Tumour genes in plants: T-DNA encoded cytokinin biosynthesis.
EMBO J
; 4(4): 853-9, 1985 Apr.
Article
em En
| MEDLINE
| ID: mdl-15938044
ABSTRACT
Gene 4 from the T-region of Ti plasmids is responsible for cytokinin effects in crown gall cells; we investigated whether it codes for an enzyme of hormone biosynthesis. In a first set of experiments, gene 4 from octopine plasmid pTiAch5 and nopaline plasmid pTiC58 was expressed in Escherichia coli, and the gene products were identified by reaction with antiserum raised against a decapeptide derived from the DNA sequence of the gene. Extracts from cells expressing the gene contained high isopentenyl-transferase activity catalyzing the formation of N6-(delta2-isopentenyl)adenosine from 5'-AMP and delta2-isopentenylpyrophosphate. The cytokinin was identified by sequential h.p.l.c. chromatography and mass spectrometry. In a second set of experiments it was shown that crown gall cells contained isopentenyltransferase activity and a protein of mol. wt. 27 000 which was identified as the product of gene 4 by reaction with the antiserum. Isopentenyltransferase activity was specifically inhibited by the antiserum. No comparable enzyme activity or immunoreactive protein was detected in cytokinin-autotrophic, T-DNA free tobacco cells. The results establish that gene 4 from the T-region of octopine and nopaline Ti plasmids codes for an enzyme of cytokinin biosynthesis.
Texto completo:
1
Base de dados:
MEDLINE
Assunto principal:
Tumores de Planta
/
Genes de Plantas
/
DNA de Plantas
/
Citocininas
Idioma:
En
Revista:
EMBO J
Ano de publicação:
1985
Tipo de documento:
Article