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Effects Of Breed Group By Location Interaction On Crossbred Cattle In Nebraska And Florida, T. A. Olson, K. Euclides Filho, L. V. Cundiff, M. Koger, W. T. Butts Jr., K. E. Gregory Jan 1991

Effects Of Breed Group By Location Interaction On Crossbred Cattle In Nebraska And Florida, T. A. Olson, K. Euclides Filho, L. V. Cundiff, M. Koger, W. T. Butts Jr., K. E. Gregory

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

Data on 2,744 calves produced in Clay Center, Nebraska, and Brooksville, Florida, were used to evaluate the importance of genotype × location interactions on the reproductive and maternal performance of eight breed groups of F1 crossbred cows. A total of 648 F1 crossbred cows included Bos taurus × Bos taurus (Bt × Bt) crosses: Hereford × Angus reciprocal crossbreds (HA and AH), Pinzgauer × Angus (PA), Pinzgauer × Hereford (PH); and Bos indicus× Bos taurus (Bi × Bt) crosses: Brahman × Angus (BA), Brahman × Hereford (BH), Sahiwal × Angus (SA) and Sahiwal × Hereford (SH). The first calf …


Size Differences Among Root-Knot Nematodes On Resistant And Susceptible Alyceclover Genotypes, L. E. Powers, R. A. Dunn, R. Mcsorley Jan 1991

Size Differences Among Root-Knot Nematodes On Resistant And Susceptible Alyceclover Genotypes, L. E. Powers, R. A. Dunn, R. Mcsorley

Department of Plant Pathology: Faculty Publications

The influence of plant resistance on the size of individual root-knot nematodes was determined in greenhouse experiments. Five genotypes of alyceclover were inoculated with second-stage juveniles of Meloidogyne incognita race 3 or M. arenaria race 1. Plants were harvested at selected intervals and stained for detection of the nematodes, which were dissected from the roots. Length, width, and sagittal-sectional area of each animal were measured using an image-analysis system, and areas of nematodes in all stages were compared at different times and across alyceclover lines. Nematodes feeding on roots of resistant lines were consistently smaller than those on susceptible plants, …


Inheritance Of Acid-Soil Tolerance In Sorghum (Sorghum Bicolor) Grown On An Ultisol, C. I. Flores, L. M. Gourley, Jeffrey F. Pedersen, R. B. Clark Jan 1991

Inheritance Of Acid-Soil Tolerance In Sorghum (Sorghum Bicolor) Grown On An Ultisol, C. I. Flores, L. M. Gourley, Jeffrey F. Pedersen, R. B. Clark

Department of Agronomy and Horticulture: Faculty Publications

Inheritance of acid-soil tolerance (generally considered AI-toxicity tolerance) i.n sorghum [Sorghum bicolor (L.) Moench] is not clear. Forty F1 sorghum hybrids and their 14 parents were grown two seasons in the field at relatively high (67 and 71%) and low (43 and 42%) Al saturations on an acid Ultisol in Colombia, South America to evaluate the effects of acid soil on agronomic component traits and to better understand inheritance of acid-soil tolerance of sorghum. For plants grown at the high Al saturation levels, hybrids from acid-soil tolerant [AS-T] x acid soil-sensitive [AS-S] crosses were as tolerant as hybrids from …


Fertility And Forage Yield Of Sorghum X Sudangrass Hybrids In A1 And A3 Cytoplasm, J. J. Toy, Jeffrey F. Pedersen, K. J. Moore Jan 1991

Fertility And Forage Yield Of Sorghum X Sudangrass Hybrids In A1 And A3 Cytoplasm, J. J. Toy, Jeffrey F. Pedersen, K. J. Moore

Department of Agronomy and Horticulture: Faculty Publications

Most sorghum x sudangrass hybrids are currently produced in Al male-sterile cytoplasm. Availability of alternative cytoplasmic sterility systems allows production of sorghum x sudangrass hybrids that may have superior forage characteristics. A study was conducted to compare the agronomic performance of Al and A3 sorghum x sudangrass hybrids. A bulk of eight sudangrass populations was used to pollinate four grain sorghum inbreds normally used as females that had been sterilized in both Al and A3 cytoplasm, and two inbreds normally used as males that had been sterilized in A3 cytoplasm. The hybrids were evaluated in 1990. Results indicate that male-sterile …


Notes: Interpretive Analysis For Forage Yield Trial Data, Jeffrey F. Pedersen, K. J. Moore, Edzard Van Santen Jan 1991

Notes: Interpretive Analysis For Forage Yield Trial Data, Jeffrey F. Pedersen, K. J. Moore, Edzard Van Santen

Department of Agronomy and Horticulture: Faculty Publications

Forage cultivar evaluation is often done in small plots with multiple harvests throughout the growing season. Data is often summarized by presenting a yearly total yield for each cultivar in addition to the mean for each harvest date. Data summarization often becomes burdensome and difficult to interpret. Regressing yield against a growth index associated with harvest dates can be utilized to describe forage performance in a concise and easily interpreted format. Subsets of data from tall fescue (Festuca amndinacea Schreb.) yield trials conducted in Alabama and Kentucky were used to demonstrate the technique. The analysis involves regressing yield of a …


Nitrogen And Methyl Jasmonate Induction Of Soybean Vegetative Storage Protein Genes, Paul E. Staswick, Jing-Feng Huang, Yoon Rhee Jan 1991

Nitrogen And Methyl Jasmonate Induction Of Soybean Vegetative Storage Protein Genes, Paul E. Staswick, Jing-Feng Huang, Yoon Rhee

Department of Agronomy and Horticulture: Faculty Publications

Vegetative storage protein (VSP) and VSP mRNA levels in soybean (Glycine max) leaves correlated with the amount of NH4NO3 provided to nonnodulated plants. The mRNA level declined as leaves matured, but high levels of N delayed the decline. This is consistent with the proposed role for VSP in the temporary storage of N. Wounding, petiole girdling, and treatment with methyijasmonate (MeJA) increased VSP mRNA in leaves 24 hours after treatment. The magnitude of the response depended on leaf age and N availability. N deficiency essentially eliminated the response to wounding and petiole girdling. MeJA was …


Sterol Composition Of The Corn Root Lesion Nematode, Pratylenchus Agilis, And Corn Root Cultures, David J. Chitwood, William R. Lusby Jan 1991

Sterol Composition Of The Corn Root Lesion Nematode, Pratylenchus Agilis, And Corn Root Cultures, David J. Chitwood, William R. Lusby

Harold W. Manter Laboratory of Parasitology: Faculty Publications

Sterols from mixed stages of the com root lesion nematode, Pratylenchus agilis, and uninfected corn root cultures were analyzed by gas chromatography-mass spectrometry. Twenty-eight sterols were identified in P. agilis, including nine not previously detected in nematodes. The major sterols were 24-ethylcholest-22-enol, 24-ethylcholesta-5,22-dienol, 24-methy1cholestanol, 24-ethylcholestanol, isofucostanol, and 24-ethylcholesterol. The principal corn root sterols were 24-ethylcholesta-5,22-dienol, 24-methylcholesterol, 24-ethylcholesterol, isofucosterol, and cycloartenol. Therefore, the major metabolic transformation of sterols by P. agilis was saturation of the sterol nucleus. In addition, very small amounts of 4α-methylsterols were biosynthesized by P. agilis. The 4-methylation pathway is unique to nematodes and was …


Origin And Evolution Of Defective Interfering Rnas Of Tomato Bushy Stunt Virus, David A. Knorr, Thomas Jack Morris Jan 1991

Origin And Evolution Of Defective Interfering Rnas Of Tomato Bushy Stunt Virus, David A. Knorr, Thomas Jack Morris

School of Biological Sciences: Faculty Publications

Viruses with defective genomes have been identified in association with virtually every major family of viruses and have been widely utilized as tools for investigating virus functions in animal cell culture systems (Perrault, 1981). It is generally thought that defective interfering viruses (DIs) arise through deletion, rearrangement, or recombination of a competent viral genome. DIs tack the ability for independent existence relying on their parental helper viruses to supply factors required for replication, maturation, and/or encapsidation (Huang and Baltimore, 1977). The interference attributed to DIs is thought to result from competition with the helper virus for factors required in trans …


The Effect Of Various Plant Growth Regulators On Rough Turf At Coles County Airport, Jay C. A. Harnack Jan 1991

The Effect Of Various Plant Growth Regulators On Rough Turf At Coles County Airport, Jay C. A. Harnack

Masters Theses

A field test was conducted to determine the effectiveness of various concentrations of selected plant growth regulators. All PGR's were applied at various rates and combinations on rough turf at Coles County Airport, Charleston, Illinois.

The dominant grasses in the test site were bluegrass (Poa pratensis Huds.) and fescue (Poa pratensis L.).

The plant growth regulators were evaluated at regular intervals for the reduction of biomass, reduction of height, seedhead suppression, and color relative to control.

One third ounce per acre Escort in combination with 4 ounces per acre Embark was the most effective in reducing biomass accumulation followed by …


The Bryophytes Of Knox County, Illinois, Kurtis J. Cecil Jan 1991

The Bryophytes Of Knox County, Illinois, Kurtis J. Cecil

Masters Theses

Field and herbarium studies conducted over an eleven month period found 84 taxa of bryophytes in Knox County. Included in this list are one hornwort (Class Anthocerotae), 15 liverworts (Class Hepaticae), and 68 mosses (Class Musci). Eighty-two species are new county records. Six previously unreported taxa produced during herbarium studies and one previous report were not relocated in the field. An annotated list provides collection data, location of voucher, and frequency of those species located in Knox County. A presettlement vegetation map is included to illustrate the location of collection sites.


Woody Plants Of The Lower Rio Grande Valley, Texas, Robert I. Lonard, James H. Everitt, Frank W. Judd Jan 1991

Woody Plants Of The Lower Rio Grande Valley, Texas, Robert I. Lonard, James H. Everitt, Frank W. Judd

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

Description of Common Vegetation of Lower Rio Grande Valley.


Multivariate Analysis Of The Carex Brevior Group In Iowa, Scott C. Zager Jan 1991

Multivariate Analysis Of The Carex Brevior Group In Iowa, Scott C. Zager

Dissertations and Theses @ UNI

In Iowa, the most troublesome sedges to identify are Carex brevior, C. festucacea, C. molesta, C. normalis, C. tenera, and C. tenera var. echinodes. These taxa form the C. brevior group--part of an even larger aggregate of species associated with C. straminea. Their morphological features are indistinct and intergrade into one another. Botanists have had difficulty classifying members of this aggregate for nearly 200 years. Some authors have viewed the taxa as separate species, others as polymorphic forms of a single species. Much of the contention has centered upon the variation of taxonomic characters used to delimit and distinguish species. …


The Distribution And Reproductive Phenology Of The Milkweeds (Asclepiadaceae: Asclepias And Cynanchum) In Nebraska, Robert B. Kaul, Steven B. Rolfsmeier, Jeffrey J. Esch Jan 1991

The Distribution And Reproductive Phenology Of The Milkweeds (Asclepiadaceae: Asclepias And Cynanchum) In Nebraska, Robert B. Kaul, Steven B. Rolfsmeier, Jeffrey J. Esch

Transactions of the Nebraska Academy of Sciences and Affiliated Societies

The Asclepiadaceae are represented in Nebraska by seventeen native species of Asclepias and one of Cynanchum. Two species are here added to the State's flora: Asclepias asperula and A. purpurascens. Detailed county distribution maps are presented for all species based upon our extensive field and herbarium work, and numerous additions and corrections are made to the maps published in the Atlas of the Flora of the Great Plains in 1977. A map is presented showing the zone of hybridization of A. speciosa with A. syriaca in central Nebraska. Data are given on flowering and fruiting phenology for each …


New And Corrected Floristic Records For Nebraska, Steven B. Rolfsmeier, Robert B. Kaul, David M. Sutherland Jan 1991

New And Corrected Floristic Records For Nebraska, Steven B. Rolfsmeier, Robert B. Kaul, David M. Sutherland

Transactions of the Nebraska Academy of Sciences and Affiliated Societies

Nineteen species (including eight Eurasian ones) are newly recorded for Nebraska: Alopecurus arundinaceus, Amaranthus californicus, Asclepias asperula, A. purpurascens, Cardamine {lexuosa*, Centaurea diffusa, Dipsacus laciniatus, Eriochloa villosa, Euclidium syriacum, Gentiana alba, Geranium viscosissimum, Geum vernum, Goodyera oblongifolia, Haplopappus multicaulis, Heterotheca latifolia, Lathyrus tuberosus, Polygonum douglasii, Scirpus saximontanus, Veronica biloba. Twenty-one others are shown to be more widespread in Nebraska than previously known, one has a more restricted range than previously reported, two (Scirpus smithii, S. torreyi) are deleted from the flora based upon corrected identifications, and the status of some rarely-collected species is updated. Thirty-two additions, two …


The Western Kentucky University Horticultural Gardens: A Design & Implementation Plan, Catharine Schriver Dec 1990

The Western Kentucky University Horticultural Gardens: A Design & Implementation Plan, Catharine Schriver

Masters Theses & Specialist Projects

The purpose of this thesis was to design a master landscape plan rnd serve as a preliminary planning tool for the development of Horticulture Gardens at Western Kentucky University. The planning process involved the development of a mission statement and goals for the gardens, analysis of the site, and design of a landscape plan for the proposed six acre Horticultural Gardens located at the WKU farm. Other areas related to the Garden's development explored in the thesis include: an outline of course learning objectives that could be achieved through learning activities conducted at the Horticultural Gardens, an examination of ways …


Nebline, December 1990 Dec 1990

Nebline, December 1990

NEBLINE Newsletter Archive from Nebraska Extension in Lancaster County

Ag Update: Agricultural News & Events

Home Extension News

On-the-Grow: Horticulture News & Recommendations

The Cloverline: 4-H News and Events

Extension Calendar

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The Prairie Naturalist Volume 22, No. 4. December 1990 Dec 1990

The Prairie Naturalist Volume 22, No. 4. December 1990

The Prairie Naturalist

Paul B. Kannowski, Editor

Nikki R. Seabloom, Assistant Editor

Douglas H. Johnson, Book Review Editor

CONTENTS

DISTRIBUTION AND STATUS OF GREATER PRAIRIE-CHICKENS IN COLORADO ▪ B. F. Van Sant and C. E. Braun

IMPORTANCE OF AN OLD, MULTIPLE-USE RESERVOIR TO MIGRATING AND WINTERING DABBLING DUCKS ▪ D. M. Leslie, Jr. , and W. J. Stancill

SIMILARITY OF MALLARD NESTING ON A SOUTH DAKOTA ISLAND BETWEEN 1967-68 and 1985-87 ▪ S. G. Simpson and D. Limmer

BOBCAT HABITAT USE IN SOUTHEASTERN MONTANA DURING PERIODS OF HIGH AND LOW LAGOMORPH ABUNDANCE ▪ B. J. Giddings, G. L. Risdahl, and L. R. Irby …


Risk-Based Oversight Of Experiments In The Environment, Henry I. Miller, Robert H. Burris, Anne K. Vidaver, Nelson A. Wivel Oct 1990

Risk-Based Oversight Of Experiments In The Environment, Henry I. Miller, Robert H. Burris, Anne K. Vidaver, Nelson A. Wivel

Department of Plant Pathology: Faculty Publications

The new biology has come of age. Basic research in fields ranging from immunology to plant biology has been transformed so as to be almost unrecognizable to those whose biology education ended before 1970. The spillover into commercial development likewise has been remarkable. Hardly a week passes without news of some new advance in an area such as therapeutics, vaccines, or plants and animals for food, feed, or fiber. These uses of biotechnology in "contained" laboratories, pilot plants, greenhouses, and production facilities have engendered little controversy. The National Institutes of Health Guidelines for Research Involving Recombinant DNA have exempted from …


Root Biomass And Production In Four Communities Within The Great Dismal Swamp, Susan West Powell Oct 1990

Root Biomass And Production In Four Communities Within The Great Dismal Swamp, Susan West Powell

Biological Sciences Theses & Dissertations

A biomass difference approach was used to measure biomass and production over eleven months in four different communities within the Great Dismal Swamp. On all sites, fine roots were the moat dynamic root component. Both biomass and production were highest on the mixed hardwood site, the least flooded site, and second highest on the cedar site, the site with the longest duration of saturation. The maple-gum and cypress sites had lower amounts of biomass and rates of production. Environmental parameters that influenced production included frequency and duration of flooding, density of the stand, and soil type.

A second method, an …


Notes On Neotropical Amanoa (Euphorbiaceae), W. John Hayden Oct 1990

Notes On Neotropical Amanoa (Euphorbiaceae), W. John Hayden

Biology Faculty Publications

Lectotypes are designated for Amanoa caribaea Krug & Urban and A. guianensis Aublet; presumed syntypes of the latter taxon are shown to be heterogeneous by inclusion of a previously unrecognized species. Four new species of Amanoa are described: A. congesta from French Guiana and northeastern Brazil; A. gracillima from Manaus, Brazil; A. nanayensis from Amazonian Peru and adjacent Colombia and Brazil; and A. neglecta from French Guiana and Surinam. Amanoa sinuosa is proposed as a new name for the later homonym A. robusta Leal. A key to the 13 neotropical species is presented.


Nebline, September 1990 Sep 1990

Nebline, September 1990

NEBLINE Newsletter Archive from Nebraska Extension in Lancaster County

Ag Update: Agricultural News & Events

Home Extension News

On-the-Grow: Horticulture News & Recommendations

The Cloverline: 4-H News and Events

Extension Calendar

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The Prairie Naturalist Volume 22, No. 3. September 1990 Sep 1990

The Prairie Naturalist Volume 22, No. 3. September 1990

The Prairie Naturalist

Paul B. Kannowski, Editor

Nikki R. Seabloom, Assistant Editor

Douglas H. Johnson, Book Review Editor

CONTENTS

ASSEMBLAGES OF SMALL FISH IN THREE HABITAT TYPES ALONG THE PLATTE RIVER, NEBRASKA ▪ D. T. O'Shea, W. A. Hubert, and S. H. Anderson

SPAWNING HABITAT OF CHANNEL CATFISH IN THE POWDER RIVER SYSTEM, WYOMING-MONTANA D. R. Gerhardt and W. A. Hubert

OCCURRENCE OF AMERICAN WHITE PELICANS ALONG THE PLATTE RIVER, NEBRASKA ▪ J. G. Sidle, C. A. Faanes, and W. G. Jobman

DIET OF CANVASBACKS DURING BREEDING ▪ J. E. Austin, J. R. Serie, and J. H. Noyes

BROOD HABITAT USE OF RIO …


Ermelo Weeping Lovegrass Response To Clipping, Fertilization, And Watering, Robert A. Masters, Carlton Britton Sep 1990

Ermelo Weeping Lovegrass Response To Clipping, Fertilization, And Watering, Robert A. Masters, Carlton Britton

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

A management strategy using short-duration grazing and fertilization was simulated in a study with individual 'Ermelo' weeping lovegrass [Eragrostis curvula (Shrad.)Nees] plants. Influence of 2 levels of clipping [unclipped during the growing season and clipped (C) to 10-cm stubble height each time regrowth reached 40 cm]; fertilizer [unfertilized and 70-34-44 kg N-P-K/ha (F)]; and watering frequency [irrigated to field capacity at 7- (WET) and 14- (DRY) day intervals] on cumulative herbage dry matter yield, crude protein yield, and water-use efficiency, and root mass of individual weeping lovegrass plants grown in soil contained in polyethylene tubes was determined. Clipping combined …


Nebline, August 1990 Aug 1990

Nebline, August 1990

NEBLINE Newsletter Archive from Nebraska Extension in Lancaster County

Ag Update: Agricultural News & Events

Home Extension News

On-the-Grow: Horticulture News & Recommendations

The Cloverline: 4-H News and Events

Extension Calendar

and other extension news

Special Lancaster County Fair Insert


Life History Of Paracantha Gentilis (Diptera: Tephritidae), David H. Headrick, Richard D. Goeden Jul 1990

Life History Of Paracantha Gentilis (Diptera: Tephritidae), David H. Headrick, Richard D. Goeden

Horticulture and Crop Science

The life history of Paracantha gentilis Hering in southern California is described. This stenophagous tephritid reproduces in the capitula of native Cirsium thistles. Courtship and mating behavior are described from field and laboratory observations. Territorial and courtship behavior of males and the morphological characters involved in possible male pheromone emission are described and illustrated, as are the oviposition behavior and reproductive morphology of females. Egg clutch sizes ranged from one to 13 eggs, with a maximum of six clutches per capitulum. Larvae fed gregariously within stage-specific niches. Pupariation occurred in the capitula, from which adults emerged in mid-June through early …


Towards An Improved Taxonomy Of Xanthomonas, L. Vauterin, J. Swings, K. Kersters, M. Gillis, T. W. Mew, M. N. Schroth, N. J. Palleroni, D. C. Hildebrand, D. E. Stead, E. L. Civerolo, A. C. Hayward, H. Maraîte, R. E. Stall, A. K. Vidaver, J. F. Bradbury Jul 1990

Towards An Improved Taxonomy Of Xanthomonas, L. Vauterin, J. Swings, K. Kersters, M. Gillis, T. W. Mew, M. N. Schroth, N. J. Palleroni, D. C. Hildebrand, D. E. Stead, E. L. Civerolo, A. C. Hayward, H. Maraîte, R. E. Stall, A. K. Vidaver, J. F. Bradbury

Department of Plant Pathology: Faculty Publications

Improvement of the taxonomy of the genus Xanthomonas and especially of Xanthomonas campestris, which is subdivided into more than 125 pathovars, is discussed. Recent contributions to the taxonomy of Xanthomonas are reviewed, and on the basis of these data and unpublished data from several laboratories, the usefulness of different phenotypic, chemotaxonomic, and genotypic techniques is discussed. The heterogeneity of several X. campestris pathovars has been demonstrated by sodium dodecyl sulfate electrophoresis of whole-cell proteins and fatty acid fingerprinting. The host selectivity of the pathovars is not correlated with their relationships as revealed by DNA-DNA hybridization experiments. In order to …


An Autecological Study Of Pyxidanthera Barbulata In The Blackwater Ecologic Preserve Virginia, John Marc Lowenthal Jul 1990

An Autecological Study Of Pyxidanthera Barbulata In The Blackwater Ecologic Preserve Virginia, John Marc Lowenthal

Biological Sciences Theses & Dissertations

Pyxidanthera barbulata (pyxie moss), a rare and endangered subshrub, has been found in decreasing numbers in it's "pine barren" habitat. An autecological study encompassing vegetation association analysis and environmental measurements was performed in the Blackwater Ecologic Preserve, its only known location in Virginia. The preserve is being subjected to controlled burning and the effect of burning on the species was evaluated. A multivariate analysis of variance was performed to identify species associations, and simple analysis of variance was done to find trends in the environmental data. Four taxa were positively associated with P. barbulata, Gaultheria procumbens, Vaccinium tenellum, Cladonia spp., …


The Prairie Naturalist Volume 22, No. 2. June 1990 Jun 1990

The Prairie Naturalist Volume 22, No. 2. June 1990

The Prairie Naturalist

Paul B. Kannowski, Editor

Nikki R. Seabloom, Assistant Editor

Douglas H. Johnson, Book Review Editor

CONTENTS

BREEDING BIOLOGY OF THE BLACK-TAILED PRAIRIE DOG IN NORTH DAKOTA ▪ R. W. Seabloom and P. W. Theisen

PATTERNS OF RESOURCE USE IN A LIZZARD COMMUNITY IN THE NEBRASKA SAND HILLS PRAIRIE ▪ R. E. Ballinger, S. M. Jones, and J. W. Nietfeldt

A THIRTEEN-YEAR SURVEY OF THE APHIDOPHAGOUS INSECTS OF ALFALFA ▪ N. C. Elliott and R. W. Kieckhefer

STATUS AND DISTRIBUTION OF PLAINS SHARP-TAILED GROUSE IN COLORADO ▪ A. W. Hoag and C. E. Braun

CHRISTMAS BIRD COUNTS FOR NORTH DAKOTA - …


Capping Of Tobacco Mosaic Virus Rna: Analysis Of Viral-Coded Guanylyltransferase-Like Activity, David Dunigan, Milton Zaitlin May 1990

Capping Of Tobacco Mosaic Virus Rna: Analysis Of Viral-Coded Guanylyltransferase-Like Activity, David Dunigan, Milton Zaitlin

Department of Plant Pathology: Faculty Publications

The 5’ end of tobacco mosaic virus (TMV) genomic RNA is capped with 7- methylguanosine. A virus-coded polypeptide with guanylyltransferase activity has been investigated. This enzyme is responsible for forming the 5’→5’ linkage of guanosine 5’-monophosphate to the 5’- diphosphate of an acceptor RNA, thereby forming the cap. A critical step in the mechanism for cap formation in the eukaryotic nucleus is for guanylyltransferase to bind covalently to guanosine 5’- monophosphate with the hydrolysis of pyrophosphate when guanosine 5’- triphosphate is the substrate. The TMV 126-kilodalton protein, which is most probably a component of the TMV replicase, was found to …


The Short-Term Effects Of Manganese Toxicity On Ribulose 1,5 Biophosphate Carboxylase In Tobacco Chloroplasts, Kerrie Elliott May 1990

The Short-Term Effects Of Manganese Toxicity On Ribulose 1,5 Biophosphate Carboxylase In Tobacco Chloroplasts, Kerrie Elliott

Masters Theses & Specialist Projects

The short-term effects of manganese toxicity on ribulose 1,5 bisphosphate carboxylase (Rubisco) activity and concentration in tobacco chloroplasts were examined. The activity of the enzyme from both manganese-treated and control plants was determined 6, 12, 18, 24 , and 48 h after introduction of manganese (80 mg/Li. Enzyme activity was determined by monitoring rates of radioactive CO2 fixation into acid stable products. A slight stimulation of the enzyme's activity was noted in experimental plants after 18 h of exposure to manganese as compared with control plants. A decrease in the enzyme's activity in experimental plants was noted after 48 …