Complementation analysis of nitrate reductase deficient mutants of Nicotiana tabacum by somatic hybridization
Grafe, R.; Müller, A.J.
Tag. Theoretical and Applied Genetics. Theoretische und Angewandte Genetik 66(2): 127-130
1983
ISSN/ISBN: 0040-5752 PMID: 24263765 DOI: 10.1007/bf00265186
Accession: 005019962
Mutant cell lines lacking nitrate reductase activity were analyzed genetically. Protoplasts from one apoprotein defective (nia) and four cofactor defective (cnx) mutants were fused in all possible pairwise combinations with the aid of polyethylene glycol. Complementing hybrids were detected by their ability to grow with nitrate as sole nitrogen source and confirmed by measuring their nitrate reductase activity. Strong complementation was observed in all types of nia+cnx hybrids, whereas the cnx mutants failed to complement each other. From the results it can be concluded that the mutants studied are recessive and that the four cnx mutants are alleles of the same pair of duplicate loci (cnxA1, cnxA2).