Strana 1 od 104 výsledky
The activity and extent of adenylylation of glutamine synthetase was examined in both free-living and bacteroid forms of Rhizobium japonicum in the presence of excess ammonia. Ammonia caused an apparent repression of glutamine synthetase in free-living R. japonicum and adenylylation of the enzyme
Soybean (Glycine max) nodule bacteroids contain high concentrations of poly-beta-hydroxybutyrate and possess a depolymerase system that catalyzes the hydrolysis of the polymer. Changes in poly-beta-hydroxybutyrate content and in activities of nitrogenase, beta-hydroxybutyrate dehydrogenase, and
Soluble root N concentrations of corn, sorghum, pearl millet, rice, wild rice, and soybeans were determined and related to measurements of nitrogenase activity and changes in availability of combined N to plants. In corn, sorghum, and pearl millet, applications of fertilizer N increased soluble root
The nitrogenase system in cell-free extracts of soybean nodule bacteroids was fractionated into 2 components by use of protamine sulfate or polypropylene glycol precipitation followed by chromatography on DEAE-cellulose. Iron and molybdenum were concentrated in 1 fraction and iron in the other.
Bacteroids in ineffective (nitrogenase negative) nodules of Glycine max, infected with Rhizobium japonicum 61-A-24, as compared to those in effective nodules are characterized by reduced specific activities of alanine dehydrogenase to 15%, of 3-hydroxybutyrate dehydrogenase to 50%, and an increase
Nodulated soybean (Glycine max L. Merr. cv White Eye inoculated with Bradyrhizobium japonicum strain CB 1809) plants were cultured in the absence of combined N from 8 to 28 days with their root systems maintained continuously in 1, 2.5, 5, 10, 20, 40, 60, or 80% O(2) (volume/volume) in N(2). Plant
Nitrate or ammonium was added to soybean (Glycine max L. Merrill cv Corsoy) plants grown in plastic pouches 10 days after nodules first appeared. By the third day of treatment with 10 millimolar nitrate, nitrogenase specific activity (per unit nodule weight) had decreased to 15% to 25% of that of
Heat evolved by isolated soybean (Glycine max cv Clark) nodules was measured to estimate more directly the metabolic cost associated with the symbiotic N(2) fixation system. A calorimeter constructed by modifying standard laboratory equipment allowed measurement on 1 gram of detached nodules under a
A novel, pulse-modulated spectroscopic system for measuring fractional leghemoglobin oxygenation and infected cell O(2) concentration (O(i)) in intact attached nodules of soybean (Glycine max) is described. The system is noninvasive and uses a pulsed (1000 Hertz) light-emitting diode coupled to an
Soybean (Glycine max cv Hodgson) nitrogenase activity (C(2)H(2) reduction) in the presence or absence of nitrate was studied at various external O(2) tensions. Nitrogenase activity increased with oxygen partial pressure up to 30 kilopascals, which appeared to be the optimum. A parallel increase in
When suspension cultures of actively growing soybean (Glycine max L.) root cells were separated by two or three membrane filters from suspension cultures of the bacteria, a synergetic (cooperative) activation of nitrogenase was observed in the Rhizobium japonicum used in the bacterial side. Either
When intact nodulated roots of soybean (Glycine max L. Merr. nodulated with Bradyrhizobium japonicum strain USDA 16) were exposed to an atmosphere lacking N(2) gas (Ar:O(2) 80:20), total nitrogenase activity (measured as H(2) evolution) and respiration (CO(2) evolution) declined with time of
BACKGROUND AND AIMS The inner cortical cells (IC-cells) of legume root nodules have been previously shown to regulate the resistance to nodule O2 diffusion by a rapid contraction/expansion mechanism, which controls the volume of intercellular spaces and their occlusion by a liquid phase. The
The total metabolic cost of soybean (Glycine max L. Mer Clark) nodule nitrogen fixation was empirically separated into respiration associated with electron flow through nitrogenase and respiration associated with maintenance of nodule function.Rates of CO(2) evolution and H(2) evolution from intact,
Tungsten (W) finds increasing application in military, aviation and household appliance industry, opening new paths into the environment. Since W shares certain chemical properties with the essential plant micronutrient molybdenum (Mo), it is proposed to inhibit enzymatic activity of molybdoenzymes