Plant Sciences Commons^™

Hyaluronan Synthase Of Chlorella Virus Pbcv-1, Paul L. Deangelis, Wei Jing, Michael V. Graves, Dwight E. Burbank, James L. Van Etten

Department of Plant Pathology: Faculty Publications

Sequence analysis of the 330-kilobase genome of the virus PBCV-1 that infects a chlorella-like green algae revealed an open reading frame, A98R, with similarity to several hyaluronan synthases. Hyaluronan is an essential polysaccharide found in higher animals as well as in a few pathogenic bacteria. Expression of the A98R gene product in Escherichia coli indicated that the recombinant protein is an authentic hyaluronan synthase. A98R is expressed early in PBCV-1 infection and hyaluronan is produced in infected algae. These results demonstrate that a virus can encode an enzyme capable of synthesizing a carbohydrate polymer and that hyaluronan exists outside of …

Nebraska Range Shortcourse: A Successful Approach To Continuing Education, Daniel R. Vaughn, Anthony D. Watson, Lowell E. Moser, Walter H. Schacht

Department of Agronomy and Horticulture: Faculty Publications

Casual visitors to Nebraska rarely see the diversity of the 23 million acres of its rangeland. The state boasts of its nonparalleled range beef cattle industry which relies heavily on the Sandhills, a seemingly endless expanse of grass-covered dunes. In sharp contrast to the Sandhills, however, is a wide array of landscapes including the pine ridge of northern Nebraska, the sagebrush grassland of the southwestern region, the shortgrass prairie of the panhandle, the highly-dissected loess hills, and wooded river valleys. These landscapes offer a complex mixture of habitats, recreational opportunities, rangeland products, and management challenges. People with varied education and …

The Prairie Naturalist Volume 29, No.4. December 1997

The Prairie Naturalist

BUTTERFLY SPECIES IN NATIVE PRAIRIE AND RESTORED PRAIRIE ▪ D. M. Debinski and A. M. Babbit

BACK-CALCULATED LENGTH-AT-AGE ESTIMATES FROM TWO SCALE RADII ▪ K. L. Hurley, K. L. Pope, and D. W. Willis

DIET OF NORTH DAKOTA ELK DETERMINED FROM RUMEN AND FECAL ANALYSES ▪ R. G. Osborn, J. A. Jenks, and W. F. Jensen

INTERSPECIFIC COMPETITION FOR FOOD BETWEEN WHITE-FOOTED MICE AND EASTERN WOODRATS ▪ B. G. Aloiau, D. M. Post, and E. A. Home

NESTING PIPING PLOVER AND LEAST TERN ON THE KANSAS RIVER ▪ W. H. Busby, D. W. Mulhern, P. G. Kramos, and D. A. …

Growing Degree-Days: One Equation, Two Interpretations, Gregory S. Mcmaster, Wallace Wilhelm

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

Heat units, expressed in growing degree-days (GDD), are frequently used to describe the timing of biological processes. The basic equation used is GDD = [(T_MAX + T_MIN)/2] - T_BASE where T_MAX and T_MIN are daily maximum and minimum air temperature, respectively, and T_BASE is the base temperature. Two methods of interpreting this equation for calculating GDD are: (1) if the daily mean temperature is less than the base, it is set equal to the base temperature, or (2) if T_MAX or T_MIN < T_BASE they are reset equal to T …

Morphological Development Of Switchgrass As Affected By Planting Date, Alexander J. Smart, Lowell E. Moser

Department of Agronomy and Horticulture: Faculty Publications

Late-spring and early-summer plantings of warm-season grasses often fail, due to dry soil conditions and competition from annual grass and broadleaf weeds. The objective of this study was to compare the morphological development of switchgrass (Panicum virgatum L.) planted in early, mid, and late spring in eastern Nebraska. This study was conducted in 1994 and 1995 at Lincoln, NE, on a Kennebec silt loam (fine-silty, mixed, mesic Cumulic Hapludolls). 'Blackwell' and 'Trailblazer' switchgrass were planted in mid-March, late April, and late May using a single-row, precision grass-seed cone planter to a depth of 0.6 to 1.3 cm at 98 …

Cdna Encoding A Reca Homolog In Eukaryotes, Andre Jagendorf, Heriberto D. Cerutti

Center for Plant Science Innovation: Faculty and Staff Publications

A nucleotide and deduced amino acid sequence of a cDNA encoding the Arabidopsis thulium RecA protein is disclosed.

Identification Of The Wheat Curl Mite As The Vector Of The High Plains Virus Of Corn And Wheat, Dallas L. Seifers, Tom L. Harvey, T. J. Martin, Stanley G. Jensen

Department of Plant Pathology: Faculty Publications

Wheat with virus-like symptoms (extracts containing a 33-kDa protein in sodium dodecyl sulfate- polyacrylamide gel electrophoresis, negative in enzyme-linked immunosorbent assay to wheat streak mosaic virus, and not infectious in a backassay to other wheat) reacted positively to antiserum made against a protein purified from symptomatic corn infected with the High Plains virus (HPV), indicating a serological relationship between the corn and wheat pathogens. The wheat curl mite (WCM, Aceria tosichella Keifer) was identified as the vector of the virus and caused persistent infection of barley (Hordeum vulgare L.) and wheat (Triticum aestivum L.) in greenhouse experiments. The …

Center For Grassland Studies Newsletter, Fall 1997, Volume 3, No. 4

Center for Grassland Studies: Newsletters

Contents:

The Nebraska Gap Analysis Project: Geographic Information for Land Resource Managers by Marlen Eve and James Merchant, Conservation and Survey Division, University of Nebraska-Lincoln

1998 Nebraska Range Shortcourse by Lowell Moser, Department of Agronomy, University of Nebraska-Lincoln

The Konza Prairie: Our Tallgrass Neighbors by Rob Peters, formerly with The Land Institute, Salina, Kansas

Festival of Color Draws 9,000 This Year

Conservation Compliance Credit For Winter Wheat Fall Biomass Production And Implications For Grain Yield, Gregory S. Mcmaster, Wallace Wilhelm

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

Producers participating in federal farm and conservation programs must reduce potential erodibility below certain thresholds on lands classified as highly erodible. The Natural Resource Conservation Service (NRCS) will credit producer s in Colorado for the quantity of green winter wheat (Triticum aestivum L.) biomass at the beginning of the winter period towards compliance in reducing erosion. Unfortunately, few data exist on fall winter wheat biomass production and fall production varies widely based on many site-specific factors at planting and during the fall, and can be expensive to document. To address these problems, a crop simulation model called SHOOTGRO …

Predicting Developmental Morphology In Switchgrass And Big Bluestem, Rob B. Mitchell, Kenneth J. Moore, Lowell E. Moser, John O. Fritz, Daren D. Redfearn

Department of Agronomy and Horticulture: Faculty Publications

Switchgrass (Panicum virgatum L.) and big bluestem (Andropogon gerardii Vitman) are important warm-season grasses in livestock production systems in the central and eastern USA. The objectives of this study were to quantify the morphological development of ‘trailblazer’ switchgrass and 'Pawnee' big bluestem and to evaluate day of the year (DOY) and growing degree day (GDD) as predictors of switchgrass and big blnestem morphological stage. Pure stands of each species were sampled at weekly intervals in 1990 and 1991 at Mead, NE, and classified as to mean stage count (MSC) and mean stage weight (MSW). Prediction equations for MSC …

The Prairie Naturalist Volume 29, No.3. September 1997

The Prairie Naturalist

FISHING STATISTICS IN KANSAS PUT-AND-TAKE RAINBOW TROUT FISHERIES ▪ R. D. Schultz and D. D. Nygren

DISTRIBUTIONAL STATUS Of UNCOMMON FISHES AND AN AMPHIBIAN FROM NORTHEASTERN MISSOURI ▪ R. A. Hrabik,

DIET OF A RELICT POPULATION OF THE EASTERN WOODRAT IN NEBRASKA ▪ H. H. Genoways, P. W Freeman, and M. K. Clausen

ANIMAL SPECIES MONITORED BY THE SOUTH DAKOTA NATURAL HERITAGE PROGRAM ▪ E. D. Stukel and D. C. Backlund

Dedication

Announcements

Asymbiotic In Vitro Seed Germination, Micropropagation And Scanning Electron Microscopy Of Several Temperate Terrestrial Orchids (Orchidaceae), Erika Szendrák

Department of Agronomy and Horticulture: Dissertations, Theses, and Student Research

Twenty-five different orchid species were successfully asymbiotically germinated and raised on a modified FAST medium (Fast 1976; Szendrák and R Eszéki, 1993). The development of geminating protocorms and young plantlets were recorded and compared among species. Spontaneous vegetative proliferation was also observed. Natural dispersed daylight and prevailing day-length were more favorable than l6-hour cool white fluorescent light for plantlet development. After two to three years of culture, the young plants were suitable for transfer ex vitro.

The effects of organic compounds most commonly used for orchid micropropagation (peptone, coconut water, casein+lactalbumin and glucose) and medium consistencies were investigated for …

Center For Grassland Studies Newsletter, Summer 1997, Volume 3, No. 3

Center for Grassland Studies: Newsletters

Contents:

New Conservation Reserve Program Under 1996 Farm Bill by Craig Derickson, USDA, Natural Resources Conservation Service

Plant Materials Centers Develop Plants to Solve Conservation Problems by Pam Murray, Coordinator, Center for Grassland Studies

CGS Advisory Council Tours South Central Nebraska

UNL Management Intensive Grazing Program Has $3 Million Impact

TGIF Doesn't Always Mean "Thank Goodness It's Friday"

Stop By Crane Meadows Nature Center On Next Flight Down I-80

Characteristics Of Beet Soilborne Mosaic Virus, A Furo-Like Virus Infecting Sugar Beet, G.B. Heidel, C.M. Rush, T.L. Kendall, S.A. Lommel, Roy C. French

Department of Plant Pathology: Faculty Publications

Beet soilborne mosaic virus (BSBMV) is a rigid rod-shaped virus transmitted by Polymyxa betae. Particles were 19 nm wide and ranged from 50 to over 400 nm, but no consistent modal lengths could be determined. Nucleic acids extracted from virions were polyadenylated and typically separated into three or four discrete bands of variable size by agarose-formaldehyde gel electrophoresis. RNA 1 and 2, the largest of the RNAs, consistently averaged 6.7 and 4.6 kb, respectively. The sizes and number of smaller RNA species were variable. The molecular mass of the capsid protein of BSBMV was estimated to be 22.5 kDa. …

Epigenetic Silencing Of A Foreign Gene In Nuclear Transformants Of Chlamydomonas, Heriberto D. Cerutti, Anita M. Johnson, Nicholas W. Gillham, John E. Boynton

Center for Plant Science Innovation: Faculty and Staff Publications

The unstable expression of introduced genes poses a serious problem for the application of transgenic technology in plants. In transformants of the unicellular green alga Chlamydomonas reinhardtii, expression of a eubacterial aadA gene, conferring spectinomycin resistance, is transcriptionally suppressed by a reversible epigenetic mechanism(s). Variations in the size and frequency of colonies surviving on different concentrations of spectinomycin as well as the levels of transcriptional activity of the introduced transgene(s) suggest the existence of intermediate expression states in genetically identical cells. Gene silencing does not correlate with methylation of the integrated DNA and does not involve large alterations in its …

Proceedings Of The Global Conference On Ergot Of Sorghum, Carlos R. Casela, Jeffery A. Dahlberg

INTSORMIL Impacts and Bulletins

In June 1996, several of us had the opportunity to see sorghum ergot in Brazil and the damage that the disease can do. We saw severe damage in seed production plots and witnessed the pain that seed producers had to go through to deal with this new problem. There was a wide spread scare in the sorghum community in the Americas because of the infamous reputation of the disease in causing damage in seed production fields. As a silver lining, we also observed first hand, the excellent research program that the Brazilians had in place. It became apparent that all …

Relationships Between In Situ Protein Degradability And Grass Developmental Morphology, R. B. Mitchell, D. D. Redfearn, Lowell E. Moser, R. J. Grant, K. J. Moore, B. H. Kirch

Department of Agronomy and Horticulture: Faculty Publications

The objective of this research was to determine the relationships between the morphological development and in situ ruminally degradable protein (RDP), ruminally undegradable protein (RUP), and microbial protein of two cool season grasses (intermediate wheatgrass and smooth bromegrass) and two warm season grasses (switchgrass and big bluestem). The initial growth of grass tillers grown near Mead, Nebraska was clipped at ground level six times during the 1992 growing season and morphologically classified. Mean stage was calculated. Forage was ground to pass a 2-mm screen and was incubated in ruminally fistulated steers for 16 h. The RUP was adjusted for microbial …

The Aspergillus Nidulans Sepa Gene Encodes An Fh1/2 Protein Involved In Cytokinesis And The Maintenance Of Cellular Polarity, Steven D. Harris, Lisbeth Hamer, Kathryn E. Sharpless, John E. Hamer

Department of Plant Pathology: Faculty Publications

Cytokinesis (septation) in the fungus Aspergillus nidulans occurs through the formation of a transient actin ring at the incipient division site. Temperature-sensitive mutations in the sepA gene prevent septation and cause defects in the maintenance of cellular polarity, without affecting growth and nuclear division. The sepA gene encodes a member of the growing family of FH1/2 proteins, which appear to have roles in morphogenesis and cytokinesis in organisms such as yeast and Drosophila Results from temperature shift and immunofluorescence microscopy experiments strongly suggest that sepA function requires a preceding mitosis and that sepA acts prior to actin ring formation. Deletion …

The Prairie Naturalist Volume 29, No.2. June 1997

The Prairie Naturalist

CHRISTMAS BIRD COUNTS FOR NORTH DAKOTA - 1996 ▪ . R. N. Randall

BREEDING BIRD RICHNESS IN THE PRAIRIE POTHOLE REGION OF MINNESOTA ▪ . S. L. Niesar and D. E. Hubbard

UNUSUAL MIGRATION BY A WHITE-TAILED DEER FAWN IN SOUTH DAKOTA ▪ C. S. DePerno, S. L. Griffin, J. A. Jenks, and L. A. Rice

COYOTE FOOD HABITS AT DESOTO NATIONAL WILDLIFE REFUGE, NEBRASKA ▪ J. J. Huebschman, S. E. Hygnstrom, and J. A. Gubanyi

WHITE BASS GROWTH IN SOUTH DAKOTA WATERS ▪ D. W. Willis, H. D. Beck, C. A. Soupir, B. A. Johnson, G. D. Simpson, and …

United States Patent, Number: 5,633,447: Plant Tissue Comprising A Subgenomic Promoter, Paul G. Ahlquist, Roy C. French

Department of Plant Pathology: Faculty Publications

A subgenomic promoter of a positive strand RNA virus is disclosed which directs the amplified expression of a structural gene in plant tissue. The core region and an upstream activating domain of the subgenomic promoter are identified. This promoter can be utilized in a modified virus. or in an appropriate engineered recombinant DNA derivative which may be chromosomally integrated or maintained as an episome in transformed cells.

Pathogenicity Of Escherichia Coli O157:H7 In The Intestines Of Neonatal Calves, Evelyn A. Dean-Nystrom, Brad T. Bosworth, William C. Cray Jr., Harley W. Moon

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

Cattle are an important reservoir of Shiga toxin-producing enterohemorrhagic Escherichia coli (EHEC) O157:H7 strains, foodborne pathogens that cause hemorrhagic colitis and hemolytic uremic syndrome in humans. EHEC O157:H7 strains are not pathogenic in calves >3 weeks old. Our objective was to determine if EHEC O157:H7 strains are pathogenic in neonatal calves. Calves(A/E) lesions in both the large and small intestines by 18 h postinoculation. The severity of diarrhea and inflammation, and also the frequency and extent of A/E lesions, increased by 3 days postinoculation. We conclude that EHEC O157:H7 strains are pathogenic in neonatal calves. The neonatal calf model is …

Review Of Retracing Major Stephen H. Long's Expedition: The Itinerary And Botany By George J. Goodman And Cheryl A. Lawson, Robert B. Kaul

Great Plains Research: A Journal of Natural and Social Sciences

Earlier expeditions made incidental collections of plants and animals in Louisiana Territory, but the Long Expedition of 1820 was the first deliberately staffed with scientists assigned to that task. Authorized by President Monroe and Secretary of War Calhoun, the Expedition was directed to document plant and animal life and geology in the intimidating country between the Missouri River and the Rocky Mountains and to find the source of the Platte and Red Rivers in the mountains. All this was to be done quickly and, in fact, took only 100 days, June 6-September 13, 1820. Starting near present-day Omaha, the Expedition …

Chlorella Virus Pbcv-1 Encodes A Homolog Of The Bacteriophage T4 Uv Damage Repair Gene Denv, Masakazu Furuta, John Schrader, Holly Schrader, Tyler Kokjohn, Simon Nyaga, Amanda Mccullough, R. Stephen Lloyd, Dwight Burbank, Dorit Landstein, Leslie C. Lane, James L. Van Etten

Department of Plant Pathology: Faculty Publications

The bacteriophage T4 denV gene encodes a well-characterized DNA repair enzyme involved in pyrimidine photodimer excision. We have discovered the first homologs of the denV gene in chlorella viruses, which are common in fresh water. This gene functions in vivo and also when cloned in Escherichia coli. Photo-damaged virus DNA can also be photoreactivated by the host chlorella. Since the chlorella viruses are continually exposed to solar radiation in their native environments, two separate DNA repair systems, one that functions in the dark and one that functions in the light, significantly enhance their survival.

Comparison Of Avrd Alleles From Pseudomonas Syringae Pv. Glycinea, Lisa Wolfson Keith, Carol Boyd, Noel T. Keen, J. E. Patridge

Department of Plant Pathology: Faculty Publications

Avirulence gene D alleles resided on indigenous plasmids in races 0, 2, 3, 4, 5, and 6 of Pseudomonas syringae pv. glycinea (Psg), but the allele in race 1 appeared to be chromosomal. These were all nonfunctional avirulence genes because they neither induced the avirulence phenotype on Rpg4 soybean cultivars nor directed the production of syringolide elicitors when expressed in Escherichia coli cells. The predicted proteins encoded by the seven Psg avrD genes were very similar to that of a functional class II allele from P. syringae pv. phaseolicola G50 race 2, but contained mutations collectively …

Center For Grassland Studies Newsletter, Spring 1997, Volume 3, No. 2

Center for Grassland Studies: Newsletters

Contents:

Environmental Quality Incentives Program by Dayle Williamson, Nebraska Natural Resources Commission

High Quality Seed: Importance for Grasslands by Roger Hammons, Nebraska Crop Improvement Association

Management Intensive Grazing Basics by Steven Melvin, Extension Educator, UNL

Rangeland Grasshoppers of Nebraska by John B. Campbell and Gary Hein West Central and Panhandle Research & Extension Centers, UNL

Pastured Poultry Organization Formed

Eastern Gamagrass: Forage and A Whole Lot More

Public Input Sought on Grassland and Forest Plans

Characterization Of An Atp-Dependent Dna Ligase Encoded By Chlorella Virus Pbcv-1, C. Kiong Ho, James L. Van Etten, Stewart Shuman

Department of Plant Pathology: Faculty Publications

We report that Chlorella virus PBCV-1 encodes a 298-amino-acid ATP-dependent DNA ligase. The PBCV-1 enzyme is the smallest member of the covalent nucleotidyl transferase superfamily, which includes the ATP-dependent polynucleotide ligases and the GTP-dependent RNA capping enzymes. The specificity of PBCV-1 DNA ligase was investigated by using purified recombinant protein. The enzyme catalyzed efficient strand joining on a singly nicked DNA in the presence of magnesium and ATP (K_m, 75 μM). Other nucleoside triphosphates or deoxynucleoside triphosphates could not substitute for ATP. PBCV-1 ligase was unable to ligate across a 2-nucleotide gap and ligated poorly across a 1-nucleotide …

Proceedings Of The 24th Annual Meeting, Southern Soybean Disease Workers (March 15-16, 1997, Fort Walton Beach, Florida), Robert P. Mulrooney, Gabe Sciumbato, Steve Koenning, John Russin, Glenn G. Hammes

Southern Soybean Disease Workers: Conference Proceedings

Contents

Business session

Soybean Disease Loss Estimate for the Southern United States during 1996. Compiled by PW Pratt

Treasurer report. GG Hammes

SSDW Committee chairmen for 1996-1997

Graduate student papers

Characterization of Races of Phytophthora sojae in Arkansas and Their Effects on Commonly Grown Cultivars. TA Jackson, TL Kirkpatrick, and JC Rupe

Induction of Defense Related Proteins During Compatible and Incompatible Soybean-Cercospora sojina Interactions. WA Baker, J Qiu, CB Lawrence, S Tuzun, and DB Weaver

Contributed papers

Performance and Cyst Nematode Resistance of Selected Soybean Cultivars in North Carolina Production Fields. SR Koenning and KR Barker

Distribution and Diversity …

Leaf Nutritive Value Related To Tiller Development In Warm-Season Grasses, J. R. Hendrickson, Lowell E. Moser, K. J. Moore, Steven S. Waller

Department of Agronomy and Horticulture: Faculty Publications

Assessing nutritive value of key grass species in relation to plant development is essential for producers to efficiently manage livestock enterprises. Changes in nutritive value for tiller populations of 2 common Nebraska Sandhills grasses, prairie sandreed [Calamovilfa longifolia (Hook.) Scribn.] and sand bluestem [Andropogon gerardii var. paucipilus (Nash) Fern.], in response to morphological development was evaluated at the Gudmundsen Sandhills Laboratory (GSL) during the 1990 and 1991 growing seasons. Morphological development was determined on a 40 to 60-tiller sample from each block (12 blocks in 1990 and 8 blocks in 1991) at ten-day intervals using a comprehensive staging …

The Prairie Naturalist Volume 29, No.1. March 1997

The Prairie Naturalist

UPDATED DISTRIBUTION OF THE LEAST WEASEL ON THE CENTRAL GREAT PLAINS ▪ S. R. Hoofer and J. R. Choate

ESTIMATING SURVIVAL OF SONG BIRD CARCASSES IN CROPS AND WOODLOTS ▪ G. M. Linz, D. L. Bergman, and W. J. Bleier

SEXUAL ALLOCATION IN Carex stricta, A MONOECIOUS, TUSSOCK-FORMING SEDGE ▪ D. M. Estrella and C. E. Umbanhowar, Jr.

ABUNDANCE OF THIRTEEN-LINED GROUND SQUIRRELS IN SHORTGRASS PRAIRIE ▪ L. C. Higgins and P. Stapp

BATS OF JEWEL CAVE NATIONAL MONUMENT, SOUTH DAKOTA ▪ J. R. Choate and J. M. Anderson

NOTES

Northern Harrier Builds Nest On Top Of Depredated Mallard …

United States Patent , Number: 5,602,242: Hybrid Rna Virus, Paul G. Ahlquist, Roy C. French, Robert F. Sacher

Department of Plant Pathology: Faculty Publications

A recombinant RNA virus is provided allowing encapsidation of genetically engineered viral sequences in heterologous, preferably rod-shaped coat, protein capsids. Since icosahedral viruses are limited in the amount of RNA they can carry, and rod-shaped viruses are expansible, this invention allows the size of recombinant virus RNA components to be increased (or decreased). Methods of making and using such recombinant viruses are also provided, specifically with respect to the transfection of plants to bring about genotypic and phenotypic changes.