Barney J. Venables - US grants

With National Science Foundation support, Dr. Steve Wolverton and an interdisciplinary team of colleagues will conduct a year of analytical chemistry research into removing trace-level food residues from archaeological pottery. The team brings together specialists in archaeology, protein chemistry, plant-lipid chemistry, and environmental biology to tackle what has been a sizeable hurdle in removing protein residues from archaeological cooking vessel fragments. Unlike other classes of food resides (e.g., fats), proteins bind very tightly to clay during cooking. This tight binding structure is, however, a blessing in disguise because it likely protects protein fragments from deterioration over time in archaeological sites. The challenge has been breaking those tight bonds between minerals in pottery clays and residues. Protein residues potentially provide a distinct scientific advantage to archaeologists over study of other food residues; proteins can be identified to species and tissue when they are preserved and removed from pottery (other residues offer only coarse resolution). Importantly, addressing this methodological challenge will provide a new basis for asking wide ranging questions in archaeology both in terms of studying prehistoric subsistence (what people ate) and pottery function (what people used their pottery for).

There are several important implications of this research. An ability to extract protein residues from pottery potentially enables researchers to study past subsistence and pottery function using a broader archaeological record. In areas where faunal (animal bones) and botanical (seeds, nuts, pollen) remains are poorly preserved?a common problem in archaeology?pottery residues might provide a unique source of information on past diet and artifact function. The technique can be applied to questions of agricultural origins, which is often associated with development of pottery in many parts of the world.

This research will be incorporated into a variety of educational settings, which includes exposure of under-represented cultural groups to this research. At the graduate level, archaeology and biochemistry students are integral components of this research.. The research will be disseminated to the general public through several avenues: 1) UNT?s Elm Fork Education Center, a science education program located on campus that reaches over 20,000 K-8 students each year; 2) Crow Canyon Archaeological Center, a nonprofit organization in Cortez, Colorado with archaeological education programs for the public, in particular students and educators; and 3) invited public lectures at schools, educational events, and local archaeological societies by members of the research team.

With National Science Foundation support, Dr Steve Wolverton and a team of archaeologists, analytical chemists, and proteomic biologists will do burial experiments with modern cooking pottery and research on archaeological pottery to evaluate the role of variability in climate, soil, and ceramic paste on the preservation of food protein residues. This project builds on previous research funded by NSF in which the same team addressed which types of solvents and physical conditions work best for extraction of protein residues from cooking pottery. Protein residues offer distinctive advantages over other types of food residues in that they bind to clay in pottery walls, which enhances preservation, and that proteins can often be identified to species or perhaps even to tissue. An important hurdle is that factors that mediate long-term preservation of protein residues have not been well studied, the focus of this project in both experimental and archaeological settings.

This research is important because it will provide a new set of tools which will allow archaeologists to examine previously inaccessible aspects of past culture. It will help to reconstruct past subsistence patterns and provide insight into how populations adapted to the environments in which they lived.

Residue analysis in general has lacked for detailed studies of method development. In terms of intellectual merit, the high potential of protein residues to provide precise data on what people cooked in pots in the past makes experimental replication of methods an essential process. Production of reliable analytical approaches and knowledge of conditions in which proteins are more and less likely to preserve will greatly amplify or current knowledge of protein residues from ancient foods.

This project involves students and professionals from Argentina and the United States, from a museum (Argentina), a non-profit public-education/archaeological research firm (US), and universities (US). The nature of the work is highly interdisciplinary, incorporating professionals with specialties in archaeology, ceramic petrography, material science, chemistry, and biology. The project will fund a graduate student for two academic years to work with this interdisciplinary team. Results will be published in scholarly journals and will be presented at academic conferences and in classroom settings.

The ability to induce defense systemically after a local infection allows plants to control disease spread to additional organs and ward off new infections. Dehydroabietinal, an abietane diterpenoid that is produced by a variety of plants, is a potent activator of systemic disease resistance, which is an inducible defense mechanism activated in the foliage in response to a local infection. The goal of this project is to characterize the involvement of dehydroabietinal as a long-distance signaling molecule in plant defense. A combination of genetic, biochemical, and molecular approaches will be utilized to accomplish this goal. The proposed activity will enhance our understanding of long-distance communication in plant defense and provide important insights into the function of abietane diterpenoids in plants.

Broader Impacts: This project will support the research and training of three graduate and two undergraduate students, and a postdoctoral fellow. They will receive training in plant biochemistry, molecular biology, genetics, organic chemistry, and mass spectrometry. In addition, through the instructional activities of the PI and Co-PIs, this project will bring current knowledge of plant signaling, secondary metabolism, and stress response, in addition to organic synthesis and mass-spectrometry techniques, into the classroom. The project will also provide opportunities to train high school students and future science teachers, and broaden the participation of underrepresented groups in research through several programs that are in place at the University of North Texas. This project will potentially benefit society at large by identifying steps in plant metabolism/signaling that mediate defense against pathogens. In the future these steps could be targeted for augmenting disease resistance in plants and thus enhance the quality and productivity of plants, and by way of limiting the need for toxic chemicals to protect plants, also benefit the environment and public health.