The maize auxotrophic mutant orange pericarp is defective in duplicate genes for tryptophan synthase beta.
Plant Cell
; 4(6): 711-9, 1992 Jun.
Article
en En
| MEDLINE
| ID: mdl-1356534
orange pericarp (orp) is a seedling lethal mutant of maize caused by mutations in the duplicate unlinked recessive loci orp1 and orp2. Mutant seedlings accumulate two tryptophan precursors, anthranilate and indole, suggesting a block in tryptophan biosynthesis. Results from feeding studies and enzyme assays indicate that the orp mutant is defective in tryptophan synthase beta activity. Thus, orp is one of only a few amino acid auxotrophic mutants to be characterized in plants. Two genes encoding tryptophan synthase beta were isolated from maize and sequenced. Both genes encode polypeptides with high homology to tryptophan synthase beta enzymes from other organisms. The cloned genes were mapped by restriction fragment length polymorphism analysis to approximately the same chromosomal locations as the genetically mapped factors orp1 and orp2. RNA analysis indicates that both genes are expressed in all tissues examined from normal plants. Together, the biochemical, genetic, and molecular data verify the identity of orp1 and orp2 as duplicate structural genes for the beta subunit of tryptophan synthase.
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Triptófano Sintasa
/
Familia de Multigenes
/
Zea mays
/
Mutación
Idioma:
En
Revista:
Plant Cell
Asunto de la revista:
BOTANICA
Año:
1992
Tipo del documento:
Article
Pais de publicación:
Reino Unido