This Is AuburnElectronic Theses and Dissertations

Functional Identification and Characterization of an Arabidopsis thaliana Gene Involved in Vitamin B6 Biosynthesis

Date

2005-12-15

Author

Porter, Charmaine

Type of Degree

Thesis

Department

Biological Sciences

Abstract

Vitamin B6 (pyridoxine) is a biological coenzyme seemingly involved in environmental stress tolerance and an important vitamin in human nutrition produced in plants as well as fungi and bacteria. A series of studies from these different organisms revealed that SNZ1/SNO1 homologues are the genes involved in the production of pyridoxine. We decided to functionally define SNO1 and SNZ1 orthologs and/or paralogs in the Arabidopsis thaliana genome by using transgenic yeast expressing putative SNZ1 or SNO1 homologs to suppress the growth defects of yeast ?snz1 and ?sno1. Using a blast search we were able to find Arabidopsis homologs of yeast SNZ1/SNO1. Moreover, we have obtained knockout deletion mutants of SNZ1 and SNO1 from S. cerevisiae and were able to confirm that the SNZ1 and SNO1 deletions did not grow as efficiently as wild type in media lacking pyridoxine. In addition, we were able to clone the putative A. thaliana SNZ1 into a high expression yeast shuttle vector (p426 GPD). Our results indicate that the AtSNZ1 does complement phenotypic expression of the SNZ1 knockout in yeast.