title: Point mutation is responsible for Arabidopsis tz-201 mutant phenotype affecting thiamin biosynthesis.
abstract: A point mutation in the thi1 gene, involved in the synthesis of thiamin, has been identified in a tz-201 mutant line of Arabidopsis thaliana. The mutation occurs in a conserved protein domain and prevents the mutant plants from synthesizing thiamin. Complementation assays in yeast thi4 mutant confirm that this mutation hinders thiamin synthesis and, thus, is responsible for the tz phenotype. Northern blot analyses indicate that, in contrast to the yeast homologue, thi1 expression is not influenced by the presence of thiamin; however, reduced transcription of the gene is observed in roots and dark grown plants.
authors.affiliation: Depto de Botânica, Instituto de Biociências, Universidade de São Paulo, Rua do Matão, 277-05508-900 São Paulo, SP, Brazil.
authors.forename: Flávia Stal
authors.initials: FS
authors.lastname: Papini-Terzi
authors.forename: Rodrigo Silva
authors.initials: RS
authors.lastname: Galhardo
authors.forename: Leonardo Paiva
authors.initials: LP
authors.lastname: Farias
authors.forename: Carlos Frederico Martins
authors.initials: CF
authors.lastname: Menck
authors.forename: Marie-Anne
authors.initials: MA
authors.lastname: Van Sluys
mesh_terms: D000595:Amino Acid Sequence; D017360:Arabidopsis / Q000235:genetics*; D029681:Arabidopsis Proteins / Q000235:genetics* / Q000502:physiology; D004268:DNA-Binding Proteins / Q000235:genetics* / Q000502:physiology; D020869:Gene Expression Profiling; D008969:Molecular Sequence Data; D010641:Phenotype; D017354:Point Mutation; D017386:Sequence Homology, Amino Acid; D013831:Thiamine / Q000096:biosynthesis*; D014157:Transcription Factors / Q000235:genetics* / Q000502:physiology
chemical_list: D029681:Arabidopsis Proteins; D004268:DNA-Binding Proteins; C437085:THI1 protein, Arabidopsis; D014157:Transcription Factors; D013831:Thiamine