title: Isolation of biochemical mutants using haploid mesophyll protosplasts of Hyoscyamus muticus : IV. Biochemical characterisation of nitrate non-utilizing clones.
abstract: Four nitrate non-utilizing clones of Hyoscyamus muticus, obtained by a total isolation method, possess all the known characteristics of cnx-type nitrate-reductase-deficient variants: 1) strict dependence on a reduced nitrogen source such as a mixture of amino acids; 2) chlorate resistance; 3) normal nitrate uptake; 4) lack of nitrate-reductase and xanthine-dehydrogenase activities, but presence of cytochrome-c-reductase and nitrite-reductase activities; 5) in vitro nitrate-reductase complementation with a molybdenum cofactor source. Two of the clones (MA-2 and I2D12) are molybdate repairable in vivo, whilst the other two clones (VIC2 and XIVE9) are not.
authors.affiliation: Friedrich Miescher-Institut, P.O. Box 2543, CH-4002, Basel, Switzerland.
authors.forename: H
authors.initials: H
authors.lastname: Fankhauser
authors.forename: F
authors.initials: F
authors.lastname: Bucher
authors.forename: P J
authors.initials: PJ
authors.lastname: King