Premium
Different expression of an S ‐adenosylmethionine synthetase gene in transgenic tobacco callus modifies alkaloid biosynthesis
Author(s) -
Belbahri Lassaad,
Chevalier Laurence,
Bensaddek Lamine,
Gillet Françoise,
Fliniaux MarcAndré,
Boerjan Wout,
Inzé Dirk,
Thomas Daniel,
Thomasset Brigitte
Publication year - 2000
Publication title -
biotechnology and bioengineering
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.136
H-Index - 189
eISSN - 1097-0290
pISSN - 0006-3592
DOI - 10.1002/(sici)1097-0290(20000705)69:1<11::aid-bit2>3.0.co;2-j
Subject(s) - biosynthesis , alkaloid , callus , transgene , gene , genetically modified crops , gene expression , biochemistry , biology , chemistry , genetics , botany
Transformed callus cultures of Nicotiana tabacum were generated in which the SAM‐1 gene from Arabidopsis thaliana encoding S ‐adenosylmethionine synthetase (SAM‐S), under the control of the 35S promoter, had been integrated. The presence of the SAM‐1 gene was detected in all tested transformants and the SAM‐S activity correlated with the accumulation of SAM in the tobacco callus cultures. Three distinct phenotypic classes were identified among the transgenic cell lines in relation to growth of the cells, structure of the calli, and level of SAM. Transgene silencing was observed in several cultivated transgenic calli and this phenomenon was correlated directly with a low level of SAM‐1 mRNA accompanied by a decrease of the SAM‐S activity. The transgenic calli overexpressing the SAM‐1 gene accumulated a high SAM level. The modifications in SAM‐S activity were reflected in the pattern of secondary products pres‐ ent in the different cell lines, thereby demonstrating that the flux through the biosynthetic pathway of a plant secondary product can be modified by means of genetic engineering. © 2000 John Wiley & Sons, Inc. Biotechnol Bioeng 69: 11–20, 2000.