Tumour genes in plants: T-DNA encoded cytokinin biosynthesis

I Buchmann, F J Marner, G Schröder, S Waffenschmidt, J Schröder

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.

Original languageEnglish
JournalThe EMBO journal
Volume4
Issue number4
Pages (from-to)853-9
Number of pages7
ISSN0261-4189
Publication statusPublished - 04.1985

Fingerprint

Dive into the research topics of 'Tumour genes in plants: T-DNA encoded cytokinin biosynthesis'. Together they form a unique fingerprint.

Cite this