title: Variant Cell Lines of Haplopappus gracilis with Disturbed Activities of Nitrate Reductase and Nitrite Reductase.
abstract: Selected variant cell lines of Haplopappus gracilis (Nutt) Gray that showed disturbed growth after transfer from an alanine medium to NO(3) (-) medium were characterized. The in vivo NO(3) (-) reductase activity (NRA) was lower in these lines than in the wild type. In vitro NRA assays suggest that decreased in vivo NRA was not caused by a lower amount of active enzyme. Cells of the variant lines revealed up to 75% lower extractable activity of NO(2) (-) reductase as compared with the wild type. This coincided with higher accumulation of NO(2) (-) by the variant than by the wild type cells after transfer from alanine medium to NO(3) (-) medium. NO(2) (-) accumulation was transient or continuous, depending on cell line, metabolic state of the cells, and light conditions.
authors: Research Institute ITAL, P. O. Box 48, 6700 AA Wageningen, The Netherlands.
authors: L J
authors: LJ
authors: Gilissen
authors: A J
authors: AJ
authors: Barneix
authors: M
authors: M
authors: van Staveren
authors: H
authors: H
authors: Breteler