Observation of Protein Activity in Sbe2.1 and Sbe2.2 T-DNA Mutants and Identification of a Sbe2.1/Sbe2.2 Double Mutant in Arabidopsis thaliana

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Protein activity, DNA, mutants, arabidopsis thaliana, biology


Biology | Cell and Developmental Biology | Genetics and Genomics | Life Sciences


An enhanced understanding of starch biosynthesis is important so more applications of starch can be developed. Several enzymes play important roles in the biosynthesis of starch, including starch synthase, starch branching enzymes, AGPase, debranching enzymes and d-enzymes. Arabidopsis thaliana is an excellent model organism for analyzing enzymes involved in starch synthesis. Two starch branching enzymes, Sbe2.1 and Sbe2.2 have been identified in Arabidopsis thaliana leaf tissue. Specific functions and expression patterns of enzymes can be determined by the analysis of mutants. T-DNA insertional mutagenisis is a successful and advantageous method that is commonly used in Arabidopsis. A T-DNA Sbe2.1 mutant and Sbe2.2 mutant have been identified. In order to verify that the genes were successfully obstructed by the T-DNA inserts, the starch branching activity must be tested in the Arabidopsis Sbe2.1 and Sbe2.2 mutants. Sbe assays as well as zymograms are two ways to SBE activity can be detected. The results of the first part of this study were unable to verify if there was reduced Sbe activity in the newly discovered T-DNA Sbe2.1 and Sbe2.2 mutants. In addition, the attempt to identify which genes encode the various Sbes was unproductive. Further development of the Sbe assay and Sbe zymogram is required to confirm if the Sbe genes present in the mutants are disrupted leading to a loss of function. The second part of this study involved crossing and screening plants for certain genotypes which resulted in the creation of a Sbe2.1/Sbe2.2. homozygous double mutant. Further tests can be performed on this double mutant to discover more about the roles of Sbes as well as aid in the development of additional applications of starch.

Department 1 Awarding Honors Status


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