Final Report
This report summarizes our research activities. In the award period, we have made significant progress on the first aim, with new discoveries reported in one published paper (1) and in one submitted manuscript (2) currently under review. The published manuscript reports on our discovery of plant ribokinase and the metabolic pathway in which it functions; the submitted manuscript is identification and characterization of the plant fructokinase family of enzymes from expression studies, sequence comparisons, subcellular localizations and enzymatic activities of recombinant proteins. Our study of loss-of-function mutants in the fructokinase family members (2) revealed that there were no phenotypic differences observed for the five genes analyzed, so we have adopted the Crispr/Cas9 system to isolate mutants in the two genes for which there are no currently available insertion mutants, and we are generating higher order mutants (double, triples, etc) to discern the relative roles and significance for each fructokinase. These mutants will be an important resource to understand regulation of carbohydrate movement and catabolism in plants. As studies from others indicate, alteration of fructokinases results in changes in cell walls and vasculatures, which have importance relative to biofuel yield and quality. In the second aim, we have characterized the protein-protein interactions for the pkfB proteins FLN1 and FLN2 that are localized to chloroplast transcriptional complexes and have proposed a new model for how chloroplast transcription is regulated. This work has been submitted for publication, been revised and will be re-submitted in December 2016