Biological Sciences, School of


Date of this Version

Winter 12-7-2010


A THESIS Presented to the Faculty of The graduate College at the University of Nebraska In partial Fulfillment of Requirements For the Degree of Master of Science, Major: Biological Sciences, Under the Supervision of Professor Zoya Avramova. Lincoln, NE: December, 2010
Copyright 2010 Yang Zhao


Phosphatidylinositol 5 phosphate is appearing to play an important role in signal transduction as lipid second messenger. The synthesis of this lipid signal is mainly conducted by a group of phosphatase called myotubularins (MTM) which can dephosphorylate on the 3’s position of Phosphatidylinositol (3, 5) bi-phosphate. Mutations in active myotubularins lead to severe diseases in human. However, this essential family has been scarcely studied in plants. Recently, two myotubularins (AtMTM1 and AtMTM2) have been identified as the homologs of human MTM Related protein 2 (MTMR2) in Arabidopsis. While some evidence has been provided to suggest the function of AtMTM1, the knowledge of AtMTM2 is really little. In this study, we reported here that AtMTM1 increases significantly in hydathods after dehydration stress but no obvious change on AtMTM2 expression was observed, while both extensively present in roots, leaves, flowers and siliques. AtMTM2 exists not only in cytoplasm and membrane like AtMTM1, but also in the nucleus. AtMTM1 knockout mutant showed a more tolerant phenotype to drought compared with wild type, but knockout of AtMTM2 didn’t cause visible deviation. Obtained results provide a ground for comprehensive further studies of AtMTM2 function and comparisons with AtMTM1.
Advisor: Zoya Avramova