He is a plant molecular physiologist experienced in biochemistry, specifically the application of mass spectrometry to research problems in genomics, bioenergy crop production, environmental stress physiology, and plant-microbe signaling. Current research includes metabolomics for phenotypic characterization of genetically-modified Populus, Arabidopsis, Eucalyptus, Castanea sp. (American and Chinese chestnut), switchgrass, and numerous bioenergy-relevant microbial species, and coupling metabolomics with genome-wide association studies to identify gene function. Research targets include the application of genomic tools for the accelerated domestication of Populus to reduce biomass recalcitrance to microbial deconstruction, increase drought tolerance and biomass productivity on marginal sites to increase crop sustainability, and to manipulate bioproduct formation. Most recent activities include characterizing the molecular basis of plant-microbe (bacterial and fungal) symbiotic relationships in contrast with pathogenic relationships. He has authored and co-authored 195 publications and currently serves as Research Council Member for the Center for Bioenergy Innovation, a U.S. Department of Energy (DOE) funded Bioenergy Research Center, is the Science Co-lead for the Plant-Microbe Interactions Science Focus Area of DOE, the ORNL lead PI for the Clostridial cBioFab Biodesign project with Northwestern University (Michael Jewett, PI) and LanzaTech, and the ORNL lead PI for the DOE-ARPA-E funded Carbon-Negative Chemical Production Platform project with LanzaTech (Steven Brown, lead PI) and the University of Michigan.