title: Nitrogen Fixation in French-beans in the Presence of Nitrate: Effect on Bacteroid Respiration and Comparison with Nitrite.
abstract: Bacteroids isolated from French-bean (Phaseolus vulgaris L.) nodules exhibited a limited C(2)H(2) reduction activity, associated with a decline in their respiration rate, when the plants were previously fed for 24 h with a 3.5 mM Ca(NO(3))(2) solution. Similar effects were observed when bacteroid incubations received increasing nitrite concentrations. The level of cyt-c reduction recorded by a rapid spectrometric technique was increased by 15 to 20 % for bacteroids isolated from plants receiving nitrate or when N0(2)(-) was added to incubations. At the bacteroid level, the close analogy between the effects observed after supplying legumes with nitrate and the direct addition of nitrite suggested the involvement of nitrite in the inhibition of nitrogen fixation.
authors.affiliation: Laboratoire de Biologie végétale, Faculté des Sciences et des Techniques, Parc Valrose, 06034 Nice Cedex, France.
authors.forename: J C
authors.initials: JC
authors.lastname: Trinchant
authors.forename: J
authors.initials: J
authors.lastname: Rigaud