Honors Theses and Capstones

Date of Award

Spring 2024

Project Type

Senior Honors Thesis

College or School



Department of Molecular, Cellular, and Biomedical Sciences

Program or Major


Degree Name

Bachelor of Science

First Advisor

Estelle Hrabak


Protein Phosphatase 2A (PP2A) is a crucial enzyme in all eukaryotic organisms and is responsible for the regulation of many cellular processes. PP2A has a heterotrimeric structure consisting of one A, one B, and one C subunit, each with unique functions. Three A subunit isoforms are found in Arabidopsis thaliana encoded by unique genes called A1, A2, and A3. The A1 subunit has fundamental roles in seedling root growth and the absence of A1 produces distinct phenotypes when abiotic stresses are present in the environment. For example, a1-6 mutant seedlings display a severe root curling phenotype when grown in the presence of elevated but non-toxic concentrations of NaCl. Here, we show that the wildtype root phenotype can be restored in a1 mutant seedlings transformed with transgenes made with different combinations of A subunit promoters and coding region sequences. One explanation for this result could be that restoration of the wildtype phenotype can be achieved when sufficient levels of A subunit proteins are present, regardless of the specific A subunit.

Available for download on Saturday, June 02, 2029