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

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.