Life Sciences Commons^™

Aquaporins Contribute To Aba-Triggered Stomatal Closure Through Ost1-Mediated Phosphorylation, Alexandre Grondin, Olivier Rodrigues, Lionel Verdoucq, Sylvain Merlot, Nathalie Leonhardt, Christophe Maurel

Department of Agronomy and Horticulture: Faculty Publications

Stomatal movements in response to environmental stimuli critically control the plant water status. Although these movements are governed by osmotically driven changes in guard cell volume, the role of membrane water channels (aquaporins) has remained hypothetical. Assays in epidermal peels showed that knockout Arabidopsis thaliana plants lacking the Plasma membrane Intrinsic Protein 2;1 (PIP2;1) aquaporin have a defect in stomatal closure, specifically in response to abscisic acid (ABA). ABA induced a 2-fold increase in osmotic water permeability (P_f) of guard cell protoplasts and an accumulation of reactive oxygen species in guard cells, which were both abrogated in …

Proteomic Profiling Of Maize Opaque Endosperm Mutants Reveals Selective Accumulation Of Lysine-Enriched Proteins, Kyla J. Morton, Shangang Jia, Chi Zhang, David R. Holding

Department of Agronomy and Horticulture: Faculty Publications

Reduced prolamin (zein) accumulation and defective endoplasmic reticulum (ER) body formation occurs in maize opaque endosperm mutants opaque2 (o2), floury2 (fl2), defective endosperm*B30 (DeB30), and Mucronate (Mc), whereas other opaque mutants such as opaque1 (o1) and floury1 (fl1) are normal in these regards. This suggests that other factors contribute to kernel texture. A liquid chromatography approach coupled with tandem mass spectrometry (LC-MS/MS) proteomics was used to compare non-zein proteins of nearly isogenic opaque endosperm mutants. In total, 2762 proteins were identified that were enriched for biological processes such as protein transport and folding, amino acid biosynthesis, …

Tonoplast Sugar Transporters (Sbtsts) Putatively Control Sucrose Accumulation In Sweet Sorghum Stems, Saadia Bihmidine, Benjamin T. Julius, Ismail M. Dweikat, David M. Braun

Department of Agronomy and Horticulture: Faculty Publications

Carbohydrates are differentially partitioned in sweet versus grain sorghums. While the latter preferentially accumulate starch in the grain, the former primarily store large amounts of sucrose in the stem. Previous work determined that neither sucrose metabolizing enzymes nor changes in Sucrose transporter (SUT) gene expression accounted for the carbohydrate partitioning differences. Recently, 2 additional classes of sucrose transport proteins, Tonoplast Sugar Transporters (TSTs) and SWEETs, were identified; thus, we examined whether their expression tracked sucrose accumulation in sweet sorghum stems. We determined 2 TSTs were differentially expressed in sweet vs. grain sorghum stems, likely underlying the massive difference in sucrose …

Selection For Silage Yield And Composition Did Not Affect Genomic Diversity Within The Wisconsin Quality Synthetic Maize Population, Aaron Lorenz, Timothy M. Beissinger, Renato Rodrigues Silva, Natalia De Leon

Department of Agronomy and Horticulture: Faculty Publications

Maize silage is forage of high quality and yield, and represents the second most important use of maize in the United States. The Wisconsin Quality Synthetic (WQS) maize population has undergone five cycles of recurrent selection for silage yield and composition, resulting in a genetically improved population. The application of high-density molecular markers allows breeders and geneticists to identify important loci through association analysis and selection mapping, as well as to monitor changes in the distribution of genetic diversity across the genome. The objectives of this study were to identify loci controlling variation for maize silage traits through association analysis …

A Roadmap For Functional Structural Variants In The Soybean Genome, Justin E. Anderson, Michael B. Kantar, Thomas Y. Kono, Fengli Fu, Adrian O. Stec, Qijian Song, Perry B. Cregan, James E. Specht, Brian W. Diers, Steven B. Cannon, Leah K. Mchale, Robert M. Stupar

Department of Agronomy and Horticulture: Faculty Publications

Gene structural variation (SV) has recently emerged as a key genetic mechanism underlying several important phenotypic traits in crop species. We screened a panel of 41 soybean (Glycine max) accessions serving as parents in a soybean nested association mapping population for deletions and duplications in more than 53,000 gene models. Array hybridization and whole genome resequencing methods were used as complementary technologies to identify SV in 1528 genes, or approximately 2.8%, of the soybean gene models. Although SV occurs throughout the genome, SV enrichment was noted in families of biotic defense response genes. Among accessions, SV was nearly eightfold less …

Overexpression Of The Transporters Atzip1 And Atmtp1 In Cassava Changes Zinc Accumulation And Partitioning, Eliana Gaitán-Solis, Nigel J. Taylor, Dimuth Siritunga, William Stevens, Daniel P. Schachtman

Department of Agronomy and Horticulture: Faculty Publications

Zinc deficiency in humans is a serious problem worldwide with an estimated one third of populations at risk for insufficient zinc in diet, which leads to impairment of cognitive abilities and immune system function. The goal of this research was to increase the bioavailable zinc in the edible portion of cassava roots to improve the overall zinc nutrition of populations that rely on cassava as a dietary staple. To increase zinc concentrations, two Arabidopsis thaliana genes coding for ZIP1 and MTP1 were overexpressed with a tuber-specific or constitutive promoter. Eighteen transgenic events from four constructs, out of a total of …

Differential Expression Analysis In Rna-Seq By A Naive Bayes Classifier With Local Normalization, Yongchao Dou, Xiaomei Guo, Lingling Yuan, David R. Holding, Chi Zhang

Department of Agronomy and Horticulture: Faculty Publications

To improve the applicability of RNA-seq technology, a large number of RNA-seq data analysis methods and correction algorithms have been developed. Although these new methods and algorithms have steadily improved transcriptome analysis, greater prediction accuracy is needed to better guide experimental designs with computational results. In this study, a new tool for the identification of differentially expressed genes with RNA-seq data, named GExposer, was developed. This tool introduces a local normalization algorithm to reduce the bias of nonrandomly positioned read depth. The naive Bayes classifier is employed to integrate fold change, transcript length, and GC content to identify differentially expressed …

Plants Coping Abiotic And Biotic Stresses: A Tale Of Diligent Management, Hatem Rouached, Sikander Pal, Shimon Rachmilevitch, Marc Libault, Lam-Son Phan Tran

Department of Agronomy and Horticulture: Faculty Publications

Plants unlike other living forms are sessile thereby facing severe biotic and abiotic stresses. Plants have evolved different efficient defence responses which thrive upon a number of intrinsic factors, such as genotypic and phenotypic constitutions and developmental circumstances, and extrinsic factors like severity and duration of the stresses. Stress management uses molecular and biochemical level controls, the competence, and speed, at which a stress signal is perceived and transmitted to generate stress signal molecules and activate stress-protective mechanisms. A well-concerted action of the plants’ competence at morphological, physiological, biochemical, and molecular strata regulates numerous adaptive responses to biotic and abiotic …

Dietary Strategies To Influence Appetite: Effects Of Oat Beta-Glucan And Thylakoids From Spinach On Satiety And Reward-Induced Eating Behavior, Candida Joan Rebello

LSU Doctoral Dissertations

The objective of these studies was to examine the effects of oat-based cereals and a spinach extract, on eating behavior. The cereals compared included instant oatmeal (IO), old fashioned oatmeal (SO), and a ready to eat cereal (RTEC), each containing the soluble fiber beta-glucan. The spinach extract containing thylakoids, the internal photosynthetic membrane of plants, was compared with a placebo. The first study, a randomized crossover trial compared the effect of IO and SO on subjective ratings of satiety, with the RTEC. Subjects consumed isocaloric 150kcal servings of the cereals in random order. Visual analogue scale ratings evaluating satiety were …

Identification Of Novel Qtl Governing Root Architectural Traits In An Interspecific Soybean Population, Lakshmi P. Manavalan, Silvas J. Prince, Theresa A. Musket, Julian Chaky, Rupesh Deshmukh, Tri D. Vuong, Li Song, Perry B. Cregan, James C. Nelson, J. Grover Shannon, James E. Specht, Henry T. Nguyen

Department of Agronomy and Horticulture: Faculty Publications

Cultivated soybean (Glycine max L.) cv. Dunbar (PI 552538) and wild G. soja (PI 326582A) exhibited significant differences in root architecture and root-related traits. In this study, phenotypic variability for root traits among 251 BC₂F₅ backcross inbred lines (BILs) developed from the cross Dunbar/PI 326582A were identified. The root systems of the parents and BILs were evaluated in controlled environmental conditions using a cone system at seedling stage. The G. max parent Dunbar contributed phenotypically favorable alleles at a major quantitative trait locus on chromosome 8 (Satt315-I locus) that governed root traits (tap root length and …

Genetic And Molecular Characterization Of Submergence Response Identifies Subtol6 As A Major Submergence Tolerance Locus In Maize, Malachy T. Campbell, Christopher A. Proctor, Yongchao Dou, Aaron J. Schmitz, Piyaporn Phansak, Greg R. Kruger, Chi Zhang, Harkamal Walia

Department of Agronomy and Horticulture: Faculty Publications

Maize is highly sensitive to short term flooding and submergence. Early season flooding reduces germination, survival and growth rate of maize seedlings. We aimed to discover genetic variation for submergence tolerance in maize and elucidate the genetic basis of submergence tolerance through transcriptional profiling and linkage analysis of contrasting genotypes. A diverse set of maize nested association mapping (NAM) founder lines were screened, and two highly tolerant (Mo18Wand M162W) and sensitive (B97 and B73) genotypes were identified. Tolerant lines exhibited delayed senescence and lower oxidative stress levels compared to sensitive lines. Transcriptome analysis was performed on these inbreds to provide …

Allmaps: Robust Scaffold Ordering Based On Multiple Maps, Haibo Tang, Xingtan Zhang, Chenyong Miao, Jisen Zhang, Ray Ming, James C. Schnable, Patrick S. Schnable, Eric Lyons, Jianguo Lu

Department of Agronomy and Horticulture: Faculty Publications

The ordering and orientation of genomic scaffolds to reconstruct chromosomes is an essential step during de novo genome assembly. Because this process utilizes various mapping techniques that each provides an independent line of evidence, a combination of multiple maps can improve the accuracy of the resulting chromosomal assemblies. We present ALLMAPS, a method capable of computing a scaffold ordering that maximizes colinearity across a collection of maps. ALLMAPS is robust against common mapping errors, and generates sequences that are maximally concordant with the input maps. ALLMAPS is a useful tool in building high-quality genome assemblies. ALLMAPS is available at: https://github.com/tanghaibao/jcvi/wiki/ALLMAPS.

Evaluating A Satellite-Based Seasonal Evapotranspiration Product And Identifying Its Relationship With Other Satellite-Derived Products And Crop Yield: A Case Study For Ethiopia, Tsegaye Tadesse, Gabriel B. Senay, Getachew Berhan, Teshome Regassa, Shimelis Beyene

Department of Agronomy and Horticulture: Faculty Publications

Satellite-derived evapotranspiration anomalies and normalized difference vegetation index (NDVI) products from Moderate Resolution Imaging Spectroradiometer (MODIS) data are currently used for African agricultural drought monitoring and food security status assessment. In this study, a process to evaluate satellite-derived evapotranspiration (ETa) products with a geospatial statistical exploratory technique that uses NDVI, satellite-derived rainfall estimate (RFE), and crop yield data has been developed. The main goal of this study was to evaluate the ETa using the NDVI and RFE, and identify a relationship between the ETa and Ethiopia’s cereal crop (i.e., teff, sorghum, corn/maize, barley, and wheat) yields during the main rainy …

From Field To Atlas: Upscaling Of Location-Specific Yield Gap Estimates, Lenny G.J. Van Bussel, Patricio Grassini, Justin Van Wart, Joost Wolf, Lieven Claessens, Haishun Yang, Hendrik Boogaard, Hugo De Groot, Kazuki Saito, Kenneth Cassman, Martin K. Van Ittersum

Department of Agronomy and Horticulture: Faculty Publications

Accurate estimation of yield gaps is only possible for locations where high quality local data are available,which are, however, lacking in many regions of the world. The challenge is how yield gap estimates based on location-specific input data can be used to obtain yield gap estimates for larger spatial areas. Hence,insight about the minimum number of locations required to achieve robust estimates of yield gaps at larger spatial scales is essential because data collection at a large number of locations is expensive and time consuming. In this paper we describe an approach that consists of a climate zonation scheme supplemented …

Effects Of Sowing Date On Phenotypic Plasticity Of Fitness-Related Traits In Two Annual Weeds On The Songnen Plain Of China, Haiyan Li, John L. Lindquist, Yunfei Yang

Department of Agronomy and Horticulture: Faculty Publications

Background Phenotypic plasticity of fitness-related traits is vital for plant species to adapt to variable environments. Chenopodium glaucum L. and Amaranthus retroflexus L. are two common weed species globally. Understanding the plasticity in life-history traits, especially in reproductive allocation, within and among these species is important for predicting their success and for managing them in different environments.

Methodology/Principal Findings Seeds of the two plant species were sown every 10 days from 26 Jun to 15 Aug. Life-history and fitness-related traits of both phenology and morphology were measured, and dry biomass of roots, stems, leaves, and reproductive tissues was determined at …

Assessment Of Rice Self-Sufficiency In 2025 In Eight African Countries, P. A.J. Van Oort, K. Saito, E. Amovin-Assagba, Lenny G.J. Van Bussel, Justin Van Wart, Hugo De Groot, Martin K. Van Ittersum, Kenneth Cassman, M. C.S. Wopereis

Department of Agronomy and Horticulture: Faculty Publications

Most African countries are far from self-sufficient in meeting their rice consumption; in eight countries the production: consumption ratio, ranged from 0.16 to 1.18 in 2012. We show that for the year 2025, with population growth, diet change and yield increase on existing land (intensification), countries cannot become fully self-sufficient in rice. This implies that for the future, a mixture of area expansion and imports will be needed on top of yield gap closure. Further research is needed for identification of most suitable new land for rice area expansion and areas that should be protected.

Fall Seed Guide 2015, Teshome Regassa, P. Stephen Baenziger, Stephen N. Wegulo, Greg Kruger, Dipak K. Santra

Department of Agronomy and Horticulture: Faculty Publications

Crops included in this guide are winter wheat, winter barley, and triticale. You may receive this guide in the mail or through the University of Nebraska Extension network. The data and other information this guide is can be found at our web site: http://cropwatch.unl.edu/varietytest/ and http://www.unl.edu/ncia. Additional information is available at the wheat variety virtual tour web site http://cropwatch.unl.edu/wheat/virtual or the winter wheat variety selection tool page http:// citnews.unl.edu/winter_wheat_tool/index.shtml. The last season was hard on Nebraska winter wheat. Emergence was poor in the west due to dry conditions. On the other hand, some plots in the east had to be …

Advancing Understanding Of The Role Of Belowground Processes In Terrestrial Carbon Sinks Through Ground-Penetrating Radar: Final Report (De-Sc0008099), Frank P. Day

Biological Sciences Faculty Publications

Coarse roots play a significant role in belowground carbon cycling and will likely play an increasingly crucial role in belowground carbon sequestration as atmospheric CO₂ levels continue to rise, yet they are one of the most difficult ecosystem parameters to quantify. Despite promising results with ground-penetrating radar (GPR) as a nondestructive method of quantifying biomass of coarse roots, this application of GPR is in its infancy and neither the complete potential nor limitations of the technology have been fully evaluated. The primary goals and questions of this study fell into four groups: (1) GPR methods: Can GPR detect change …

Dynamic Ocean Management: Defining And Conceptualizing Real-Time Management Of The Ocean, Sara M. Maxwell, Elliot L. Hazen, Rebecca L. Lewison, Danial C. Dunn, Helen Bailey, Steven J. Bograd, Dana K. Briscoe, Sabrina Fossette, Alistair J. Hobday, Meredith Bennett

Biological Sciences Faculty Publications

Most spatial marine management techniques (e.g., marine protected areas) draw stationary boundaries around often mobile marine features, animals, or resource users. While these approaches can work for relatively stationary marine resources, to be most effective marine management must be as fluid in space and time as the resources and users we aim to manage. Instead, a shift towards dynamic ocean management is suggested, defined as management that rapidly changes in space and time in response to changes in the ocean and its users through the integration of near real-time biological, oceanographic, social and/or economic data. Dynamic management can refine the …

Transmission-Blocking Vaccines: Focus On Anti-Vector Vaccines Against Tick-Borne Diseases, Girish Neelakanta, Hameeda Sultana

Biological Sciences Faculty Publications

Tick-borne diseases are a potential threat that account for significant morbidity and mortality in human population worldwide. Vaccines are not available to treat several of the tick-borne diseases. With the emergence and resurgence of several tick-borne diseases, emphasis on the development of transmission-blocking vaccines remains increasing. In this review, we provide a snap shot on some of the potential candidates for the development of anti-vector vaccines (a form of transmission-blocking vaccines) against wide range of hard and soft ticks that include Ixodes, Haemaphysalis, Dermacentor, Amblyomma, Rhipicephalus and Ornithodoros species.

Identification And Comparative Analysis Of Subolesin/Akirin Ortholog From Ornithodoros Turicata Ticks, Hameeda Sultana, Unnati Patel, Daniel E. Sonenshine, Girish Neelakanta

Biological Sciences Faculty Publications

Background: Subolesin is an evolutionary conserved molecule in diverse arthropod species that play an important role in the regulation of genes involved in immune responses, blood digestion, reproduction and development. In this study, we have identified a subolesin ortholog from soft ticks Ornithodoros turicata, the vector of the relapsing fever spirochete in the United States.

Methods: Uninfected fed or unfed O. turicata ticks were used throughout this study. The subolesin mRNA was amplified by reverse transcription polymerase chain reaction (RT-PCR) and sequenced. Quantitative-real time PCR (QRT-PCR) was performed to evaluate subolesin mRNA levels at different O. turicata developmental stages …

Ecological Drivers And Habitat Associations Of Estuarine Bivalves, C. Seabird Mckeon, Björn G. Tunberg, Cora A. Johnston, Daniel J. Barshis

Biological Sciences Faculty Publications

Community composition of the infaunal bivalve fauna of the St. Lucie Estuary and southern Indian River Lagoon, eastern Florida was sampled quarterly for 10 years as part of a long-term benthic monitoring program. A total of 38,514 bivalves of 137 taxa were collected and identified. We utilized this data, along with sediment samples and environmental measurements gathered concurrently, to assess the community composition, distribution, and ecological drivers of the infaunal bivalves of this estuary system. Salinity had the strongest influence on bivalve assemblage across the 15 sites, superseding the influences of sediment type, water turbidity, temperature and other environmental parameters. …

A Popular And Potentially Sustainable Fishery Resource Under Pressure-Extinction Risk And Conservation Of Brazilian Sciaenidae (Teleostei: Perciformes), Ning L. Chao, Flávia L. Frédou, Manuel Haimovici, Monica B. Peres, Beth Polidoro, Marcelo Raseira, Rosana Subira, Kent E. Carpenter

Biological Sciences Faculty Publications

Croakers (Sciaenidae) are major fishery resource in Brazil; constituting 22% of marine and 9% of freshwater fishery landings. Croakers are subject to heavy fishing pressure throughout Brazil, but habitat alteration is also an important threat to regional populations. In this regional Sciaenidae assessment, each species was analyzed for relative risk of extinction, including the identification and quantification of the impact of major threats and existing conservation measures, based on application of the Categories and Criteria of the IUCN Red List of Threatened Species. Of the 52 species of Sciaenid fishes (34 marine and 18 freshwater) present in Brazilian waters, the …

Divergent Responses Of Atlantic Coastal And Oceanic Synechococcus To Iron Limitation, Katherine R. M. Mackey, Anton F. Post, Matthew R. Mcilvin, Gregory A. Cutter, Seth G. John, Mak A. Saito

OES Faculty Publications

Marine Synechococcus are some of the most diverse and ubiquitous phytoplankton, and iron (Fe) is an essential micronutrient that limits productivity in many parts of the ocean. To investigate how coastal and oceanic Atlantic Synechococcus strains acclimate to Fe availability, we compared the growth, photophysiology, and quantitative proteomics of two Synechococcus strains from different Fe regimes. Synechococcus strain WH8102, from a region in the southern Sargasso Sea that receives substantial dust deposition, showed impaired growth and photophysiology as Fe declined, yet used few acclimation responses. Coastal WH8020, from the dynamic, seasonally variable New England shelf, displayed a multitiered, hierarchical cascade …

The Effect Of Fluid Periodization On Athletic Performance Outcomes In American Football Players, Christopher W. Morris

Theses and Dissertations--Kinesiology and Health Promotion

For decades strength and conditioning professionals have been seeking optimal training volumes and intensities to yield maximum performance outcomes without the onset of injury. Unfortunately, current studies apply experimental training techniques without considering the individuals’ response to the imposed training load. Due to the vast genetic variability and extraneous environmental factors that affect one’s ability to recover, results from such studies are controversial and inconclusive. Athlete monitoring systems offer an objective assessment that is purported to evaluate an individual’s physiological readiness to adapt to an overload stimulus and thus allow for daily manipulations in training loads (i.e., fluid periodization). However, …

Effect Of Load Carriage On Tactical Performance, Justin M. Thomas

Theses and Dissertations--Kinesiology and Health Promotion

Special Weapons and Tactics (SWAT) operators are specially trained personnel that are required to carry equipment to perform high risk tasks. Given the need to carry this equipment, it is important to understand the potentially deleterious effect that the additional load may have on tactical performance. Furthermore, it is important to identify physical fitness characteristics that are associated with the potential decrement in performance. Therefore, the purpose of this study was to evaluate the effect of load carriage on tactical performance and identify fitness characteristics associated with any decrement in performance. Twelve male operators performed a simulated tactical test (STT) …

The Effects Of Spinal Manipulative Therapy On Isokinetic Strength And Postactivation Potentiation, Grant D. Sanders

Theses and Dissertations--Kinesiology and Health Promotion

Spinal manipulative therapy (SMT) is a therapeutic procedure employed by various healthcare practitioners for alleviating acute and chronic musculoskeletal complaints. This form of treatment is also delivered to enhance the performance and augment the rehabilitation of athletes. However, despite research findings alleging the strength-modulating effects of SMT alongside numerous professional athletes’ positive anecdotal claims concerning its results, the physiological processes to explain its effects remain largely unexplained. Therefore, the purpose of this work was to investigate the effects of SMT in a college-aged sample population with two experiments.

The first study examined the effect of SMT targeting the lumbosacral region …

An Acid-Bath Technique To Break Seed Dormancy In Common Sunflower, Helianthus L. Annuus (Asteraceae), Yuridia Patricia Gandy, Michael W. Persans, Kenneth R. Summy

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

The phenomenon of seed dormancy is widespread in plants and serves to prevent all or most of a given population from germinating at the “wrong” time, e.g., during an unusually mild fall in an area subject to typically harsh winters. Seed dormancy is an effective survival strategy in many plant populations, but may greatly complicate efforts to establish large cohorts of seedlings (groups of similar age or developmental stage) needed for re-search and other purposes. In an effort to break seed dormancy in common sunflower, Helianthus annuus L. (Asteraceae), we conducted experiments designed to compare germination times and overall germination …

A Program Designed To Address Academic Failure Due To Alcohol Abuse, Frank James Plateroti

Walden Dissertations and Doctoral Studies

This project study addressed the problem of alcohol and binge drinking at a local rural college campus in the Northeast United States and the lack of an effective long-term academic intervention program to address the problem. The purpose of this research study was to determine the prevalence of the problem of the alcohol abuse problem and to develop a long-term program that would respond to the problem of repeat alcohol offenders. Guided by Mezirow’s transformative learning theory, which holds that transformational learning causes changes in a learner that significantly shift the pattern of a learner’s future experiences, this study examined …

Relationships Between A Prenatal Nutrition Education Intervention And Maternal Nutrition In Ethiopia, Divya Lakshmi Selvakumar

Walden Dissertations and Doctoral Studies

In Ethiopia, 17% of pregnant women ages 18-49 are malnourished and have low awareness of prenatal nutrition, which may relate to increasingly high rates of maternal and infant mortality. The purpose of this mixed methods research study was to determine the effects of a community-based prenatal nutrition education intervention program on maternal nutrition knowledge and attitudes in the Alaje district of Ethiopia. The theoretical framework was Sen's capability theory of poverty, in which opportunities can lead to well-being and promote economic development. Research questions focused on the relationships among 8 independent variables-age, income source, degree of program implementation, marital status, …