Open AccessExpression Patterns of Duplicate Tryptophan Synthase [beta] Genes in Arabidopsis thaliana
Author(s) -
Kim D. Pruitt
Publication year - 1993
Publication title -
plant physiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.554
H-Index - 312
eISSN - 1532-2548
pISSN - 0032-0889
DOI - 10.1104/pp.102.3.1019
Subject(s) - biology , meristem , tryptophan synthase , arabidopsis thaliana , gene , reporter gene , microbiology and biotechnology , gene expression , beta glucuronidase , arabidopsis , gus reporter system , transgene , northern blot , genetics , escherichia coli , mutant
Expression of the two Arabidopsis thaliana genes encoding tryptophan synthase beta (TSB1 and TSB2) was investigated by gene-specific RNA blot hybridization and reporter gene analysis. TSB1 mRNA abundance varies in an organ-specific manner, whereas TSB2 mRNA does not. Quantitative analysis of transgenic plants expressing TSB1 and TSB2 translational fusions to the beta-glucuronidase (GUS) gene (gusA) indicates that TSB1-GUS activity is 15-fold higher than TSB2-GUS. Histochemical analysis of these transgenic A. thaliana plants indicates that GUS expression occurs in a developmentally regulated manner. GUS activity driven from the TSB1 promoter is predominantly associated with the stem, root tips, foliar vasculature, mesophyll cells, base of developing seed pods, and tips of anther filaments in plants 15 d and older. Sections through the vegetative stem reveal GUS staining in all cell types including the shoot apical meristem. Although TSB2-GUS expression is consistently detected in root tips and at the base of developing seed pods, it is observed later in plant development than is TSB1-GUS expression.