Digital Commons Network^™

The Plant Science Decadal Vision: Response To The Martin Commentary, David Stern, Sally Ann Mackenzie

Department of Agronomy and Horticulture: Faculty Publications

The plant science community is being called upon as never before to carry out research that addresses challenges in food, climate, and health, to educate a populace inundated with science misinformation, and to excite and recruit a new generation of scientists from among that populace, all while investments in basic research are stagnant or even declining in many countries. The Decadal Vision (Plant Science Research Summit, 2013) represents a response from that community, one that launches a meaningful and ongoing dialogue about how best to accomplish these goals. In that spirit, we welcome this thoughtful commentary by Cathie Martin (Martin, …

Arbuscular Mycorrhizal Fungi Differ In Their Ability To Regulate The Expression Of Phosphate Transporters In Maize (Zea Mays L.), Hui Tian, Rhae A. Drijber, Xiaolin Li, Daniel N. Miller, Brian J. Wienhold

Department of Agronomy and Horticulture: Faculty Publications

Previous studies have found that some phosphate (Pi) starvation inducible transporter genes are downregulated and arbuscular mycorrhizal (AM) inducible Pi transporter genes are upregulated in maize roots associated with the fungus Glomus intraradices. However, little is known about the functional diversity of different AM fungal species in influencing the expression of Pi transporters in maize roots. Here, we studied the expression of two Pi transporter genes ZEAma:Pht1;3 (Pi starvation inducible) and ZEAma:Pht1;6 (AM inducible) in maize root colonized by different AM fungal inoculants. Non-mycorrhizal maize, maize colonized by Glomus deserticola (CA113), Glomus intraradices (IA506), Glomus mosseae (CA201), Gigaspora gigantea …

The Amino Acid Permeases Aap3 And Aap6 Are Involved In Root-Knot Nematode Parasitism Of Arabidopsis, Heather H. Marella, Erik Nielsen, Daniel P. Schachtman, Christopher G. Taylor

Department of Agronomy and Horticulture: Faculty Publications

The root-knot nematode, Meloidogyne incognita, is an obligate parasite which depends entirely on the host plant for its nutrition. Root-knot nematodes induce the formation of a highly specialized feeding site consisting of several giant cells surrounded by a network of vascular tissues. Nutrients, including amino acids and sugars, are transferred apoplastically from the vascular tissues to the feeding site. Using Arabidopsis thaliana lacking the vascular-expressed amino acid permeases (AAP) AAP3 or AAP6, we demonstrate that disruption of amino acid transport can affect nematode parasitism. Nematode infestation levels are significantly reduced on the aap3 and aap6 mutants. AAP3 and AAP6 …

Genetic Dissection Of Yield And Its Component Traits Using High-Density Composite Map Of Wheat Chromosome 3a: Bridging Gaps Between Qtls And Underlying Genes, Sachin Rustgi, Mustafa N. Shafqat, Neeraj Kumar, P. Stephen Baenziger, M. Liakat Ali, Ismail M. Dweikat, B. Todd Campbell, Kulvinder Singh Gill

Department of Agronomy and Horticulture: Faculty Publications

Earlier we identified wheat (Triticum aestivum L.) chromosome 3A as a major determinant of grain yield and its component traits. In the present study, a high-density genetic linkage map of 81 chromosome 3A-specific markers was developed to increase the precision of previously identified yield component QTLs, and to map QTLs for biomass-related traits. Many of the previously identified QTLs for yield and its component traits were confirmed and were localized to narrower intervals. Four novel QTLs one each for shoot biomass (Xcfa2262-Xbcd366), total biomass (wPt2740-Xcfa2076), kernels/spike (KPS) (Xwmc664-Xbarc67), and Pseudocercosporella induced lodging ( …

Sorghum Transformation: Overview And Utility, Tejinder Kumar, Arlene Howe, Shirley Sato, Ismail M. Dweikat, Tom E. Clemente

Department of Agronomy and Horticulture: Faculty Publications

Over the past decade genomics resources available for sorghum have rapidly expanded (Paterson Int J Plant Genomics 2008:6, 2008), these resources, coupled with the recent completion of the genome sequence which is relatively small in size (730 Mb) (Paterson et al. Nature 457:551–556, 2009) makes sorghum a rather attractive species to study. Moreover, the USDA germplasm system maintains 42,614 accessions, of which more than 800 exotic landraces have been converted to day length-insensitive lines to facilitate their use in breeding programs. In addition, a set of EMS mutation stocks developed by the USDA Plant Stress and Germplasm Development Unit in …

Nutrient Partitioning And Grain Yield Of Tanam-Rnai Wheat Under Abiotic Stress, Mary J. Guttieri, Ricardo J. Stein, Brian M. Waters

Department of Agronomy and Horticulture: Faculty Publications

Aims — Decreased expression of TaNAM genes by RNAi results in delayed senescence and decreased grain protein, iron, and zinc concentrations. Here, we determined whether NAM expression level alters onset of senescence under stress conditions, whether delayed senescence in the TaNAM-RNAi line resulted in improved tolerance to post-anthesis abiotic stress, and determined the effects of post-anthesis abiotic stress on N and mineral remobilization and partitioning to grain.

Methods — Greenhouse-grown WT and TaNAM-RNAi wheat were characterized in two studies: three levels of N fertility or water limitation during grain fill. Studies were conducted under both optimal and heat stress …

Enzyme Activity In Wheat Breeding Lines Derived From Matings Of Low Polyphenol Oxidase Parents, Somrudee Nilthong, Robert A. Graybosch, P. Stephen Baenziger

Department of Agronomy and Horticulture: Faculty Publications

Polyphenol oxidase (PPO) in grain plays a major role in time-dependent discoloration of wheat (Triticum aestivum L.) products, especially fresh noodles. Breeding wheat cultivars with low or nil PPO activity can reduce undesirable product darkening. The low PPO line PI 117635 was crossed to two low PPO wheats, IDO580 and ‘IDO377s’, to determine whether matings between wheats with low levels of grain PPO would result in complementation, such that lines with still lower or nil PPO would be generated. Progeny in a population derived from PI 117635/ IDO580 displayed no variation in PPO activity. In the F_3:4 populations …

Unleashing The Potential Of The Root Hair Cell As A Single Plant Cell Type Model In Root Systems Biology, Zhenzhen Qiao, Marc Libault

Department of Agronomy and Horticulture: Faculty Publications

Plant root is an organ composed of multiple cell types with different functions.This multicellular complexity limits our understanding of root biology because -omics studies performed at the level of the entire root reflect the average responses of all cells composing the organ. To overcome this difficulty and allow a more comprehensive understanding of root cell biology, an approach is needed that would focus on one single cell type in the plant root. Because of its biological functions (i.e., uptake of water and various nutrients; primary site of infection by nitrogen-fixing bacteria in legumes), the root hair cell is an attractive …

Food Webs And Food Sovereignty: Research Agenda For Sustainability, Charles A. Francis, Michelle Miller, Molly Anderson, Nancy Creamer, Michelle Wander, Jacob Park, Thomas Green, Brent Mccown

Department of Agronomy and Horticulture: Faculty Publications

Future food production will be constrained by the scarcity of fossil fuel and fresh water as well as increasing intensity and unpredictability of weather events and climate changes. The assurance of food security and equity for many consumers is complicated by concentration of ownership of land and other production resources, as well as a global corporate food systems model that is driven by profit at the expense of people and the environment. To assess potential alternatives to the contemporary global food chain, well focused research is needed on local food production and food webs where small- and midscale family farms …

Food Availability Of Glucose And Fat, But Not Fructose, Increased In The Us Between 1970 And 2009: Analysis Of The Usda Food Availability Data System, Trevor J. Carden, Timothy P. Carr

Department of Nutrition and Health Sciences: Faculty Publications

Background: Obesity rates in the United States have risen consistently over the last four decades, increasing from about 13% of the population in 1970 to more than 34% in 2009. Dietary fructose has been blamed as a possible contributor to the obesity increase, although the consumption pattern of fructose and other key nutrients during this 40 year period remains a topic of debate. Therefore, we analyzed the USDA Loss-Adjusted Food Availability Database in combination with the USDA Nutrient Database for Standard Reference (Release 24) to determine whether fructose consumption in the US has increased sufficiently to be a casual …

Identification And Assessment Of Markers Of Biotin Status In Healthy Adults, Wei Kay Eng, David Giraud, Vicki L. Schlegel, Dong Wang, Bo Hyun Lee, Janos Zempleni

Department of Nutrition and Health Sciences: Faculty Publications

Human biotin requirements are unknown and the identification of reliable markers of biotin status is necessary to fill this knowledge gap. Here, we used an outpatient feeding protocol to create states of biotin deficiency, sufficiency and supplementation in sixteen healthy men and women. A total of twenty possible markers of biotin status were assessed, including the abundance of biotinylated carboxylases in lymphocytes, the expression of genes from biotin metabolism and the urinary excretion of biotin and organic acids. Only the abundance of biotinylated 3-methylcrotonyl-CoA carboxylase (holo-MCC) and propionyl-CoA carboxylase (holo-PCC) allowed for distinguishing biotin-deficient and biotin-sufficient individuals. The urinary excretion …

Polyphenols, Inflammation, And Cardiovascular Disease, Christy Tangney, Heather E. Rasmussen

Department of Nutrition and Health Sciences: Faculty Publications

Polyphenols are compounds found in foods such as tea, coffee, cocoa, olive oil, and red wine and have been studied to determine if their intake may modify cardiovascular disease (CVD) risk. Historically, biologic actions of polyphenols have been attributed to antioxidant activities, but recent evidence suggests that immunomodulatory and vasodilatory properties of polyphenols may also contribute to CVD risk reduction. These properties will be discussed, and recent epidemiological evidence and intervention trials will be reviewed. Further identification of polyphenols in foods and accurate assessment of exposures through measurement of biomarkers (i.e., polyphenol metabolites) could provide the needed impetus to examine …

A Framework For Managing Airport Grasslands And Birds Amidst Conflicting Priorities, Bradley F. Blackwell, Thomas W. Seamans, Paige M. Schmidt, Travis L. Devault, Jerrold L. Belant, Mark J. Whittingham, James A. Martin, Esteban Fernández-Juricic

United States Department of Agriculture Wildlife Services: Staff Publications

Management of modern airports is a task beset by conflicting priorities. Airports are vital to the global market economy, but impose costly environmental disturbances including habitat loss, noise, reduced air quality, erosion, introduction of invasive organisms, and polluted storm-water runoff (Blackwell et al. 2009). Airport environments also attract some wildlife hazardous to aviation safety, namely species involved in wildlife-aircraft collisions or ‘strikes’ (ICAO 2001, Blackwell et al. 2009, DeVault et al. 2011). Since 1912 at least 276 human lives have been lost due to bird strikes (Thorpe 2010), and from 1990 to 2010, more than 106 000 bird strikes involving …

Comparison Of Two Models For Estimating Mortality From Baitings With Compound Drc-1339 Concentrate Avicide, Jeffrey H. Homan, Randal S. Stahl, George M. Linz

United States Department of Agriculture Wildlife Services: Staff Publications

In the U.S., DRC-1339 baitings for blackbirds (Icteridae) are generally done under the pesticide label, Compound DRC-1339 Concentrate e Staging Areas. DRC-1339 is a slow-acting avicide and gives the birds enough time to leave the baiting sites. Carcass searches and other forms of onsite counts are ineffective. Instead, linear models (LM) are used. The LM are based on esophageal analyses of several blackbird species collected while feeding at staging area bait sites. Biases and large variances can occur with this type of sampling. As an alternative to the LM, we developed a semi-mechanistic model (SM) that combined mechanistic modeling of …

Comparison Of Two Models For Estimating Mortality From Baitings With Compound Drc-1339 Concentrate Avicide, H. Jeffrey Homan, Randal S. Stahl, George M. Linz

United States Department of Agriculture Wildlife Services: Staff Publications

In the U.S., DRC-1339 baitings for blackbirds (Icteridae) are generally done under the pesticide label, Compound DRC-1339 Concentrate ‒ Staging Areas. DRC-1339 is a slow-acting avicide and gives the birds enough time to leave the baiting sites. Carcass searches and other forms of onsite counts are ineffective. Instead, linear models (LM) are used. The LM are based on esophageal analyses of several blackbird species collected while feeding at staging area bait sites. Biases and large variances can occur with this type of sampling. As an alternative to the LM, we developed a semi-mechanistic model (SM) that combined mechanistic modeling of …

The Influence Of Snowmobile Trails On Coyote Movements During Winter In High-Elevation Landscapes, Eric M. Gese, Jennifer L. B. Dowd, Lise M. Aubry

United States Department of Agriculture Wildlife Services: Staff Publications

Competition between sympatric carnivores has long been of interest to ecologists. Increased understanding of these interactions can be useful for conservation planning. Increased snowmobile traffic on public lands and in habitats used by Canada lynx (Lynx canadensis) remains controversial due to the concern of coyote (Canis latrans) use of snowmobile trails and potential competition with lynx. Determining the variables influencing coyote use of snowmobile trails has been a priority for managers attempting to conserve lynx and their critical habitat. During 2 winters in northwest Wyoming, we backtracked coyotes for 265 km to determine how varying snow …

Anthropogenic And Physiologically Induced Stress Responses In Captive Coyotes, Christopher J. Schell, Julie K. Young, Elizabeth V. Lonsdorf, Rachel M. Santymire

United States Department of Agriculture Wildlife Services: Staff Publications

Repeated stressful events can negatively impact overall health by continuous stimulation of the hypothalamic– pituitary–adrenal axis, which leads to depletion of glucose stores and suppression of immune and reproductive function. The influence of stressors on survivability is particularly salient for coyote (Canis latrans) populations, because understanding how coyotes cope with stressors may provide relevant context on coyote adaptation to urbanized ecosystems. Our objectives were to physiologically validate fecal glucocorticoid metabolite (FGM) analysis in coyotes by performing an adrenocorticotropic hormone (ACTH) challenge in 12 captive individuals (6 treatment and 6 control) housed at the United States Department of Agriculture …

Twenty Years Of Immunocontraceptive Research: Lessons Learned, Lowell A. Miller, Kathleen A. Fagerstone, Douglas C. Eckery

United States Department of Agriculture Wildlife Services: Staff Publications

The National Wildlife Research Center (NWRC) began immunocontraception vaccine research by testing porcine zona pellucida (PZP) on white-tailed deer (Odocoileus virginianus). Early PZP research demonstrated that PZP induced infertility; however, increased length of the rut was observed in PZP-treated deer. An alternative vaccine using a keyhole limpet hemocyanin-gonadotropin-releasing hormone (KLH-GnRH) conjugate formulated with modified Freund’s adjuvant was developed at NWRC. Suppression of GnRH has reduced reproduction in both sexes but is most effective in females. This vaccine was effective in preventing contraception in female deer for several years after a prime and boost. Due to adverse side effects …

Dietary Niche Differentiation Among Three Species Of Invasive Rodents (Rattus Rattus, R. Exulans, Mus Musculus), Aaron B. Shiels, Caitlin A. Flores, Arthur Khamsing, Paul D. Krushelnycky, Stephen M. Mosher, Donald R. Drake

United States Department of Agriculture Wildlife Services: Staff Publications

The diets of sympatric rodents partially define their realized niches. Identifying items in stomachs of introduced rodents helps determine rodents’ trophic positions and species most at risk of consumption. In the Hawaiian Islands, which lacked rodents prior to human arrival, three rodents (Rattus rattus or black rat, R. exulans or Pacific rat, Mus musculus or house mouse) commonly coexist in native habitats where they consume a wide range of plants and animals. These three rodent species were trapped in montane forest for 2.5 years; their stomach contents were analyzed to determine short-term diets (n = 12–95 indiv. per species), …

The Effects Of Vitamin K1-Rich Plant Foods On The Efficacy Of The Anticoagulant Rodenticides Chlorophacinone And Diphacinone, Used Against Montane Voles (Microtus Montanus), Gary W. Witmer, Nathan P. Snow, Rachael S. Moulton

United States Department of Agriculture Wildlife Services: Staff Publications

Voles can cause significant losses to agriculture and wood fibre production. California growers typically rely on baits containing chlorophacinone and diphacinone to reduce vole population densities, but the efficacy of those rodenticides has been decreasing. One hypothesis suggests that voles are consuming high levels of an antidote (vitamin K1) to the anticoagulants, contained within green leafy plants. We tested that hypothesis by first feeding Montane Voles (Microtus montanus) diets that were high in vitamin K1, and then providing the animals with either: (1) chlorophacinone-containing bait, (2) diphacinone-containing bait, or (3) a control diet. We found that the chlorophacinone-containing …

Managing Turfgrass To Reduce Wildlife Hazards At Airports, Brian E. Washburn, Thomas W. Seamans

United States Department of Agriculture Wildlife Services: Staff Publications

Multiple factors-including safety regul at ions, economic considerations, location, and attrae· tiveness to wildlife recognized as hazardous to avia· tion-influence the choice of land cover at airports. The principal land cover at airports within North America has historically been turfgrass. usually cool· season perennial grass species native to Europe. However, recent research has determined that, from a wildlife perspective, not all turfgrasses are alike. Some grasses are more palatable to herbivorous hazardous wildlife (e.g., Canada geese [Branta canadensis]) than others, and thus are more likely to increase the potential for wildlife-aircraft collisions when planted near critical airport operating …

References From Landslide Ecology, Lawrence R. Walker, Aaron B. Shiels

United States Department of Agriculture Wildlife Services: Staff Publications

No abstract provided.

Chapter 3 Physical Causes And Consequences For Landslide Ecology, Lawrence R. Walker, Aaron B. Shiels

United States Department of Agriculture Wildlife Services: Staff Publications

1. The propensity for a landslide to occur is largely determined by potential slip planes, or weakness planes in the geological substrate, where the driving forces exceed resisting forces.

2. Landslide occurrence across the landscape is often unpredictable; substrates can be resistant to slippage for centuries and then suddenly experience instability that may result from human or non-human changes that disrupt the balance between driving and resisting forces at a slip plane.

3. Post-landslide erosion is common and can contribute as much as 33% of the total sediment loss from the site of landslide initiation. Such post-landslide erosion can continue …

Wildlife In Airport Environments: Chapter 10 Managing Turfgrass To Reduce Wildlife Hazards At Airports, Brian E. Washburn, Thomas W. Seamans

United States Department of Agriculture Wildlife Services: Staff Publications

Multiple factors-including safety regulations, economic considerations, location, and attractiveness to wildlife recognized as hazardous to aviation- influence the choice of land cover at airports. The principal land covet at airports within North America has historically been turfgrass, usually coolseason perennial grass species native to Europe. However, recent research has determined that, from a wildlife perspective, not all turf grasses are alike. Some grasses are more palatable to herbivorous hazardous wildlife (e.g., Canada geese [Branta canadensis]) than others, and thus are more likely to increase the potential for wildlife-aircraft collisions when planted near critical airport operating areas. How turfgrasses are managed …

Wildlife In Airport Environments: Chapter 3 Effectiveness Of Chemical Repellents In Managing Birds At Airports, Larry Clark, Michael L. Avery

United States Department of Agriculture Wildlife Services: Staff Publications

Repellents include methods and devices used to manipulate behavior of animals to reduce damage or nuisance. Critical to the design and success of repellents is understanding how sensory modalities mediate perception of signals, and how ecological context and sensory inputs influence animal learning. A repellent's success is tied to the axiom of using the proper tool for the proper job. When repellents "fail," it is almost always because wildlife managers have not appropriately matched signal, receiving systems, message, and context. Reconciling such considerations can be a complex process. In this chapter we review components and processes essential for the successful …

Wildlife In Airport Environments: Chapter 8 Identification And Management Of Wildlife Food Resources At Airports, Travis L. Devault, Brian E. Washburn

United States Department of Agriculture Wildlife Services: Staff Publications

Wildlife use airport habitats for a variety of reasons, including breeding, raising young, resting, taking refuge from predators, and locating sources of water. But the chief motivation for most individuals to encroach on airports is food. Depending on the specific habitat types present and habitat management strategies employed, airports can harbor large numbers of small mammals, insects, earthworms, and palatable vegetation that attract many species hazardous to aircraft. Often the best way to reduce populations of hazardous wildlife at airports is to determine which sources of food are being used, and then remove or modify those foods to make them …

Agronomy & Horticulture Newsletter, December 21, 2012, Kathy Schindler

Department of Agronomy and Horticulture: Monthly Newsletters

In the news..................1

Undergraduate students win awards..................1

ActivityInsight is replacing eARFA..................1

Free Blackboard training available for instructors..................1

Aaron Lorenz honored by DuPont Young Professors program..................2

Gaussoin selected for committee..................2

Winter Interim Teaching and Learning Workshop to be held..................2

News for and about Graduate students..................3

Travel Fund applications due Jan. 15..................3

New grandson arrives..................3

Food Access And Food Choice: Applications For Food Deserts, Gayaneh Kyureghian, Rodolfo M. Nayga Jr.

Cornhusker Economics

Poor food choices have been shown to contribute to the rise of major chronic diseases, including overweight and obesity (Centers of Disease Control and Prevention (CDC)). Consequently, the Dietary Guidelines for Americans, 2010, emphasizes the need to shift food intake patterns to a more plant-based diet that emphasizes nutritious food, such as fruits and vegetables. Despite these efforts only 42 percent, and less than 60 percent of Americans, meet the recommendations for fruit and vegetable consumption, respectively. In academic and policy circles as well as in the public eye, the local food environment has been associated with food choices and …

Eating Patterns And Physical Activity Characteristics Among Urban And Rural Students In Saudi Arabia, Omar I. Abuzaid

Department of Nutrition and Health Sciences: Dissertations, Theses, and Student Research

Human obesity has become a global phenomenon. The main goal of this study was to investigate the differences in food consumption and physical activity among high school age youth in two diverse geographical locations (urban and rural areas) and the relationship of some of the factors that may lead to overweight and obesity in Saudi Arabia. There were 300 (150 males and 150 females) high school senior grade level students, recruited from the urban city of Riyadh and 300 high school students recruited from the rural areas of Dawadami (150 males and 150 females). Approval for this study was given …

Seasonal Dimorphism In The Horny Bills Of Sparrows, Russell Greenberg, Matthew Etterson, Raymond M. Danner

United States Environmental Protection Agency: Publications

Bill size is often viewed as a species-specific adaptation for feeding, but it sometimes varies between sexes, suggesting that sexual selection or intersexual competition may also be important. Hypotheses to explain sexual dimorphism in avian bill size include divergence in feeding niche or thermoregulatory demands, intrasexual selection based on increased competition among males, or female preference. Birds also show seasonal changes in bill size due to shifts in the balance between growth rate and wear, which may be due to diet or endogenous rhythms in growth. Insight into the function of dimorphism can be gained using the novel approach of …