1890 Faculty Research Sabbatical Program

The world is awash with petroleum-based microplastics with indefinite life, ill-defined but worrisome health hazards, and no immediate solutions to limit their production or distribution. The need for environmentally friendlier, potentially health-neutral, bio-based polymers is immediate and urgent. Agricultural feedstocks once the basis of the industrial production represent again a huge opportunity for future economic development for countries such as the United States whose large land mass and highly productive agricultural sector have an enviable record in technological innovations. Utilizing agricultural products such as soybeans and maize to make value-added, eco-friendly, and green products will make this planet a better place to live as they cause minimal harm to people and the environment. Highly desirable is the development of technologies that can exploit these raw materials to make consumer products that do not pollute the world and are non-hazardous to humans.

Bacterial wilt (BW) caused by the gram-negative Erwinia tracheiphila (Et) is a serious disease in cucurbit crops (cucumber, melon, watermelon, squash/pumpkin) with annual losses of more than $13 million to the growers in the eastern U.S. Yield loss from BW damage can exceed 80% of the total yield since infected plants typically collapse and die before harvest. Et is vectored by three species of cucumber beetles which carry Et in their mouth parts and gut and transmit it when the beetles feed and deposit frass on cucurbit plants. Insecticides, currently the predominant weapon against cucumber beetles are environmentally hazardous because they impair foraging behavior and endanger survival of honeybees and other pollinator species. Deployment of resistant varieties is an important strategy in BW management which is both economically and environmentally sound. However, resistant cucurbit varieties are not widely available in production, and little is known about the genetic basis and molecular mechanisms of host resistance to BW in cucurbit crops. The development of more effective and environmentally safe management strategies for BW also requires fundamental scientific knowledge on the pathogen, the vectors, the cucurbit hosts, and their interactions. In a continuation of a previously initiated collaboration, Dr. Korsi Dumenyo, from Tennessee State University will spend the summer months of the next two years on sabbatical leave in the laboratories of Drs. Yiqun Weng and Dennis Halterman of ARS, in Madison, Wisconsin working on this project. The objectives of this project are three-fold: 1) Identification of genes and QTL for BW resistance in cucumber; 2. Development of molecular tools for the genetic manipulation and identification of key pathogenesis players in Et during interaction with cucumber host; and 3. Leveraging and strengthening existing research collaboration in molecular plant-pathogen interactions between ARS and Tennessee State University laboratories. Expected outcomes from the project include identification of genes and QTL for BW resistance in cucumber, publication in peer-reviewed journals, presentations in scientific conferences, incorporation of findings in classroom teaching, and strengthen the collaboration between ARS and Tennessee State University. This project will provide novel insights into the genetic basis and molecular mechanisms of BW resistance in cucumber, facilitate/accelerate marker-assisted breeding of BW resistance in cucumber breeding, and enable a better understanding of the molecular mechanisms of pathogenesis by Et in the tri-trophic BW pathosystem. In the long term, the activities and outcomes of the project will serve our long-term goal to increase productivity of cucurbit production and increased research and education capacity of Tennessee State University.

Seafood demand in the U.S. greatly exceeds the supply generated by capture fisheries and domestic aquaculture. Aquaculture has the potential to meet critical protein needs for people into the future. Growth of the US aquaculture industry in an environmentally responsible way requires the identification of cost-effective, nutritionally equivalent replacements for marine fish meal in diets. The University of Arkansas at Pine Bluff (UAPB) and the USDA-ARS Harry K. Dupree Stuttgart National Aquaculture Research Center (SNARC) both conduct seminal research to assist the state’s vibrant aquaculture industry. The overall objective of this project is to identify plant and insect sources of protein that can replace marine fish meal effectively in diets of an established species (hybrid striped bass), and an emerging species (white bass) with potential for commercial culture. Elimination of marine fish meal from diets for both species would facilitate sustainable growth of the aquaculture industry, while optimizing profit potential for domestic producers. Dr. Carl Webster (SNARC) and Dr. Rebecca Lochmann (UAPB) will implement the following specific objectives: 1) Evaluate the growth performance, body composition, gut histology and gene expression of sunshine bass and white bass fed soy-based diets enhanced with palatants; and 2) Evaluate the growth performance, body composition, gut histology and gene expression of sunshine bass and white bass fed diets with insect meals and oils. The proposed research will provide ground-breaking data to facilitate formulation of cost-effective, nutritious, and sustainable diets for the aquaculture industry. In addition, the project formalizes a significant research partnership between UAPB and SNARC that will provide comprehensive benefits to the Arkansas aquaculture industry and other interested stakeholders.

The project will develop computational technologies for data pre-processing, data segmentation, feature extraction, and classification using aerial images and other photos of peach fruit and trees, to facilitate collecting peach phenotype data. Specifically, the project will design image processing algorithms to process peach fruit and tree images to collect the phenotype data on fruit characteristics (e.g., fruit color, size, density, and distribution) and tree health status (healthy vs diseased) based on leaves, canopies and other distinguishable subjects. The computational technologies can hasten peach breeding and are also potentially useful for peach orchard management. The project will primarily consist of two phases with 3 months for each phase. In phase I, the project will identify mature peach fruit and healthy peach trees of different angles based on designed image processing algorithms. In phase II, the project will detect peach tree fruit ripening stages (unripe vs. ripe - using blush color and fruit size as the primary indicator) and tree health statues (healthy vs. diseased - using phony peach disease as an example), based on modified algorithms in phase I. The project will initialize the interdisciplinary research collaboration between expertise in peach breeding in SEFTNRL and computer science at FVSU, and help local peach industries' orchard management and fruit harvest and quality control based on the research results in the long run.

Climate change and management impacts on sagebrush may change the distribution of subspecies, thus changing the communities of other species with which sagebrush interacts. Insect galls represent a unique potential for an easily observed indicator of insect diversity, plant genotype diversity and plant health. While many insects move from plant to plant or may be hard to observe, galling insects induce the development of novel plant organs that can remain on the plant for several seasons, thereby leaving a record of growth, insect presence and other factors. With the help of a VSU graduate student, we will examine gall and plant diversity under different management and elevation conditions using field and molecular techniques to characterize these complex relationships. The efforts of this project will result in a baseline survey of insect gall diversity for the field station that can be used for future studies by the collaborators as well as to educate and inform local stakeholders, develop teaching modules, and train URM undergraduates in ecology.

Although staphylococci can be found as natural inhabitants of the skin of humans and animals, staphylococcal species may also cause infections in those same tissues and other diseases as well. The best-known staphylococcal species, Staphylococcus aureus, is the second most frequently reported pathogen in healthcare-associated infections responsible for diverse types of infections ranging from superficial skin and soft tissue infections to fasciitis, otitis media, necrotizing pneumonia and urinary infections. In addition, S. aureus is one of the major causes of food poisoning due to their ability to produce heat stable enterotoxins that may remain protected in the food environment and cause foodborne illness.

Objective 1-Evaluate the antimicrobial-resistant staphylococcal population in the bacterial microbiome from poultry.
Overview: In this objective, all species of staphylococci will be isolated from conventional and “No Antibiotics Ever (NAE)” retail poultry products. Isolates will be tested against a panel of antimicrobials and the bacterial genomes analyzed using whole-genome sequencing. As little is known about non-aureus staphylococcal species, this objective will primarily focus on those species. The goals of this objective are to determine: 1) prevalence of poultry staphylococcal species and 2) non-aureus reservoirs of antimicrobial resistance genes that could ultimately be transferred to Staphylococcus aureus.

Objective 2-Identify and characterize potential poultry specific signatures from methicillin-resistant Staphylococcus aureus (MRSA) to differentiate from livestock-associated MRSA (LA-MRSA).
Overview: The goal of this objective is to identify genetic markers that are unique to MRSA from poultry useful for development of rapid screening tests for on-farm or in-plant testing of poultry products. Experiments in this objective would focus specifically on MRSA from Objective 1. Genome-wide association studies will be performed to compare poultry MRSA to those classified as LA-MRSA to determine differences between the two groups.