Life Sciences Commons^™

Engineered Nanoparticles Interact With Nutrients To Intensify Eutrophication In A Wetland Ecosystem Experiment, Marie Simonin, Benjamin P. Colman, Steven M. Anderson, Ryan S. King, Matthew T. Ruis, Astrid Avellan, Christina M. Bergemann, Brittany G. Perrotta, Nicholas K. Geitner, Mengchi Ho, Belen De La Barrera, Jason M. Unrine, Gregory V. Lowry, Curtis J. Richardson, Mark R. Wiesner, Emily S. Bernhardt

Plant and Soil Sciences Faculty Publications

Despite the rapid rise in diversity and quantities of engineered nanomaterials produced, the impacts of these emerging contaminants on the structure and function of ecosystems have received little attention from ecologists. Moreover, little is known about how manufactured nanomaterials may interact with nutrient pollution in altering ecosystem productivity, despite the recognition that eutrophication is the primary water quality issue in freshwater ecosystems worldwide. In this study, we asked two main questions: (1) To what extent do manufactured nanoparticles affect the biomass and productivity of primary producers in wetland ecosystems? (2) How are these impacts mediated by nutrient pollution? To address …

Forage News [2018-09], Department Of Plant And Soil Sciences, University Of Kentucky

Forage News

• Dealing with high nitrates in forage
• New crimson clover, Kentucky Pride, available
• Horse farm sees success from pasture renovations

Near-Infrared Spectroscopy Used To Predict Soybean Seed Germination And Vigour, Maythem Al-Amery, Robert L. Geneve, Mauricio F. Sanches, Paul R. Armstrong, Elizabeth B. Maghirang, Chad Lee, Roberval D. Vieira, David F. Hildebrand

Horticulture Faculty Publications

Rapid, non-destructive methods for measuring seed germination and vigour are valuable. Standard germination and seed vigour were determined using 81 soybean seed lots. From these data, seed lots were separated into high and low germinating seed lots as well as high, medium and low vigour seed lots. Near-infrared spectra (950–1650 nm) were collected for training and validation samples for each seed category and used to create partial least squares (PLS) prediction models. For both germination and vigour, qualitative models provided better discrimination of high and low performing seed lots compared with quantitative models. The qualitative germination prediction models correctly identified …

Characterization Of Mrna Polyadenylation In The Apicomplexa, Ashley T. Stevens, Daniel K. Howe, Arthur G. Hunt

Plant and Soil Sciences Faculty Publications

Messenger RNA polyadenylation is a universal aspect of gene expression in eukaryotes. In well-established model organisms, this process is mediated by a conserved complex of 15–20 subunits. To better understand this process in apicomplexans, a group of unicellular parasites that causes serious disease in humans and livestock, a computational and high throughput sequencing study of the polyadenylation complex and poly(A) sites in several species was conducted. BLAST-based searches for orthologs of the human polyadenylation complex yielded clear matches to only two—poly(A) polymerase and CPSF73—of the 19 proteins used as queries in this analysis. As the human subunits that recognize the …

Japanese Beetles’ Feeding On Milkweed Flowers May Compromise Efforts To Restore Monarch Butterfly Habitat, Adam M. Baker, Daniel A. Potter

Entomology Faculty Publications

The eastern North American migratory population of monarch butterflies (Danaus plexippus) is in serious decline. Habitat restoration, including adding millions of host plants to compensate for loss of milkweed in US cropland, is a key part of the international conservation strategy to return this iconic butterfly to sustainable status. We report here that Popillia japonica, a polyphagous, invasive beetle, aggregates and feeds on flowers of Asclepias syriaca, the monarch’s most important larval food plant, reducing fruiting and seed set by >90% and extensively damaging milkweed umbels in the field. The beetle’s ongoing incursion into the monarch’s …

Double-Stranded Rna Binding Protein, Staufen, Is Required For The Initiation Of Rnai In Coleopteran Insects, June-Sun Yoon, Kanakachari Mogilicherla, Dhandapani Gurusamy, Xien Chen, Shankar C. R. R. Chereddy, Subba R. Palli

Entomology Faculty Publications

RNA interference (RNAi) is being used to develop methods to control pests and disease vectors. RNAi is robust and systemic in coleopteran insects but is quite variable in other insects. The determinants of efficient RNAi in coleopterans, as well as its potential mechanisms of resistance, are not known. RNAi screen identified a double-stranded RNA binding protein (StaufenC) as a major player in RNAi. StaufenC homologs have been identified in only coleopteran insects. Experiments in two coleopteran insects, Leptinotarsa decemlineata and Tribolium castaneum, showed the requirement of StaufenC for RNAi, especially for processing of double-stranded RNA (dsRNA) to small interfering …

Crop Pests And Predators Exhibit Inconsistent Responses To Surrounding Landscape Composition, Daniel S. Karp, Rebecca Chaplin-Kramer, Timothy D. Meehan, Emily A. Martin, Fabrice Declerck, Heather Grab, Claudio Gratton, Lauren Hunt, Ashley E. Larsen, Alejandra Martínez-Salinas, Megan E. O’Rourke, Adrien Rusch, Katja Poveda, Mattias Jonsson, Jay A. Rosenheim, Nancy A. Schellhorn, Teja Tscharntke, Stephen D. Wratten, Wei Zhang, Aaron L. Iverson, Lynn S. Adler, Matthias Albrecht, Audrey Alignier, Gina M. Angelella, Muhammad Zubair Anjum, Jacques Avelino, Péter Batáry, Johannes M. Baveco, Felix J. J. A. Bianchi, Klaus Birkhofer, David J. Gonthier

Entomology Faculty Publications

The idea that noncrop habitat enhances pest control and represents a win–win opportunity to conserve biodiversity and bolster yields has emerged as an agroecological paradigm. However, while noncrop habitat in landscapes surrounding farms sometimes benefits pest predators, natural enemy responses remain heterogeneous across studies and effects on pests are inconclusive. The observed heterogeneity in species responses to noncrop habitat may be biological in origin or could result from variation in how habitat and biocontrol are measured. Here, we use a pest-control database encompassing 132 studies and 6,759 sites worldwide to model natural enemy and pest abundances, predation rates, and crop …

Why Large Seeds With Physical Dormancy Become Nondormant Earlier Than Small Ones, Ailton G. Rodrigues-Junior, Ana Caroline M. P. Mello, Carol C. Baskin, Jerry M. Baskin, Denise M. T. Oliveira, Queila S. Garcia

Biology Faculty Publications

Under natural conditions, large seeds with physical dormancy (PY) may become water permeable earlier than small ones. However, the mechanism for this difference has not been elucidated. Thus, our aim was to evaluate the traits associated with PY in seeds of Senna multijuga (Fabaceae) and to propose a mechanism for earlier dormancy-break in large than in small seeds. Two seedlots were collected and each separated into large and small seeds. Seed dry mass, water content, thickness of palisade layer in the hilar and distal regions and the ratio between palisade layer thickness (P) in the lens fissure and seed mass …

Quantifying Plant Soluble Protein And Digestible Carbohydrate Content, Using Corn (Zea Mays) As An Exemplar, Carrie A. Deans, Gregory A. Sword, Paul A. Lenhart, Eric Burkness, William D. Hutchison, Spencer T. Behmer

Entomology Faculty Publications

Elemental data are commonly used to infer plant quality as a resource to herbivores. However, the ubiquity of carbon in biomolecules, the presence of nitrogen-containing plant defensive compounds, and variation in species-specific correlations between nitrogen and plant protein content all limit the accuracy of these inferences. Additionally, research focused on plant and/or herbivore physiology require a level of accuracy that is not achieved using generalized correlations. The methods presented here offer researchers a clear and rapid protocol for directly measuring plant soluble proteins and digestible carbohydrates, the two plant macronutrients most closely tied to animal physiological performance. The protocols combine …

Managing Herbicide Resistance: Listening To The Perspectives Of Practitioners. Procedures For Conducting Listening Sessions And An Evaluation Of The Process, Jill Schroeder, Michael Barrett, David R. Shaw, Amy B. Asmus, Harold Coble, David Ervin, Raymond A. Jussaume Jr., Micheal D. K. Owen, Ian Burke, Cody F. Creech, A. Stanley Culpepper, William S. Curran, Darrin M. Dodds, Todd A. Gaines, Jeffrey L. Gunsolus, Bradley D. Hanson, Prashant Jha, Annie E. Klodd, Andrew R. Kniss, Ramon G. Leon, Sandra Mcdonald, Don W. Morishita, Brian J. Schutte, Christy L. Sprague, Phillip W. Stahlman, Larry E. Steckel, Mark J. Vangessel

Plant and Soil Sciences Faculty Publications

Seven half-day regional listening sessions were held between December 2016 and April 2017 with groups of diverse stakeholders on the issues and potential solutions for herbicide-resistance management. The objective of the listening sessions was to connect with stakeholders and hear their challenges and recommendations for addressing herbicide resistance. The coordinating team hired Strategic Conservation Solutions, LLC, to facilitate all the sessions. They and the coordinating team used in-person meetings, teleconferences, and email to communicate and coordinate the activities leading up to each regional listening session. The agenda was the same across all sessions and included small-group discussions followed by reporting …

Forage News [2018-08], Department Of Plant And Soil Sciences, University Of Kentucky

Forage News

• Plan your fall seeding now
• Submitting plant samples for diagnosis
• Minimize alfalfa crown rot with potassium

Plant And Microbial Responses To Repeated Cu(Oh)2 Nanopesticide Exposures Under Different Fertilization Levels In An Agro-Ecosystem, Marie Simonin, Benjamin P. Colman, Weiyi Tang, Jonathan D. Judy, Steven M. Anderson, Christina M. Bergemann, Jennifer D. Rocca, Jason M. Unrine, Nicolas Cassar, Emily S. Bernhardt

Plant and Soil Sciences Faculty Publications

The environmental fate and potential impacts of nanopesticides on agroecosystems under realistic agricultural conditions are poorly understood. As a result, the benefits and risks of these novel formulations compared to the conventional products are currently unclear. Here, we examined the effects of repeated realistic exposures of the Cu(OH)₂ nanopesticide, Kocide 3000, on simulated agricultural pastureland in an outdoor mesocosm experiment over 1 year. The Kocide applications were performed alongside three different mineral fertilization levels (Ambient, Low, and High) to assess the environmental impacts of this nanopesticide under low-input or conventional farming scenarios. The effects of Kocide over time were …

Genome-Wide Atlas Of Alternative Polyadenylation In The Forage Legume Red Clover, Manohar Chakrabarti, Randy D. Dinkins, Arthur G. Hunt

Plant and Soil Sciences Faculty Publications

Studies on prevalence and significance of alternative polyadenylation (APA) in plants have been so far limited mostly to the model plants. Here, a genome-wide analysis of APA was carried out in different tissue types in the non-model forage legume red clover (Trifolium pratense L). A profile of poly(A) sites in different tissue types was generated using so-called ‘poly(A)-tag sequencing’ (PATseq) approach. Our analysis revealed tissue-wise dynamics of usage of poly(A) sites located at different genomic locations. We also identified poly(A) sites and underlying genes displaying APA in different tissues. Functional categories enriched in groups of genes manifesting APA between …

Forage News [2018-07], Department Of Plant And Soil Sciences, University Of Kentucky

Forage News

• Western KY KFGC Field Day, August 7^th
• Managing Windrow Disease in Alfalfa
• Baleage Basics

A Broad Spectrum Racemase In Pseudomonas Putida Kt2440 Plays A Key Role In Amino Acid Catabolism, Atanas D. Radkov, Luke A. Moe

Plant and Soil Sciences Faculty Publications

The broad-spectrum amino acid racemase (Alr) of Pseudomonas putida KT2440 preferentially interconverts the L- and D-stereoisomers of Lys and Arg. Despite conservation of broad-spectrum racemases among bacteria, little is known regarding their physiological role. Here we explore potential functional roles for Alr in P. putida KT2440. We demonstrate through cellular fractionation that Alr enzymatic activity is found in the periplasm, consistent with its putative periplasm targeting sequence. Specific activity of Alr is highest during exponential growth, and this activity corresponds with an increased accumulation of D-Lys in the growth medium. An alr gene knockout strain (Δalr) was generated …

Plants Pre-Infested With Viruliferous Med/Q Cryptic Species Promotes Subsequent Bemisia Tabaci Infestation, Xiaobin Shi, Gong Chen, Huipeng Pan, Wen Xie, Qingjun Wu, Shaoli Wang, Yong Liu, Xuguo Zhou, Youjun Zhang

Entomology Faculty Publications

The sweet potato whitefly, Bemisia tabaci, is one of the most invasive insect pests worldwide. The two most destructive whitefly cryptic species are MEAM1/B and MED/Q. Given that MED/Q has replaced MEAM1/B in China and the invasion of MED/Q has coincided with the outbreak of tomato yellow leaf curl virus (TYLCV), we hypothesize that pre-infestation with viruliferous B. tabaci will affect the subsequent host preferences. To test this hypothesis, we (1) conducted bioassays to compare the host preference of viruliferous and non-viruliferous MEAM1/B and MED/Q, respectively, on plants pre-infested with viruliferous and non-viruliferous MEAM1/B and MED/Q; (2) profiled plant …

Different Patterns Of Colonization Of Oxalis Alpina In The Sky Islands Of The Sonoran Desert Via Pollen And Seed Flow, Jessica Pérez‐Alquicira, Stephen G. Weller, César A. Domínguez, Francisco E. Molina-Freaner, Olga V. Tsyusko

Plant and Soil Sciences Faculty Publications

Historical factors such as climatic oscillations during the Pleistocene epoch have dramatically impacted species distributions. Studies of the patterns of genetic structure in angiosperm species using molecular markers with different modes of inheritance contribute to a better understanding of potential differences in colonization and patterns of gene flow via pollen and seeds. These markers may also provide insights into the evolution of reproductive systems in plants. Oxalis alpina is a tetraploid, herbaceous species inhabiting the Sky Island region of the southwestern United States and northern Mexico. Our main objective in this study was to analyze the influence of climatic oscillations …

Salt Stress Induces Non-Cg Methylation In Coding Regions Of Barley Seedlings (Hordeum Vulgare), Moumouni Konate, Michael J. Wilkinson, Benjamin T. Mayne, Stephen M. Pederson, Eileen S. Scott, Bettina Berger, Carlos M. Rodriguez Lopez

Horticulture Faculty Publications

Salinity can negatively impact crop growth and yield. Changes in DNA methylation are known to occur when plants are challenged by stress and have been associated with the regulation of stress-response genes. However, the role of DNA-methylation in moderating gene expression in response to salt stress has been relatively poorly studied among crops such as barley. Here, we assessed the extent of salt-induced alterations of DNA methylation in barley and their putative role in perturbed gene expression. Using Next Generation Sequencing, we screened the leaf and root methylomes of five divergent barley varieties grown under control and three salt concentrations, …

A Shared Cis-Regulatory Module Activates Transcription In The Suspensor Of Plant Embryos, Kelli F. Henry, Anhthu Q. Bui, Tomokazu Kawashima, Robert B. Goldberg

Plant and Soil Sciences Faculty Publications

The mechanisms controlling the transcription of gene sets in specific regions of a plant embryo shortly after fertilization remain unknown. Previously, we showed that G564 mRNA, encoding a protein of unknown function, accumulates to high levels in the giant suspensor of both Scarlet Runner Bean (SRB) and Common Bean embryos, and a cis-regulatory module containing three unique DNA sequences, designated as the 10-bp, Region 2, and Fifth motifs, is required for G564 suspensor-specific transcription [Henry KF, et al. (2015) Plant Mol Biol 88:207–217; Kawashima T, et al. (2009) Proc Natl Acad Sci USA 106:3627–3632]. We tested the hypothesis that …

Agronomic And Chemical Performance Of Field-Grown Tobacco Engineered For Triterpene And Methylated Triterpene Metabolism, Zuodong Jiang, Chase Kempinski, Santosh Kumar, Scott Kinison, Kristin Linscott, Eric Nybo, Sarah Janze, Constance Wood, Joseph Chappell

Pharmaceutical Sciences Faculty Publications

Squalene is a linear intermediate to nearly all classes of triterpenes and sterols and is itself highly valued for its use in wide range of industrial applications. Another unique linear triterpene is botryococcene and its methylated derivatives generated by the alga Botryococcus braunii race B, which are progenitors to fossil fuel deposits. Production of these linear triterpenes was previously engineered into transgenic tobacco by introducing the key steps of triterpene metabolism into the particular subcellular compartments. In this study, the agronomic characteristics (height, biomass accumulation, leaf area), the photosynthetic capacity (photosynthesis rate, conductance, internal CO₂ levels) and triterpene content …

Forage News [2018-06], Department Of Plant And Soil Sciences, University Of Kentucky

Forage News

• New Publication – Crabgrass as Forage (AGR-232)
• New Publication – Foxtail Millet (AGR-233)
• Sivanto Prime (insecticide) Available on Sweet Sorghum for 2018

Pipecolic Acid Confers Systemic Immunity By Regulating Free Radicals, Caixia Wang, Ruiying Liu, Gah-Hyun Lim, Laura De Lorenzo, Keshun Yu, Kai Zhang, Arthur G. Hunt, Aardra Kachroo, Pradeep Kachroo

Plant Pathology Faculty Publications

Pipecolic acid (Pip), a non-proteinaceous product of lysine catabolism, is an important regulator of immunity in plants and humans alike. In plants, Pip accumulates upon pathogen infection and has been associated with systemic acquired resistance (SAR). However, the molecular mechanisms underlying Pip-mediated signaling and its relationship to other known SAR inducers remain unknown. We show that in plants, Pip confers SAR by increasing levels of the free radicals, nitric oxide (NO), and reactive oxygen species (ROS), which act upstream of glycerol-3-phosphate (G3P). Plants defective in NO, ROS, G3P, or salicylic acid (SA) biosynthesis accumulate reduced Pip in their distal uninfected …

Photocatalytic Degradation Of Dimethoate In Bok Choy Using Cerium-Doped Nano Titanium Dioxide, Xiangying Liu, Yu Li, Xuguo Zhou, Kun Luo, Lifeng Hu, Kailin Liu, Lianyang Bai

Entomology Faculty Publications

Dimethoate, a systemic insecticide, has been used extensively in vegetable production. Insecticide residues in treated vegetables, however, pose a potential risk to consumers. Photocatalytic degradation is a new alternative to managing pesticide residues. In this study, the degradation of dimethoate in Bok choy was investigated under the field conditions using cerium-doped nano titanium dioxide (TiO₂/Ce) hydrosol as a photocatalyst. The results show that TiO₂/Ce hydrosol can accelerate the degradation of dimethoate in Bok choy. Specifically, the application of TiO₂/Ce hydrosol significantly increased the reactive oxygen species (ROS) contents in the treated Bok choy, which …

Deletion Of Endo-Β-1,4-Xylanase Vmxyl1 Impacts The Virulence Of Valsa Mali In Apple Tree, Chunlei Yu, Ting Li, Xiangpeng Shi, Muhammad Saleem, Baohua Li, Wenxing Liang, Caixia Wang

Plant and Soil Sciences Faculty Publications

Valsa mali, a parasitic fungus, is a destructive pathogen of apple tree that causes heavy economic losses in China. The pathogen secretes various cell wall-degrading enzymes (CWDEs) that degrade plant cell-wall components, and thus facilitate its entry into host cells. Therefore, functional analysis of the genes encoding CWDEs is necessary to understand virulence of V. mali toward apple tree. Here, we identified and cloned an endo-β-1,4-xylanase gene, VmXyl1 in V. mali. The full-length cDNA of VmXyl1 is 1626 bp containing 5′- and 3′-non-coding regions, as well an open reading frame of 1320 bp that encodes a protein with …

Assembly-Hub Function Of Er-Localized Snare Proteins In Biogenesis Of Tombusvirus Replication Compartment, Zsuzsanna Sasvari, Nikolay Kovalev, Paulina Alatriste Gonzalez, Kai Xu, Peter D. Nagy

Plant Pathology Faculty Publications

Positive-strand RNA viruses assemble numerous membrane-bound viral replicase complexes within large replication compartments to support their replication in infected cells. Yet the detailed mechanism of how given subcellular compartments are subverted by viruses is incompletely understood. Although, Tomato bushy stunt virus (TBSV) uses peroxisomal membranes for replication, in this paper, we show evidence that the ER-resident SNARE (soluble NSF attachment protein receptor) proteins play critical roles in the formation of active replicase complexes in yeast model host and in plants. Depletion of the syntaxin 18-like Ufe1 and Use1, which are components of the ER SNARE complex in the ERAS (ER …

Cloning And Characterization Of A Pyrethroid Pesticide Decomposing Esterase Gene, Est3385, From Rhodopseudomonas Palustris Psb-S, Xiangwen Luo, Deyong Zhang, Xuguo Zhou, Jiao Du, Songbai Zhang, Yong Liu

Entomology Faculty Publications

Full length open reading frame of pyrethroid detoxification gene, Est3385, contains 963 nucleotides. This gene was identified and cloned based on the genome sequence of Rhodopseudomonas palustris PSB-S available at the GneBank. The predicted amino acid sequence of Est3385 shared moderate identities (30–46%) with the known homologous esterases. Phylogenetic analysis revealed that Est3385 was a member in the esterase family I. Recombinant Est3385 was heterologous expressed in E. coli, purified and characterized for its substrate specificity, kinetics and stability under various conditions. The optimal temperature and pH for Est3385 were 35 °C and 6.0, respectively. This enzyme could …

Gwas For Fusarium Head Blight Related Traits In Winter Wheat (Triticum Aestivum L.) In An Artificially Warmed Treatment, Elisane W. Tessmann, David A. Van Sanford

Plant and Soil Sciences Faculty Publications

Global temperature increases will affect Fusarium head blight (FHB) levels in wheat (Triticum aestivum L.). A pressing question is whether current sources of resistance will be effective in a warmer environment. We evaluated phenotypic response to disease in 238 soft winter wheat breeding lines and cultivars grown in 2015–2016 and 2016–2017 under control and warmed (+3 °C) conditions. Warming was achieved with heating cables buried 3 cm in the rhizosphere. We measured heading date, plant height, yield, FHB rating, Fusarium damaged kernels (FDK), deoxynivalenol (DON), leaf blotch rating, powdery mildew rating and leaf rust rating. There were significant ( …

Forage News [2018-05], Department Of Plant And Soil Sciences, University Of Kentucky

Forage News

• Value of Cutting Hay Earlier
• Guide to successfully replacing endophyte-infected KY-31 pastures with Novel Endophyte Tall Fescue
• Alfalfa – Third Most Valuable Field Crop in U.S.

Comparison Of Cultivation Methods Impact On Playability Of Agrostis Stolonifera Greens, K. Dickson, J. Sorochan, Gregg Munshaw, A. Thomas

Plant and Soil Sciences Faculty Publications

Creeping bentrgrass putting greens require intense management due to stoloniferous growth (thatch accumulation) and excessive wear and traffic by equipment and golfers. Increases in thatch and soil compaction are often managed with cultivation practices, which lead to downtime for golfers. Field research was conducted in Knoxville, TN, and Elizabethtown, KY, to compare new and traditional cultivation methods for their impact on playability on creeping bentgrass putting greens. Treatments included air injection, dry sand injection, solid tine cultivation topdressed with sand, hollow tine cultivation topdressed with sand, and non-treated control. Treatments were arranged in a randomized complete block design replicated three …

Advancing The Understanding Of Environmental Transformations, Bioavailability And Effects Of Nanomaterials, An International Us Environmental Protection Agency—Uk Environmental Nanoscience Initiative Joint Program, Mitch M. Lasat, Kian Fan Chung, Jamie Lead, Steve Mcgrath, Richard J. Owen, Sophie Rocks, Jason M. Unrine, Junfeng Zhang

Plant and Soil Sciences Faculty Publications

Nanotechnology has significant economic, health, and environmental benefits, including renewable energy and innovative environmental solutions. Manufactured nanoparticles have been incorporated into new materials and products because of their novel or enhanced properties. These very same properties also have prompted concerns about the potential environmental and human health hazard and risk posed by the manufactured nanomaterials. Appropriate risk management responses require the development of models capable of predicting the environmental and human health effects of the nanomaterials. Development of predictive models has been hampered by a lack of information concerning the environmental fate, behavior and effects of manufactured nanoparticles. The United …