Phosphorous deficiency decreases nitrogenase activity but increases proton efflux in N2-fixing Medicago truncatula.
Plant Physiol Biochem
; 49(4): 458-60, 2011 Apr.
Article
em En
| MEDLINE
| ID: mdl-21334214
ABSTRACT
Effects of Sinorhizobium strain and P nutrition on N(2)-dependent growth, nitrogenase activity and proton efflux by nodulated roots were investigated in the model legume Medicago truncatula cultivar Jemalong grown in hydroaeroponic culture in symbioses with Sinorhizobium meliloti strains 102F51 and 2011. Sinorhizobium strain had strong effects on nitrogenase activity and N(2)-dependent growth, with S. meliloti 102F51 being the more efficient strain. Apparent and total nitrogenase activities, measured by hydrogen evolution in air and argon, respectively, were drastically reduced in plants supplied with 5 µmol P plant(-1) week(-1) as compared with 15 µmol P plant(-1) week(-1). There was a net proton efflux as soon as 2 weeks after inoculation and, in contrast to the effect of P nutrition on nitrogenase activity, P deficiency increased total and specific proton effluxes, irrespective of Sinorhizobium strain.
Texto completo:
1
Base de dados:
MEDLINE
Assunto principal:
Fósforo
/
Prótons
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Sinorhizobium meliloti
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Medicago truncatula
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Nódulos Radiculares de Plantas
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Fixação de Nitrogênio
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Nitrogenase
Idioma:
En
Revista:
Plant Physiol Biochem
Ano de publicação:
2011
Tipo de documento:
Article
País de afiliação:
Alemanha