Glutamate is involved in acid stress response in Bradyrhizobium sp. SEMIA 6144 (Arachis hypogaea L.) microsymbiont.
In the present study, the effect of acid stress on ammonium assimilation in Bradyrhizobium sp. SEMIA 6144 (Arachis hypogaea L.) microsymbiont was analyzed. The bacterial growth rate was decreased by 50%, and a significant increase in intracellular glutamate concentration was detected when the strain grew at acid pH (5.5). Assays of the enzymes involved in glutamate synthesis showed increased activities of glutamine synthetase (GS) and glutamate synthase (NADPH-GOGAT) under acid stress condition. This would support the contention that the GS/NADPH-GOGAT pathway contributes to the increase of glutamate synthesis as a compatible solute in response to acid stress.
Natera
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Departamento de Ciencias Naturales, Facultad de Ciencias Exactas, FísicoQuímicas y Naturales, Universidad Nacional de Río Cuarto, Ruta 36 Km 601, 5800, Río Cuarto, Córdoba, Argentina.
Sobrevals
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Fabra
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A
Castro
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S
D000143:Acids; D010367:Arachis / Q000382:microbiology*; D020369:Bradyrhizobium / Q000254:growth & development / Q000378:metabolism*; D050790:Glutamate Synthase (NADH) / Q000378:metabolism; D005974:Glutamate-Ammonia Ligase / Q000378:metabolism; D018698:Glutamic Acid / Q000378:metabolism*; D006863:Hydrogen-Ion Concentration; D000644:Quaternary Ammonium Compounds / Q000378:metabolism; D015398:Signal Transduction; D013559:Symbiosis
D000143:Acids; D000644:Quaternary Ammonium Compounds; D018698:Glutamic Acid; D050790:Glutamate Synthase (NADH); D005974:Glutamate-Ammonia Ligase