Role of Starch Branching Enzyme 3 (Sbe3) in Arabidopsis and its response to sugar signaling
Mentor:Susan Blauth, Professor, Biology, University of Redlands
Starch branching enzymes (SBE’s) allow for polymers of glucose to branch in a tree-like formation which allows for more glucose rings to be added onto the ends of the growing starch branches. We are exploring the role of starch branching enzyme 3 (Sbe3) in the model organism Arabidopsis and its response to sugar signaling by comparing the differences in Sbe2.1 and Sbe 2.2 mutants to the Sbe3 mutant under varying amounts of sugar concentrations and different sugars mediums. Wang et al. (2010) observed longer root length in response to sugars more extreme in the Sbe3 mutant than wild-type. However, we did not see a similar response between the Sbe3 mutant and the wild-type, due to a heightened response in the wild type controls. The response was even less pronounced in the Sbe2.1/2.2 mutants observed under the same conditions. This indicated that the Sbe3 may not be a starch branching enzyme, but may have a role in sugar signaling that is different from that of other Sbes.