Abstract
Nineteen chlorate-resistant variants were isolated after mutagenesis from cells of Medicago coerulea. The level of nitrate reductase activity was variable in these lines and ranged from 100% to less than 5% of the wild type level. Xanthine dehydrogenase was not affected in any of those variants tested.
Methylammonium-resistant variants were also isolated from the same type of cells. They show a different regulation of nitrogen utilization. In particular, the enzymatic level of nitrate reductase which, in wild type cells, is sensitive to ammonium repression, is much less affected in the variants. Differences were also seen in the regulation of other functions of the nitrogen-utilizing pathway: xanthine dehydrogenase and, possibly, adenine uptake.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
Arst HN. Jr, Cove DJ (1969) J. Bacteriol 98: 1284–1293.
Dunn-Coleman NS, Smarrelli J. Jr, Garret RH (1984) Int. Rev. Cytol. 92:1–50.
Gamborg OL, Miller RA, Ojima K (1968) Exp. Cell. Res. 50:151–158.
Giuliano G, Lo Schiavo F, Terzi M (1984) Theor. Appl. Genet. 67:179–183.
Jacobsen E, Braaksma FJ, Feenstra WJ (1984) Z. Pflanzenphysiol 113:183–188.
Lo Schiavo F, Nuti Ronchi V, Terzi M (1980) Theor. Appl. Genet. 58:43–47.
Marton L, Dung TM, Mendel RR, Maliga P (1982) Mol. Gen. Genet. 182:301–304.
Mendel RR, Mueller AJ (1976) Biochem. Physiol. Pflanzen 170:538–541.
Mueller AJ, Grafe R (1978) Mol. Gen. Genet. 161:67–76.
Author information
Authors and Affiliations
Additional information
Communicated by P.J. King
on leave from EniChem SpA, Milan, Italy
Rights and permissions
About this article
Cite this article
Giuliano, G., Mita, G., Indiogine, S.E.P. et al. Medicago cell variants showing altered nitrogen utilization. Plant Cell Reports 5, 325–328 (1986). https://doi.org/10.1007/BF00268592
Received:
Revised:
Issue Date:
DOI: https://doi.org/10.1007/BF00268592