Functional characterization of the thi1 promoter region from Arabidopsis thaliana.
The Arabidopsis thaliana THI1 protein is involved in thiamine biosynthesis and is targeted to both chloroplasts and mitochondria by N-terminal control regions. To investigate thi1 expression, a series of thi1 promoter deletions were fused to the beta-glucuronidase (GUS) reporter gene. Transgenic plants were generated and expression patterns obtained under different environmental conditions. The results show that expression derived from the thi1 promoter is detected early on during development and continues throughout the plant's life cycle. High levels of GUS expression are observed in both shoots and roots during vegetative growth although, in roots, expression is restricted to the vascular system. Deletion analysis of the thi1 promoter region identified a region that is responsive to light. The smallest fragment (designated Pthi322) encompasses 306 bp and possesses all the essential signals for tissue specificity, as well as responsiveness to stress conditions such as sugar deprivation, high salinity, and hypoxia.
Ribeiro
Denise Teixeira
DT
Depto. de Botânica, Instituto de Biociências, Universidade de São Paulo, Rua do Matão, 277, 05508-900 São Paulo, SP, Brazil.
Farias
Leonardo Paiva
LP
de Almeida
Juliana Dantas
JD
Kashiwabara
Priscila Mayumi
PM
Ribeiro
Alberto F C
AF
Silva-Filho
Marcio C
MC
Menck
Carlos Frederico Martins
CF
Van Sluys
Marie-Anne
MA
D017360:Arabidopsis / Q000235:genetics / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000378:metabolism*; D018506:Gene Expression Regulation, Plant; D018525:Germination; D008027:Light; D035261:Plant Components, Aerial / Q000378:metabolism; D018517:Plant Roots / Q000378:metabolism; D030821:Plants, Genetically Modified; D011401:Promoter Regions, Genetic; D012639:Seeds / Q000254:growth & development; D013831:Thiamine / Q000096:biosynthesis
D029681:Arabidopsis Proteins; C437085:THI1 protein, Arabidopsis; D013831:Thiamine