Maize DRE-binding proteins DBF1 and DBF2 are involved in rab17 regulation through the drought-responsive element in an ABA-dependent pathway.
Plant J
; 30(6): 679-89, 2002 Jun.
Article
en En
| MEDLINE
| ID: mdl-12061899
ABSTRACT
The abscisic acid-responsive gene rab17 of maize is expressed during late embryogenesis, and is induced by ABA and desiccation in embryo and vegetative tissues. ABRE and DRE cis-elements are involved in regulation of the gene by ABA and drought. Using yeast one-hybrid screening, we isolated two cDNAs encoding two new DRE-binding proteins, designated DBF1 and DBF2, that are members of the AP2/EREBP transcription factor family. Analysis of mRNA accumulation profiles showed that DBF1 is induced during maize embryogenesis and after desiccation, NaCl and ABA treatments in plant seedlings, whereas the DBF2 mRNA is not induced. DNA-binding preferences of DBFs were analysed by electrophoretic mobility shift assays, and showed that both DBF1 and DBF2 bound to the wild-type DRE2 element, but not to the DRE2 mutant or to the DRE1 element which differs only in a single nucleotide. Transactivation activity using particle bombardment showed that DBF1 functioned as activator of DRE2-dependent transcription of rab17 promoter by ABA, whereas DBF2 overexpression had a repression action downregulating not only the basal promoter activity, but also the ABA effect. These results show that ABA plays a role in the regulation of DBF activity, and suggests the existence of an ABA-dependent pathway for the regulation of genes through the C-repeat/DRE element.
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Banco de datos:
MEDLINE
Asunto principal:
Proteínas de Plantas
/
Agua
/
Ácido Abscísico
/
Estructuras de las Plantas
/
Zea mays
/
Proteínas de Arabidopsis
/
Proteínas de Unión al ADN
Idioma:
En
Revista:
Plant J
Asunto de la revista:
BIOLOGIA MOLECULAR
/
BOTANICA
Año:
2002
Tipo del documento:
Article
País de afiliación:
España