| Citation | Professor Somerville is distinguished for his original genetic and biochemical analysis of the metabolic pathways of photorespiration, which limits the photosynthetic efficacy of most plants. By selecting mutants of Arabidopsis which grow under atmospheric conditions which suppress photorespiration Somerville identified defects in 7 genes affecting this process. These involved enzymes in chloroplasts, peroxisomes and mitochondria, and the membrane translocators that control metabolite fluxes between these organelles. His research provided elegant and incontrovertible proof of a long controversial metabolic pathway and opens the way for genetic control of photorespiration. By achieving the first expression of ribulose bisphosphate carboxylase in E. coli Somerville provided the vehicle for synthesis and proof of intermediate reaction products, and the material for crystallographic analysis of the structure of this fundamental enzyme of photosynthesis and photorespiartion. Subsequently Somerville has turned his attention to the characterization of fatty acyl desaturases which determine, through lipid desaturation, the structural and functional aspects of photosynthetic membranes. He has isolated and cloned an altered acetolactate synthase gene which confers agronomically useful herbicide resistance in transgenic tobacco. This gene also serves as a natural selection criterion for use in plant molecular biology. |