Life Sciences Commons^™

Integration Of Developmental And Environmental Signals Via A Polyadenylation Factor In Arabidopsis, Man Liu, Ruqiang Xu, Carrie Merrill, Liwei Hong, Carol Von Lanken, Arthur G. Hunt, Qingshun Q. Li

Plant and Soil Sciences Faculty Publications

The ability to integrate environmental and developmental signals with physiological responses is critical for plant survival. How this integration is done, particularly through posttranscriptional control of gene expression, is poorly understood. Previously, it was found that the 30 kD subunit of Arabidopsis cleavage and polyadenylation specificity factor (AtCPSF30) is a calmodulin-regulated RNA-binding protein. Here we demonstrated that mutant plants (oxt6) deficient in AtCPSF30 possess a novel range of phenotypes--reduced fertility, reduced lateral root formation, and altered sensitivities to oxidative stress and a number of plant hormones (auxin, cytokinin, gibberellic acid, and ACC). While the wild-type AtCPSF30 (C30G) was …

Using Plant Volatile Traps To Develop Phenology Models For Natural Enemies: An Example Using Chrysopa Nigricornis (Burmeister) (Neuroptera: Chrysopidae), Vincent P. Jones, David R. Horton, Nicholas J. Mills, Thomas R. Unruh, Eugene R. Milickzy, Peter W. Shearer, Kaushalya G. Amarasekare, Callie C. Baker, Tawnee D. Melton

Agricultural and Environmental Sciences Faculty Research

A model predicting phenology of adult Chrysopa nigricornis (Burmeister) (Neuroptera: Chrysopidae) in orchards was developed from field (trapping) data supplemented with development data collected under laboratory conditions. Lower and upper thresholds of 10.1°C and 29.9°C, respectively, were estimated from published and unpublished laboratory observations, and were used to develop a phenology model. Season-long field data were collected using white delta traps that had been baited with squalene, a volatile shown previously to be highly attractive to C. nigricornis. The model was developed from data collected in three Washington apple orchards, and was validated using independent data sets collected from apple, …

Interplanting Annual Ryegrass, Wheat, Oat, And Corn To Mitigate Iron Deficiency In Dry Beans, Emmanuel Chiwo Omondi, Andrew R. Kniss

Agricultural and Environmental Sciences Faculty Research

This study evaluated whether grass intercropping can be used to alleviate Fe deficiency chlorosis in dry beans (Phaseolus vulgaris L.) grown in high pH, calcareous soils with low organic matter. Field studies were conducted at the University of Wyoming Sustainable Agriculture Research and Extension Center in 2009 and 2010. Black- and navy beans were grown alone or intercropped with annual ryegrass (Lolium multiflorum Lam.), oat (Avena sativa L.), corn (Zea mays L.), or spring wheat (Triticum aestivum L.) in a two-factor factorial strip-plot randomized complete block design. All four grass species increased chlorophyll intensity in dry beans. However, grass species …

Changes In Corn Residue Quality Throughout The Grazing Period And Effect Of Supplementation Of Calves Grazing Corn Residue, Amanda J. Burken

Department of Animal Science: Dissertations, Theses, and Student Research

Corn residue is an abundant feed source in Nebraska that can be utilized as an alternative winter feed. Calves were backgrounded on corn residue in order to determine gain and estimate forage intake when supplemented with distillers grains (DGS). Calves grazing the non-irrigated field gained more (1.03 kg/calf daily) when compared to those grazing the irrigated field (0.90 kg/calf daily; P < 0.01). In year 1, a quadratic effect for intake of DGS was present (P < 0.01) while year 2 observed a linear effect for increasing level of DGS (P < 0.01). The nutritional quality of corn residue was evaluated over time in order to determine changes in blade/sheath, cob, husk/shank and stem. Minimal changes in DM of the forage components occurred was grain reached 15.5% moisture. Digestibility of the blade/sheath declined linearly over time (P < 0.01) while the husk remained constant (P = 0.40). Cob digestibility decreased quadratically (P < 0.01) throughout the sampling period with few changes once grain reached 15.5% moisture. Differences observed in the digestibility of the blade/sheath were attributed to the effects of weathering. A third set of trials was conducted to evaluate the effects of by-product supplementation of calves grazing irrigated corn residue and supplemented with DGS or continuous access to lick tubs. The DGS treatment gained more (0.62 kg/calf daily) than the lick tub treatment (0.38 kg/calf daily; P < 0.01). Calves offered DGS consumed more supplement as a percentage of BW (0.52%) when compared with calves offered lick tubs (0.36%; P < 0.01) on a DM basis. Calves supplemented with DGS had a higher supplement efficiency (46.3% to 42.9%, DM basis) although no differences were present between treatments (P = 0.49). When analyzed on an OM basis, however, calves offered lick tubs had a numerically higher supplement efficiency (50.4%) in comparison to calves …

Registration Of ‘Newell’ Smooth Bromegrass, K P. Vogel, R B. Mitchell, B L. Waldron, M R. Haferkamp, J D. Berdahl, D D. Baltensperger, Galen Erickson, T J. Klopfenstein

Green Canyon Environmental Research Area, Logan Utah

No abstract provided.

Managing Threats To The Urban Forest: From Dutch Elm Disease To Emerald Ash Borer - Learning From Experience, Christopher J. Borman

Doctor of Plant Health Program: Dissertations and Student Research

The urban forest provides important essential services to all municipalities; however, its value is often overlooked. The urban forest contributes to energy savings, environmental benefits, psychological well-being, and social benefits. Managing the urban forest in a sustainable manner is important if we wish to benefit from these services well into the future. Reliable management techniques have been created through previous experiences with pests, and these should be utilized and improved for use on urban forests.

American elm (Ulmus americana L.) was once a major component of the urban forests of North America. In 1927, Dutch elm disease (DED) was …

Soil Carbon And Nitrogen Mineralization And Crop Parameters In Typical Maize-Bean Intercropping In Western Kenya, Judith A. Odhiambo, Urszula Norton, Emmanuel C. Omondi, Dennis Ashilenje, Jay B. Norton

Agricultural and Environmental Sciences Faculty Research

Smallholder farmers in western Kenya who plant maize (Zea mays L.) intercropped with beans (Phaseolus vulgaris L.) face many challenges associated with nutrient-poor soils and weather-related crop failures. In regions where temperatures are favorable, crops are grown twice per year during long and short rainy seasons and in other regions, once per year during one long growing season. Growing crops two times per year necessitates frequent land preparation using inversion-type tillage. Little is known about the impact of current tillage-intensive crop management on annual soil organic matter (SOM) recovery. The aim of this study was to assess changes to soil …

Primulaceae, Jon M. Ricketson, John J. Pipoly Iii, B. Stahl, M. Moraes

Marine & Environmental Sciences Faculty Books and Book Chapters

No abstract provided.

Conservation Agriculture And Household Wellbeing: A Non-Causal Comparison Among Smallholder Farmers In Mozambique, W. E. Mcnair, Dayton Mcgregor Lambert, Neal S. Eash

Biosystems Engineering and Soil Science Publications and Other Works

This research examines the relationship between household wellbeing and the use of conservation agriculture (CA) by smallholder farmers in Mozambique. Wellbeing indicators are regressed on household demographic attributes, farm management practices, and a variable indicating farmer adoption of CA. Findings suggest that households using CA have higher wellbeing index scores related to farm tool and implement ownership and housing material quality, but lower index scores related to livestock ownership. The findings present an encouraging, baseline picture of the association between the use of CA technologies by farmers in Mozambique and household wellbeing.

Modeling Grain Yield And Straw Yield Of Wheat Using Back Propagation And Genetic Algorithm, Omar Maghawri Ibrahim Hassan Dr.

Dr. Omar Maghawri Ibrahim

The first objective of this study was to model the effect of yield components, number of grain/spike, number of spikes/m2, and 1000 kernels weight on the grain yield and straw yield of wheat. An artificial neural network (ANN), multilayer perceptron feed forward neural network (MLP) was used for developing the predictive model. Two different training algorithms: back propagation (BP) and genetic algorithm (GA) were used to train the MLP which structured of three neurons in the input layer, one hidden layer of six neurons, and two neurons in the output layer. The second objective of the current study was to …

The Relationship Between Riparian Zone Width And Floristic Quality In Shenandoah County, Virginia, Jamie D. Smith

Masters Theses, 2010-2019

Riparian zones harbor an above average plant biodiversity. This biodiversity is threatened by invasive species and increasing human disturbance, the latter of which includes deforestation from agriculture and urban development. In this study, I examine relationship between the width of a forested riparian zone and the vegetation growing there. By using floristic quality assessment as a measure of anthropogenic disturbance, one can determine if wider riparian zones foster exclusion of non-native species while providing higher quality habitats for native plants. A randomized block design was used with three forested riparian treatments: deforested, moderately forested (woody vegetationstream), and extensively forested (woody …

Potential Effects Of Elevated Co2 On Pitcher Plant Nectar Composition, Prey Capture, And Inquiline Communities, Deirdre Courtney

Honors Theses

Human activities such as fossil fuel burning and deforestation have contributed significantly to the increasing levels of CO₂ in the atmosphere since the industrial revolution. Under the IPCC A1FI emission scenario, we are expected to reach levels as high as 1000 ppm by the end of the century. On average, C₃ plants experience a 27% increase in carbon to nitrogen (C:N) ratio under elevated CO₂. As a result, C₃ plants typically exhibit an increase in carbon-based secondary compounds. Carnivorous plants are a rare type of C₃ plant that has adapted to survive in low …

Inheritance Of Virulence In The Root Rot Pathogen Phytophthora Sojae, Sirjana Devi Shrestha

Electronic Thesis and Dissertation Repository

The oomycete Phytophthora sojae causes stem and root rot of soybean plants. The interaction of pathogen avirulence (Avr) and host resistance (R)-genes determine the disease outcome. The Avr3a mRNA transcript level is variable among P. sojae strains and determines virulence towards the R-gene Rps3a. To study the inheritance of virulence, genetic crosses and self-fertilizations were performed. A cross between P. sojae strains ACR10 and P7076 causes transgenerational gene silencing of Avr3a allele, and this effect is meiotically stable up to the F₅ generation. However, test-crosses of F₁ (Avr3a^ACR10/Avr3a …

Mono- And Digalactosyldiacylglycerol Lipids Function Nonredundantly To Regulate Systemic Acquired Resistance In Plants, Qing-Ming Gao, Keshun Yu, Ye Xia, M. B. Shine, Caixia Wang, Duroy Navarre, Aardra Kachroo, Pradeep Kachroo

Plant Pathology Faculty Publications

The plant galactolipids monogalactosyldiacylglycerol (MGDG) and digalactosyldiacylglycerol (DGDG) have been linked to the anti-inflammatory and cancer benefits of a green leafy vegetable diet in humans due to their ability to regulate the levels of free radicals like nitric oxide (NO). Here, we show that DGDG contributes to plant NO as well as salicylic acid biosynthesis and is required for the induction of systemic acquired resistance (SAR). In contrast, MGDG regulates the biosynthesis of the SAR signals azelaic acid (AzA) and glycerol-3-phosphate (G3P) that function downstream of NO. Interestingly, DGDG is also required for AzA-induced SAR, but MGDG is not. Notably, …

Transceptors At The Boundary Of Nutrient Transporters And Receptors: A New Role For Arabidopsis Sultr1;2 In Sulfur Sensing, Zheng Zhiliang, Bo Zheng, Thomsa Leustek

Publications and Research

Plants have evolved a sophisticated mechanism to sense the extracellular sulfur (S) status so that sulfate transport and S assimilation/metabolism can be coordinated. Genetic, biochemical, and molecular studies in Arabidopsis over the past 10 years have started to shed some light on the regulatory mechanism of the S response. Key advances in transcriptional regulation (SLIM1, MYB, and miR395), involvement of hormones (auxin, cytokinin, and abscisic acid) and identification of putative sensors (OASTL and SULTR1;2) are highlighted here. Although our current view of S nutrient sensing and signaling remains fragmented, it is anticipated that through further studies a sensing and signaling …

Effect Of Photoperiod On Redox Regulation Of Phenotypic Plasticity And Cellular Growth In Chlorella Vulgaris, Lauren E. Hollis

Electronic Thesis and Dissertation Repository

Photoautotrophs are predisposed to maintain a balance between light energy absorption with the capacity to consume this energy through metabolism. An imbalance in energy flow may be a consequence of increased light intensity and is sensed as modulation of excitation pressure (EP). Chlorella vulgaris acclimated to continuous high EP exhibits a yellow-green phenotype characterized by reduced chlorophyll content and high chlorophyll a/b ratio with reduced light-harvesting complex abundance relative to the dark green phenotype of low EP-acclimated cultures. Previous studies on acclimation to EP in green algae have been conducted under constant growth light. To determine the role of EP …

Pseudomonas Syringae Type Iii Effectors: Targets And Roles In Plant Immunity, Tania Y. Toruño

Center for Plant Science Innovation: Faculty and Staff Publications

Pseudomonas syringae is a Gram-negative bacterial pathogen that infects many crops. A central virulence strategy P. syringae uses to successfully infect plants is the injection of type III effector proteins (T3Es) into plant cells through a type IIII protein secretion system (T3SS). The T3SS is a molecular syringe found in many Gram-negative bacterial pathogens of plants and animals that transport T3Es from the bacterial cytosol into eukaryotic cells. T3Es disrupt host processes in the plant immune system required to restrict pathogen ingress. The plant innate immune system is divided in two branches, pathogen-associated molecular patterns (PAMP)-triggered immunity (PTI) and effector-triggered …

Nitrous Oxide Emissions From A Commercial Cornfield (Zea Mays) Measured Using The Eddy Covariance Technique, H. Huang, J. Wang, D. Hui, D. R. Miller, S. Bhattarai, S. Dennis, D. Smart, T. Sammis, K. C. Reddy

Agricultural and Environmental Sciences Faculty Research

Increases in observed atmospheric concentrations of the long-lived greenhouse gas nitrous oxide (N2O) have been well documented. However, information on event-related instantaneous emissions during fertilizer applications is lacking. With the development of fast-response N2O analyzers, the eddy covariance (EC) technique can be used to gather instantaneous measurements of N2O concentrations to quantify the exchange of nitrogen between the soil and atmosphere. The objectives of this study were to evaluate the performance of a new EC system, to measure the N2O flux with the system, and finally to examine relationships of the N2O flux with soil temperature, soil moisture, precipitation, and …

Thylakoid Phosphorylation And Cell Morphology In The Antarctic Psychrophile, Chlamydomonas Sp. Uwo241, Beth Szyszka-Mroz

Electronic Thesis and Dissertation Repository

The unicellular green microalga, Chlamydomonas sp. UWO 241, was isolated from Lake Bonney, Antarctica. A unique characteristic of this algal strain is its inability to undergo state transitions combined with an altered thylakoid protein phosphorylation profile, which suggests the absence of LHCII phosphorylation, and preferential phosphorylation of a set of novel proteins. Examination of the unique phosphoproteins revealed that they are associated with a large pigment-protein supercomplex, which contains components of both photosystem I and the cytochrome b₆/f complex and likely functions in cyclic electron flow (CEF).

The absence of phosphorylation of LHCII proteins, associated with state …

Lingnan Gardeners Newsletter (No. 1) = 嶺南彩園通訊 (第1期), Lingnan Gardeners, Kwan Fong Cultural Research And Development Programme, Lingnan University

Lingnan Gardeners Newsletter 嶺南彩園通訊

No abstract provided.

Metabolic Engineering Of Oilseed Crops To Produce High Levels Of Novel Acetyl Glyceride Oils With Reduced Viscosity, Freezing Point And Calorific Value, Jinjie Liu, Adam Rice, Kathleen Mcglew, Vincent Shaw, Hyunwoo Park, Thomas E. Clemente, Mike Pollard, John Ohlrogge, Timothy P. Durrett

Department of Agronomy and Horticulture: Faculty Publications

Seed oils have proved recalcitrant to modification for the production of industrially useful lipids. Here, we demonstrate the successful metabolic engineering and subsequent field production of an oilseed crop with the highest accumulation of unusual oil achieved so far in transgenic plants. Previously, expression of the Euonymus alatus diacylglycerol acetyltransferase (EaDAcT) gene in wild-type Arabidopsis seeds resulted in the accumulation of 45 mol% of unusual 3-acetyl-1,2- diacyl-sn-glycerols (acetyl-TAGs) in the seed oil (Durrett et al., 2010 PNAS 107:9464). Expression of EaDAcT in dgat1 mutants compromised in their ability to synthesize regular triacylglycerols increased acetyl-TAGs to 65 mol%. Camelina and soybean …

Arabidopsis Chromatin Remodeler Brahma: Its Functional Interplay With Polycomb Proteins And The Ref6 Histone Demethylase, Chenlong Li

Electronic Thesis and Dissertation Repository

BRAHMA (BRM) is a SWI/SNF-type chromatin remodeling ATPase that plays an important role in regulation of gene expression. Tri-methylation of lysine 27 on histone H3 (H3K27me3) is a histone modification that is associated with transcriptionally repressed genes and catalyzed by Polycomb Group (PcG) proteins. BRM has been proposed to antagonize the function of PcG proteins but the underlying molecular mechanism is unclear. To understand how BRM regulates the function of PcG proteins during plant development, a genome-wide analysis of H3K27me3 in brm mutant was performed using chromatin immunoprecipitation followed by next generation sequencing (ChIP-seq). Loss of BRM leads to increased …

First Report Of Goss's Bacterial Leaf Blight And Wilt Of Corn Caused By Clavibacter Michiganensis Subsp. Nebraskensis In North Dakota, A. Friskop, K. Kinzer, M. Mcconnell, Z. Liu, K. A. Korus, A. Timmerman, T. Jackson

Department of Plant Pathology: Faculty Publications

In August of 2011, the North Dakota State University Plant Diagnostic Lab received a hybrid corn (Zea mays) leaf sample from Burleigh County in southcentral North Dakota (ND). The leaf had long, irregular, water-soaked lesions consistent with Goss's leaf blight of corn. Using a light microscope at 10× magnification, bacterial streaming was observed from the excised edge of leaf tissue. A bacterial suspension was created, streaked onto a semi-selective CNS medium (1), and incubated at 22°C. Dark yellow-orange colonies appeared on the medium after 5 days. Single colonies were subcultured onto additional CNS media. To verify the identity …

Decision Support Tools To Address Climate Change: Climate Model - Land Surface Models, Zea Mays L. (Corn) Phenology And Evapotranspiration-Yield Sensitivity Models For Nebraska, Usa., Jane A. Okalebo

School of Natural Resources: Dissertations, Theses, and Student Research

Nebraska's climate is highly variable and is expected to change in the future with anthropogenic global warming (AGW), resulting in warmer spring and summer temperatures coupled with more erratic rainfall events. This has strong implications for agriculture in the region, yet it is not clear that current modeling and decision-support tools are adequate to address these looming changes and provide planning, mitigation and adaptation strategies. To address climate change and its implications to agriculture in Nebraska, a set of robust decision support tools are very crucial. This study herein are divided into three chapters, with each chapter addressing a specific …

Assessing The Genetic Diversity Of The Genus Viburnum Using Simple Sequence Repeats, Deborah Dean

Doctoral Dissertations

The genus Viburnum was established in 1753 by Linnaeus and is the largest genus in the Adoxaceae and consists of approximately 160 species. Viburnum species are small trees which grow throughout the temperate regions of the Northern Hemisphere (Hoch, 1995). While this genus shares little variety in fruit and flower morphology, it is diverse in many other traits. As molecular studies advance, this large genus continues to undergo reclassification. Here three SSR libraries were constructed to discern additional molecular insight into this vast genus.

Microsatellite markers were developed to characterize Viburnum on several different levels. V. dilatatum is an introduced …

Pore Selectivity And Gating Of Arabidopsis Nodulin 26 Intrinsic Proteins And Roles In Boric Acid Transport In Reproductive Growth, Tian Li

Doctoral Dissertations

Plant nodulin-26 intrinsic proteins (NIPs) are members of the aquaporin superfamily that serve as multifunctional channels of uncharged metabolites and water. They share the same canonical hourglass fold as the aquaporin family. The aromatic arginine (ar/R) selectivity filter controls transport selectivity based on size, hydrophobicity, and hydrogen bonding with substrates. In Arabidopsis thaliana, NIP II subclass proteins contain a conserved ar/R “pore signature” that is composed of Alanine at the helix 2 position (H2), Valine/Isoleucine at the helix 5 position (H5), and an Alanine (LE1) and an invariant Arginine (LE2) at the two loop E positions. In this study, …

Evaluation Of Traits Associated With Breeding For Improved Biomass And Ethanol Yield In Switchgrass, Virginia Roseanna Sykes

Doctoral Dissertations

Switchgrass (Panicum virgatum L.) is a perennial, warm season grass that can be used as a biofuel. A greater understanding of the relationship of biomass yield and ethanol yield with disease susceptibility and morphological traits, estimation of the underlying genetic parameters of these traits, and the efficacy of selection at different maturity and under different production conditions could help breeders more effectively develop improved biofuel switchgrass cultivars. To examine these issues, three studies were performed. The first examined switchgrass leaves exhibiting low, medium, and high severity of rust symptoms, caused by infection with Puccinia emaculata. Results indicate P. …

Integration And Management Of Winter-Annual Cover Crops And Herbicides To Control Glyphosate-Resistant Palmer Amaranth (Amaranthus Palmeri S. Wats), Matthew Scott Wiggins

Doctoral Dissertations

The main objective of this research was to evaluate the integration of high residue winter-annual cover crops with herbicides, both preemergence and postemergence, to control glyphosate-resistant Palmer amaranth. The results of these trials indicated that winter-annual cover crops improved early-season weed suppression. However, cover crops alone or as part of an integrated weed management system including only preemergence or only postemergence herbicides was not sufficient to control of glyphosate-resistant Palmer amaranth. Therefore, winter-annual cover crops should be used in conjunction with existing weed control tactics to achieve adequate glyphosate-resistant Palmer amaranth control, where applicable.

Pacific Plug & Liner Crop Shrinkage Evaluation, Jillian Balli

Horticulture and Crop Science

Crop Shrinkage has a major impact on a company’s bottom line. There are many ways to combat shrinkage. This report focuses on shrinkage reduction by adjusting buffer planting numbers to reflect the actual number of plants lost in production. Inaccurate buffer can cause the cost of production to be inaccurate as well. This report evaluates crop shrinkage of a greenhouse located in Watsonville, CA called Pacific Plug & Liner.

Using Avifauna To Access The Functional Success Of The Restored Beaver Creek Wetlands Near Cave Run Lake, Menifee County, Kentucky, Brian D. Wulker

Morehead State Theses and Dissertations

A thesis presented to the faculty of the College of Science and Technology at Morehead State University in partial fulfillment of the requirements for the Degree of Master of Science in Biology by Brian D. Wulker on December 1, 2014.