Mutation Research, 234 (1990) 369-432 Elsevier



European Environmental Selected Abstracts

of the 19th Annual 21-26

Edited by: A. Kappas



Mutagen Society

of the European




October 1989, Rhodes (Greece)

U. Ehling (Germany)

and A.T Natarajan

(The Netherlands)

(Received 12 March 1990) (Accepted 12 March 1990)


European Environmental Mutagen Society; Abstracts: Annual Meeting 1989

New DNA repair activity in tobacco mediated the transfer of E. coli repair gene u&z


Angelis, K. I, J. B?iza I, R. Hhlova ‘, K. Kleibl *, G. Margison 2, M. Ondfej 3, J. Satava 1 and J. \Celeminsky, Institute_ of Experimental Botany, CSAV Prague ’ and C. Budgjovice 3 (Czechoslovakia) and Paterson Institute for Cancer Research, CRC, Manchester ’ (U.K.) The coding sequence (1.1 kb) of the E. coli gene ada has been recloned as a BamHl fragment into the pAS2034 plasmid to a dual 1,2 promotor having the NPTII gene for kanamycin resistance as a selectable marker. Several kanamycin-resistant plants were selected after the transfer of this plasmid into tobacco Nicotiana tabacum var. xanthi, using the leaf disc method in a triparental mating system with the Ti plasmid pGV3850. Three kanamycin-resistant tobacco clones were characterized in detail: the integration of ada sequences into plant DNA and their transcription were shown by means of Southern and Northern

Correspondence: Prof. A.T. Natarajan, Department of Radiation Genetics and Chemical Mutagenesis, State University of Leiden, Wassenaarseweg 72, P.O. Box 9503, 2300 AR Leiden (The Netherlands). 0165-1161/90/$03.50

hybridization. The activity of Ada protein (Ob-alkylguanine-DNA-alkyltransferase) was determined in an in vitro assay to be dependent on the amount of proteins in the extracts from the leaf protoplasts. Calluses and cells in suspension derived from these kanamycin-resistant clones were more resistant to the toxic action of methylnitrosourea (MNU) and taurine chloroethylnitrosourea (TCNU) than the parental nontransformed cells, but equally sensitive to the toxic action of methyl methanesulfonate (MMS). Both the ada sequences and the activity of Ada protein were absent in the parental nontransformed tobacco.

Uvr +-dependent typhimurium BaEun-Dn&na, M. AlaceviC, Biotechnology,




V., I. MatiC, Z. MatijaBeviC Faculty of Food Technology Zagreb (Yugoslavia)

and and

Exposure of Escherichia coli to non-toxic levels of MNNG induces the adaptive response which confers resistance to the killing and mutagenic effects of MNNG. The Ada protein plays a central role in the regulation of the adaptive response. The Salmonella typhimurium phenotype is comparable to the E. coli ada mutant in having a low,

0 1990 Elsevier Science Publishers B.V. (Biomedical Division)

Selected abstracts of the 19th annual meeting of the European Environmental Mutagen Society. 21-26 October 1989, Rhodes, Greece.

369 Mutation Research, 234 (1990) 369-432 Elsevier MUTENV 08759 European Environmental Selected Abstracts of the 19th Annual 21-26 Edited by: A...
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