survival under climactic change, range expansion and range contraction for species and populations of bryophytes, an understanding of their survival of the desiccated state, is essential. In order to further our understanding of desiccation tolerance in mosses, three projects were undertaken. The first of these investigated the nature of desiccation tolerance in mosses, specifically if desiccation tolerance can be induced; thereby providing a desiccation tolerant phenotype in a moss species generally considered desiccation sensitive (Physcomitrella patens, the model …

Odor, Not Performance, Dictates Bemisia Tabaci'S Selection Between Healthy And Virus Infected Plants, Gong Chen, Qi Su, Xiaobin Shi, Xin Liu, Zhengke Peng, Huixin Zheng, Wen Xie, Baoyun Xu, Shaoli Wang, Qingjun Wu, Xuguo Zhou, Youjun Zhang

Entomology Faculty Publications

Although, insect herbivores are generally thought to select hosts that favor the fitness of their progeny, this “mother-knows-best” hypothesis may be challenged by the presence of a plant virus. Our previous study showed that the whitefly, Bemisia tabaci, the obligate vector for transmitting Tomato yellow leaf curl virus (TYLCV), preferred to settle and oviposit on TYLCV-infected rather than healthy host plant, Datura stramonium. The performances of B. tabaci larvae and adults were indeed improved on virus-infected D. stramonium, which is consistent with “mother-knows-best” hypothesis. In this study, B. tabaci Q displayed the same preference to settle and …

Development Of Near-Isogenic Lines In A Parthenogenetically Reproduced Thrips Species, Frankliniella Occidentalis, Guangdi Yuan, Yanran Wan, Xiaoyu Li, Bingqing He, Youjun Zhang, Baoyun Xu, Shaoli Wang, Wen Xie, Xuguo Zhou, Qingjun Wu

Entomology Faculty Publications

Although near-isogenic lines (NILs) can standardize genetic backgrounds among individuals, it has never been applied in parthenogenetically reproduced animals. Here, through multiple rounds of backcrossing and spinosad screening, we generated spinosad resistant NILs in the western flower thrips, Frankliniella occidentalis (Pergande) (Thysanoptera: Thripidae), with a haplo-diploid reproduction system. The resultant F. occidentalis NIL-R strain maintained a resistance ratio over 30,000-fold, which was comparable to its parental resistant strain, Spin-R. More importantly, F. occidentalis NIL-R shared 98.90% genetic similarity with its susceptible parental strain Ivf03. By developing this toolset, we are able to segregate individual resistance and facilitate the mechanistic study …

Araucaria In The Urban Landscape: A Novel Leaning Pattern And Evidence Of Cultivated Hybridization, Jason W. Johns

Master's Theses

Our understanding of the natural world is constantly evolving and strengthening as more observations are made and experiments are performed. For example, we understand that tree stems grow toward the light (positive phototropism; Darwin 1880, Loehle 1986, Christie et al. 2013) and against gravity (negative gravitropism; Knight 1806, Hashiguchi et al. 2013). We also know that plants respond to mechanical stimulus and perturbation (thigmotropism; Braam 2005). Genes and their resulting proteins have been described to uncover some of the mechanisms for these environmental responses, but relatively speaking, we have just scratched the surface (Wyatt et al. 2013). While the discovery …

Transcriptional And Post-Translational Regulation Of Terpenoid Indole Alkaloid Biosynthesis In Catharanthus Roseus, Priyanka Paul

Theses and Dissertations--Plant and Soil Sciences

Catharanthus roseus (Madagascar periwinkle) is the exclusive source of an array of terpenoid indole alkaloids (TIAs) that are used in the treatments of hypertension and certain types of cancer. TIA biosynthesis is under stringent spatiotemporal control and is induced by jasmonate (JA) and fungal elicitors. Tryptamine, derived from the indole branch, and secologanin from the iridoid branch are condensed to form the first TIA, strictosidine. Biosynthesis of TIA is regulated at the transcriptional level and several transcription factors (TFs) regulating the expression of genes encoding key enzymes in the pathway have been isolated and characterized. The JA-responsive APETALA2/ETHYLENE RESPONSE FACTOR …

Using Exogenous Hormone Application To Suppress Axillary Shoot Development In Tobacco, W. Jesse Carmack

Theses and Dissertations--Plant and Soil Sciences

The variability in the number of basal axillary shoots (ground suckers) among all tobacco (Nicotiana tabacum L.) varieties, has increased since the hydroponic transplant production system became the standard. The larger root ball of hydroponically produced transplants compared to traditionally produced transplants potentially generates a difference in the ratio of auxin (inhibits axillary shoot formation) to cytokinin (promotes lateral branching), that induces basal axillary shoot development. Starting in 2014, studies were conducted to investigate whether the addition of synthetic auxins or cytokinins to hydroponic transplant production could prevent ground sucker formation. Different tobacco cultivars, with high or low ground sucker …

Influence Of Topography And Moisture And Nutrient Availability On Green Alder Function On The Low Arctic Tundra, Nt, Katherine Louise Black Ms., Jennifer Lynn Baltzer Dr.

Theses and Dissertations (Comprehensive)

The Arctic has warmed by at least 3^°C over the past 50 years and this rapid warming is expected to continue. Climate warming is driving the proliferation of shrubs across the tundra biome with implications for energy balance, climate, hydrology, nutrient cycling, and biodiversity. Changes in tundra plant water use attributable to shrub expansion are predicted to increase evapotranspirative water loss which may amplify local warming and reduce run-off. However, little is known about the extent to which shrubs will enhance evapotranspirative water loss in these systems. Direct measures of shrub water use are needed to accurately predict …

Impacts Of Long-Term Precipitation Manipulation On Hydraulic Architecture, Xylem Function, And Canopy Status In A Piñon-Juniper Woodland, Patrick J. Hudson

Biology ETDs

The Southwestern US is predicted to become hotter and drier, as global climate change forces increasing temperatures and variability in timing and size of precipitation inputs. Drought stress has become more frequent in recent decades, and resulted in massive forest mortality in piñon-juniper woodlands. During recent severe droughts (2000-2003, 2009-2012), piñon pine (Pinus edulis Englem.) suffered disproportionately high mortality compared to co-occurring one-seed juniper (Juniperus monosperma [Engelm.] Sarg.). A large-scale precipitation manipulation experiment was established in a piñon-juniper woodland in central New Mexico to test hypotheses regarding tree survival and mortality with respect to altered water regimes. Our …

Nuclear Factor [Erythroid-Derived 2]-Like 2’S (Nfe2l2) Gene Expression In Feed Efficiency And Oxidative Stress In Avian Muscle, Devin Wayne Cook

Graduate Theses and Dissertations

Oxidative stress may play a role in the phenotypic expression of feed efficiency (FE). The transcription factor NFE2L2 (nuclear factor erythroid-derived 2-like 2) coordinates antioxidant response to oxidative stress and its activity is tightly regulated in part by KEAP1 (Kelch like-ECH protein 1) and the E3 ligase CUL3 (Cullin3). Thus, one objective was to determine mRNA expression of NFE2L2, KEAP1, and CUL3 as well as three antioxidant targets [glutathione peroxidase (GPx-1), superoxide dismutase 1 (SOD1), and superoxide dismutase 2 (SOD2)] in breast muscle of immature pedigree broiler males (8 wk), immature Japanese quail males (4 wk) divergently selected for high …

Growth And Productivity Of Irrigated Rice (Oryza Sativa L.) For A Tropical High Altitude Environment In Rwanda, Elie Rene Gasore

Graduate Theses and Dissertations

Yield components, grain yield, biomass and plant N accumulation, and N fertilizer responses of irrigated rice (Oryza sativa, L.) were evaluated for a tropical inland valley environment in the high altitudes in Rwanda. Effects were measured for nitrogen (N) fertilizer rate (0, 60, 90,120,150,180 kg N ha-1), season, growth stage and cultivar of different subspecies and plant types during 2012 dry season (DS) and 2013 wet season (WS) at Cyili Rice Research Farm (1380 m above sea level). Variations in irradiance (17.2± 0.32 MJ m-2 day-1 in DS and 9.4 ± 0.66 MJ m-2 day-1in WS) were linked to seasonal …

Using Detection Dogs And Rspf Models To Assess Habitat Suitability For Bears In Greater Yellowstone, Jon P. Beckmann, Lisette P. Waits, Aimee Hurt, Alice Whitelaw, Scott Bergen

Western North American Naturalist

In the northern U.S. Rockies, including the Greater Yellowstone Ecosystem (GYE), connectivity is a concern because large carnivores have difficulties dispersing successfully between protected areas. One area of high conservation value because of its importance for connecting the GYE to wilderness areas of central Idaho is the Centennial Mountains and surrounding valleys (2500 km2) along the Idaho–Montana border just west of Yellowstone National Park. The current expansion of grizzly bears (Ursus arctos) and other large carnivore populations outside protected areas of Yellowstone National Park and Grand Teton National Park has placed a greater emphasis on potential linkage zones …

Expressing And Characterizing Mechanosensitive Channels In Xenopus Oocytes, Grigory Maksaev, Elizabeth S. Haswell

Biology Faculty Research

The oocytes of the African clawed frog (Xenopus laevis) comprise one of the most widely used membrane protein expression systems. While frequently used for studies of transporters and ion channels, the application of this system to the study of mechanosensitive ion channels has been overlooked, perhaps due to a relative abundance of native expression systems. Recent advances, however, have illustrated the advantages of the oocyte system for studying plant and bacterial mechanosensitive channels. Here we describe in detail the methods used for heterologous expression and characterization of bacterial and plant mechanosensitive channels in Xenopus oocytes.

Trip: Tracking Rhythms In Plants, An Automated Leaf Movement Analysis Program For Circadian Period Estimation, Kathleen Greenham, Ping Lou, Sara E. Remsen, Hany Farid, C Robertson Mcclung

Dartmouth Scholarship

Background: A well characterized output of the circadian clock in plants is the daily rhythmic movement of leaves. This process has been used extensively in Arabidopsis to estimate circadian period in natural accessions as well as mutants with known defects in circadian clock function. Current methods for estimating circadian period by leaf movement involve manual steps throughout the analysis and are often limited to analyzing one leaf or cotyledon at a time.

Methods: In this study, we describe the development of TRiP (Tracking Rhythms in Plants), a new method for estimating circadian period using a motion estimation algorithm that can …