@article{mbs:/content/journal/micro/10.1099/00221287-129-8-2531, author = "Singh, Rama K. and Singh, Ramesh K. and Singh, Brahma D.", title = "Transfer of Nitrate Reductase Genes of the Cyanobacterium Nostoc muscorum into Rhizobium japonicum", journal= "Microbiology", year = "1983", volume = "129", number = "8", pages = "2531-2534", doi = "https://doi.org/10.1099/00221287-129-8-2531", url = "https://www.microbiologyresearch.org/content/journal/micro/10.1099/00221287-129-8-2531", publisher = "Microbiology Society", issn = "1465-2080", type = "Journal Article", abstract = "Transformation of Rhizobium japonicum CB1809 was studied using DNA from the cyanobacterium Nostoc muscorum ATCC 27893. A spontaneous nitrate reductase deficient (Nar−) mutant (NR-6) of R. japonicum CB1809 was isolated with a frequency of 8·4 × 10−7. Streptomycin (Sm) and Neomycin (Neo) resistance markers were introduced into strain NR-6, and the resulting strain was designated NR-6 SmR NeoR. Experiments with cyanobacterial DNA and live cells of strain NR-6 SmR NeoR indicated transformation of nitrate reductase (nar) genes of N. muscorum into this strain. This conclusion was supported by the reversion frequency of strain NR-6 SmR NeoR to Nar+ and the transformation frequency when recipient cells were exposed to N. muscorum DNA (with heat-treated DNA as control). Comparisons of growth, nitrate uptake, assimilatory nitrate reductase activity and nodulation of parent CB1809, NR-6 SmR NeoR and five transformant clones (Nar+) suggest that there may be considerable homology between the nar genes of R. japonicum CB1809 and N. muscorum. ", }