title: Characterization of a rice (Oryza sativa L.) mutant deficient in the heme domain of nitrate reductase.
abstract: Biochemical and genetical characterization of a rice nitrate reductase (NR)-deficient mutant, M819, which had been isolated as a chlorate-resistant mutant, was carried out. In M819, leaf NADH-NR activity was found to be about 10% of that of the wild-type cv 'Norin 8', while NADPH-NR activity was higher than that in the wild-type; FMNH2-NR and MV-NR activities were also 10% of those of the wild type; BPB-NR activity was higher than that of the wild type; and xanthine dehydrogenase activity was revealed to be present in both. These results suggest that the mutant line M819 lacks the functional heme domain of the NADH-NR polypeptide due to a point mutation or a small deletion within the coding region of the structural gene. Chlorate resistance in M819 was transmitted by a single recessive nuclear gene.
authors.affiliation: Research Institute for Advanced Science and Technology, Shinke-cho, Sakai, 593, Osaka, Japan.
authors.forename: H
authors.initials: H
authors.lastname: Hasegawa
authors.forename: T
authors.initials: T
authors.lastname: Katagiri
authors.forename: S
authors.initials: S
authors.lastname: Ida
authors.forename: O
authors.initials: O
authors.lastname: Yatou
authors.forename: M
authors.initials: M
authors.lastname: Ichii