Life Sciences Commons^™

A Comparative Genomic Analysis Of Putative Pathogenicity Genes In The Host-Specific Sibling Species Colletotrichum Graminicola And Colletotrichum Sublineola, Ester A. S. Buiate, Katia Viana Xavier, Neil Moore, Maria F. Torres, Mark L. Farman, Christopher L. Schardl, Lisa J. Vaillancourt

Plant Pathology Faculty Publications

Background: Colletotrichum graminicola and C. sublineola cause anthracnose leaf and stalk diseases of maize and sorghum, respectively. In spite of their close evolutionary relationship, the two species are completely host-specific. Host specificity is often attributed to pathogen virulence factors, including specialized secondary metabolites (SSM), and small-secreted protein (SSP) effectors. Genes relevant to these categories were manually annotated in two co-occurring, contemporaneous strains of C. graminicola and C. sublineola. A comparative genomic and phylogenetic analysis was performed to address the evolutionary relationships among these and other divergent gene families in the two strains.

Results: Inoculation of maize with C. sublineola …

Effect Of Seed Morph And Light Level On Growth And Reproduction Of The Amphicarpic Plant Amphicarpaea Edgeworthii (Fabaceae), Keliang Zhang, Jerry M. Baskin, Carol C. Baskin, Xuejun Yang, Zhenying Huang

Biology Faculty Publications

Amphicarpic plants produce aerial and subterranean fruits on an individual plant, and these heteromorphic diaspores give rise to plants that differ in growth and ecology. Amphicarpaea edgeworthii is a summer annual amphicarpic species that grows over a range of light levels. We aimed to compare the response to shading intensity of plants of A. edgeworthii grown throughout their life cycle from aerial seeds (ASP) and from subterranean seeds (SSP). We hypothesized that vegetative and reproductive growth of plants from ASP and SSP respond differently to light. Plants were grown from ASP and SSP under 0, 46, 71 and 90% shading …

Three-Dimensional Imaging Of The Intracellular Assembly Of A Functional Viral Rna Replicase Complex, Isabel Fernández De Castro, José J. Fernández, Daniel Barajas, Peter D. Nagy, Cristina Risco

Plant Pathology Faculty Publications

Positive-strand RNA viruses, which can be devastating pathogens in humans, animals and plants, replicate their genomes on intracellular membranes. Here, we describe the three-dimensional ultrastructural organization of a tombusvirus replicase in yeast, a valuable model for exploring virus–host interactions. We visualized the intracellular distribution of a viral replicase protein using metal-tagging transmission electron microscopy, a highly sensitive nanotechnology whose full potential remains to be developed. These three-dimensional images show how viral replicase molecules are organized when they are incorporated into the active domains of the intracellular replication compartment. Our approach provides a means to study protein activation mechanisms in cells …

The Family Rhabdoviridae: Mono- And Bipartite Negative-Sense Rna Viruses With Diverse Genome Organization And Common Evolutionary Origins, Ralf G. Dietzgen, Hideki Kondo, Michael M. Goodin, Gael Kurath, Nikos Vasilakis

Plant Pathology Faculty Publications

The family Rhabdoviridae consists of mostly enveloped, bullet-shaped or bacilliform viruses with a negative-sense, single-stranded RNA genome that infect vertebrates, invertebrates or plants. This ecological diversity is reflected by the diversity and complexity of their genomes. Five canonical structural protein genes are conserved in all rhabdoviruses, but may be overprinted, overlapped or interspersed with several novel and diverse accessory genes. This review gives an overview of the characteristics and diversity of rhabdoviruses, their taxonomic classification, replication mechanism, properties of classical rhabdoviruses such as rabies virus and rhabdoviruses with complex genomes, rhabdoviruses infecting aquatic species, and plant rhabdoviruses with both mono- …

Toward Biochemical Conversion Of Lignocellulose On-Farm: Pretreatment And Hydrolysis Of Corn Stover In Situ, Alicia A. Modenbach, Sue E. Nokes, Michael D. Montross, Barbara L. Knutson

Biosystems and Agricultural Engineering Faculty Publications

High-solids lignocellulosic pretreatment using NaOH followed by high-solids enzymatic hydrolysis was evaluated for an on-farm biochemical conversion process. Increasing the solids loadings for these processes has the potential for increasing glucose concentrations and downstream ethanol production; however, sequential processing at high-solids loading similar to an on-farm cellulose conversion system has not been studied. This research quantified the effects of high-solids pretreatment with NaOH and subsequent high-solids enzymatic hydrolysis on cellulose conversion. As expected, conversion efficiency was reduced; however, the highest glucose concentration (40.2 g L^-1), and therefore the highest potential ethanol concentration, resulted from the high-solids combined pretreatment …

Field-Observed Angles Of Repose For Stored Grain In The United States, Rumela Bhadra, Mark E. Casada, Sidney A. Thompson, Josephine M. Boac, Ronaldo G. Maghirang, Michael D. Montross, Aaron P. Turner, Samuel G. Mcneill

Biosystems and Agricultural Engineering Faculty Publications

Bulk grain angle of repose (AoR) is a key parameter for inventorying grain, predicting flow characteristics, and designing bins and grain handling systems. The AoR is defined for two cases, piling (dynamic) or emptying (static), and usually varies with grain type. The objective of this study was to measure piling angles of repose for corn, sorghum, barley, soybeans, oats, and hard red winter (HRW) wheat in steel and concrete bins in the United States. Angles were measured in 182 bins and 7 outdoor piles. The piling AoR for corn ranged from 15.7° to 30.2° (median of 20.4° and standard deviation …

Forage News [2017-01], Department Of Plant And Soil Sciences, University Of Kentucky

Forage News

• 2016 Long-Term Summary of Kentucky Forage Variety Trials
• Purchase Improved Clovers for Frost Seeding NOW
• Roundup-Ready Alfalfa Variety Differences
• Understanding and Improving Fermentation in Alfalfa and Grass Baleage

Physiological Changes Associated With Pregnant Or Nonpregnant Mares Grazing Pastures Of Orchardgrass-Bluegrass, Kentucky 31 Tall Fescue Infected With Epichloë Coenophiala, Or Kyfa9821 Tall Fescue Infected With The Novel Endophyte Ar584, Victoria A. Taylor

Theses and Dissertations--Veterinary Science

Kentucky 31 tall fescue (KY31) infected with the common toxic endophyte strains of Epichloё coenophiala produces toxic alkaloids that improve plant vigor, but cause numerous adverse effects in grazing animals. Researchers developed a variety of KY31 containing an alternative strain of E. coenophiala, termed novel endophyte (NE). Adverse health effects in mares have not been evaluated.

Experiments in this thesis tested the hypothesis that the NE pasture does not cause adverse effects typically associated with KY31. Specific aims were to: 1) compare forage ergovaline concentrations between KY31 vs NE pastures; 2) evaluate palmar artery diameters in mares grazing KY31, …

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 …

A Method For Reflectance Index Wavelength Selection From Moisture-Controlled Soil And Crop Residue Samples, Ali Hamidisepehr, Michael P. Sama, Aaron P. Turner, Ole O. Wendroth

Biosystems and Agricultural Engineering Faculty Publications

Reflectance indices are a method for reducing the dimensionality of spectral measurements used to quantify material properties. Choosing the optimal wavelengths for developing an index based on a given material and property of interest is made difficult by the large number of wavelengths typically available to choose from and the lack of homogeneity when remotely sensing agricultural materials. This study aimed to determine the feasibility of using a low-cost method for sensing the moisture content of background materials in traditional crop remote sensing. Moisture-controlled soil and wheat stalk residue samples were measured at varying heights using a reflectance probe connected …

Sexual Dimorphism In The Moss Bryum Argenteum And Its Implications For Sex Ratio Bias, Jonathan David Moore Iii

Theses and Dissertations--Biology

In dioecious plants, selection due to sex function differences has produced sex-specific life histories, morphologies, and physiologies. In many dioecious seed plants, dimorphisms and population sex ratios have been plausibly linked, but similar links are not yet apparent in dioecious bryophytes. Population sex ratio bias is often expected to favor the sex with lower investment in sexual reproduction, especially in resource-poor environments. Unlike in seed plants, bryophyte males may have higher average reproductive investment than females, which typically have low offspring production rates due to sperm limitation. However, traits aside from reproductive investment such as shoot and leaf arrangement may …

Equilibrium Moisture Content Of Kabuli, Chickpea, Black Sesame, And White Sesame Seeds, Paul R. Armstrong, Elizabeth B. Maghirang, Bhadriraju Subramanyam, Samuel G. Mcneill

Biosystems and Agricultural Engineering Faculty Publications

Sesame and chickpea are important crops in Ethiopia because both are major export crops that generate much revenue for both small farmers and the country as a whole. However, there is a lack of information about the fundamental equilibrium moisture content (EMC) relationships among these crops, which would help facilitate better monitoring and storage. Therefore, EMC adsorption and desorption prediction models based on temperature (T) and relative humidity (RH) were developed for the modified Chung-Pfost and modified Henderson models for Kabuli chickpea (KC), black sesame (BS), and white sesame (WS) seeds. The samples for conducting the adsorption and desorption tests …

Evaluating Soil Physical And Chemical Properties Following Addition Of Non-Composted Spent Coffee And Tea For Athletic Fields, Shuang Zhou

Theses and Dissertations--Plant and Soil Sciences

Physical and chemical properties of non-composted spent coffee (CF) and tea (T) suggest they may have applications as soil amendments for improving poor soils. Studies were conducted to determine 1) the effect of amendments on grass growth and soil properties, 2) the effect of incorporation versus surface application of amendments on soil properties, and 3) the effect of amendment application frequency on grass growth and soil properties. In the first study, amendments were mixed with sand and planted to bermudagrass. Treatments included CF, T, and peat moss (PM) mixed with sand, and 100% sand as a control. In the second …

Invasion Dynamics Of The Exotic Liana Euonymus Fortunei (Turcz.) Hand.-Mazz. (Wintercreeper), Todd J. Rounsaville

Theses and Dissertations--Biology

Elevated atmospheric CO₂ has been implicated as a driver of increased liana abundance worldwide. Known as disturbance creators and beneficiaries, lianas possess the potential to significantly influence forest ecosystems. I investigated the early-invasion dynamics of Euonymus fortunei (wintercreeper), an evergreen liana that is invading forests in eastern North America, disrupting native plant communities and ecosystem functions.

Wintercreeper is widely cultivated as an ornamental groundcover, frequently invading natural areas via asexual stem growth. Invasion of remote natural areas is dependent upon seed transport and may occur less frequently. I examined the mechanisms of seed dormancy by conducting a ‘move-along’ experiment …

Evaluating Nonstructural Carbohydrate Variation Of Cool-Season Grasses Based On Genotype, Management And Environment, Kelly Joan Prince

Theses and Dissertations--Plant and Soil Sciences

Understanding how nonstructural carbohydrates fluctuate in pastures and being able to quantify them is an essential component in successfully managing grazing animals that may require high or low nonstructural carbohydrate diets. The objectives of this study were 1) to evaluate the effects of genotype, management, and environment on water-soluble carbohydrates (WSC) and ethanol-soluble carbohydrates (ESC) in cool-season grass pastures in central Kentucky, and 2) to develop near-infrared reflectance spectroscopy (NIRS) equations to predict WSC and ESC in cool-season grasses. Ten cool-season grass cultivars consisting of Kentucky bluegrass, tall fescue, orchardgrass and perennial ryegrass were sampled in the morning and afternoon …

Increasing Renewable Oil Content And Utility, William Richard Serson

Theses and Dissertations--Plant and Soil Sciences

Since the dawn of agriculture man has been genetically modifying crop plants to increase yield, quality and utility. In addition to selective breeding and hybridization we can utilize mutant populations and biotechnology to have greater control over crop plant modification than ever before. Increasing the production of plant oils such as soybean oil as a renewable resource for food and fuel is valuable. Successful breeding for higher oil levels in soybean, however, usually results in reduced protein, a second valuable seed component. We show that by manipulating a highly active acyl-CoA: diacylglycerol acyltransferase (DGAT) the hydrocarbon flux to oil in …

Impact Of A High Oil And Protein On Agronomic Traits And Overall Seed Composition In Soybean, Maythem Al-Amery

Theses and Dissertations--Plant and Soil Sciences

New soybean lines have been developed with significantly higher oil, protein + oil and higher meal protein. These soybeans contain a VgD1 gene (highly active acyl-CoA:diacylglycerol acyltransferase, DGAT from Vernonia galamensis (VgDGAT1A) produces much higher oil synthesis and accumulation activity in soybean. Soybean with active DGAT from Vernonia galamensis (VgDGAT1A) has active TAG biosynthesis relative to other DGATs including from soybeans and Arabidopsis. DGATs catalyze the final step of TAG synthesis: DAG (diacylglycerol) + acyl-CoA → TAG + CoASH (Coenzyme A is notable for its role in the synthesis and oxidation of fatty acids, and the oxidation of pyruvate in …