The Stewart Lab has various research programs in plant biology, genomics and biotechnology to address mainly agricultural and environmental problems. Researchers pursue their own interests, meet goals of grants, and produce new knowledge in one of six specialty areas that overlap one another:
1. Plant-based bioenergy to fuel the future. The major project is sponsored by the Bioenergy Science Center (bioenergycenter.org) in which we are modifying switchgrass for improved cell wall characteristics. We are also interested in improving cellulosic feedstock growth and production with the necessity of deploying biocontainment technologies to assure biosafety and regulatory compliance. Finally, we are investigating plant-based terpenes and oils for improved biodiesel. Plants: switchgrass, novel grass feedstock candidates, and diesel trees.
2. Phytosensor research and development to produce smart plants to sense and report dangers. Phytosensors that change their morphology or biochemistry in a predicable way can be strategically deployed for homeland security, agricultural protection or to help clear landmines. The main targets of our phytosensors are plant pathogens, arsenic, and explosives. We employ genomics, synthetic plant promoters, reporter genes, and detection technologies towards the creation of functional phytosensors. Associated with this research is also phytoremediation—the potential of sensing and clean-up plants together. Plants: soybean, canola, Chinese brake fern, and model plants.
3. Gene flow and the prevention of gene flow from transgenic plants. Since 1994, the lab has studied plant hybridization, transgene introgression, and the ecological consequences of gene flow to wild and weedy relatives. In addition to understanding the effects of gene flow, we are interested in deploying biotechnology tools for biocontainment including site-specific recombination systems and male sterility. Plants: canola and wild relatives, papaya, tobacco and hybrids, and switchgrass.
4. Weed genomics. Weeds are amazing plants that have rapidly evolved to take advantage of agricultural systems. In the absence of aggressive weed control systems, these plants perform better in agriculture than crops, yet we know little about their adaptive genomics. We are especially interested in the spread and mechanisms of non-target herbicide resistance. Plants: horseweed and others.
5. Extremophytes. Understand the genomics of plants with extreme traits and capabilities could benefit research in all of our areas. We are participating in the Thousand Plant Transcriptome (1kp) consortium to curate dozens of extremophytes and weeds for transcriptome sequencing.
6. Other investigator-centered projects, related to nanoscience and detection. One example is related to food safety and another is investigating superglue produced by ivy plants.
As funding allows, we recruit qualified people to perform research—mainly graduate students and postdoctoral fellows. In addition, we have hosted several visiting scientists and students who have obtained their own support.
Stewart lab people in front of the Plant Biotech building on the University of Tennessee agriculture campus, June 2012.