CRIS Project

Research: Weeds are the biggest problem that farmers face, yet we know virtually nothing about weed genomics and the genetic basis of weediness. In the coming decade, we will begin to study weed genomics, weed physiology, and herbicide tolerance. Of special interest is glyphosate tolerance evolution of weeds due to implementation of biotechnology and over reliance of single herbicides. We are studying the molecular mechanisms of resistance. Biosafety of Genetically Modified Plants. We have been funded by the USDA Biotechnology Risk Assessment since 1994. We are using the crop canola (Brassica napus) as a model to assess transgene flow, persistence and consequence to free-living wild relatives. In particular, we are interested in the effect the transfer of fitness-enhancing transgenes has on the consequences for agricultural and other ecosystems. A book on the ecological effects of genetic modification written by Neal Stewart is under contract by Oxford University Press. Among the tools used in the biosafety research is the green fluorescent protein-GFP. GFP. The Stewart lab has heavily used GFP and other fluorescent proteins expressed in plants and algae in gene flow experiments (ER and pollen targeted), and in use of plant bioreporters (termed phytosensors). Several companies and federal agencies have funded GFP research. Phytosensor research. Plants are being designed that can sense explosives, plant diseases, and chemical warfare agents. Genetic modification and mutagenesis procedures are being exploited to modify how plants perceive biological and chemical signals in the environment. Then, GFP or other output signals are produced that can be detected using simple to complex instrumentation. This research has been funded by defense and agricultural interests. Crop improvement. Soybean and other crops are being improved using plant transformation and mutagenesis. We are developing plants that can be used to help farmers with aluminum and drought problems, as well as damaging insects. We are also interested in producing novel ornamental and floral crops. This research has been funded by foundations and companies. Weed Genomics. Our latest interest is in the genomics underlying competitive trants, abiotic resistances and herbicide tolerance. Since there are hundreds of thousands of acres in Tennessee infested with glyphosate-tolerant horseweed (Conyza canadensis), we would like to understand the molecular mechanisms conferring tolerance. The tools we use in our research span molecular biology, genomics, physiology, and ecology. Students and postdocs will clone and sequence genes, express genes in transgenic plants and algae, and use microarrays and fluorescence technologies. Graduate students are supported on research assistantships and qualified candidates are being accepted for masters and doctoral degrees. Contact Neal Stewart if interested. The lab is also interested in hosting self-funded postdoctoral fellows and sabbatical leave fellows. Other postdocs are recruited for specific projects.