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A Synthetic Approach to Redesigning Plants to Survive in Inhospitable Environments: Overexpression of Pyrococcus Furiosus Superoxide Reductase in Arabidopsis.  Y. Im¹, C. Lowder¹, M. Ji², A. M. Lee², A. M. Grunden² and W. F. Boss^{1     1}Department of Plant Biology and ²Department of Microbiology, North Carolina State University, Raleigh NC

   Reactive oxygen species (ROS) are early signals of environmental stress; however, if ROS build up within a cell, they will result in cell death. Plants, like other aerobic organisms, have ROS scavenging enzymes such as superoxide dismutase (SOD) that reduce superoxide and prevent the production and buildup of toxic free radicals; however, SOD produces oxygen which can serve as an additional source of ROS. Pyrococcus furiosus superoxide reductase (SOR) is a thermostable archaeal enzyme that reduces superoxide without producing oxygen. Our hypothesis was that expressing the P. furiosus SOR oxygen detoxification enzyme in plants would provide a more effective ROS reducing system. SOR should not only reduce the superoxide but also keep the oxygen levels low thus reducing the potential to generate more ROS and enhancing survival under stress conditions. We overexpressed P. furiosus SOR in Arabidopsis and produced a functional protein. The transgenic plants showed an enhanced tolerance to many different stimuli including heat, drought stress and pathogen attack. The SOR plants also provide us with a new system for studying the impact of ROS on plant growth and development.