Nitrogen-Fixing Nodules Are an Important Source of Reduced Sulfur, Which Triggers Global Changes in Sulfur Metabolism in Lotus japonicus.
Plant Cell
; 27(9): 2384-400, 2015 Sep.
Article
em En
| MEDLINE
| ID: mdl-26296963
ABSTRACT
We combined transcriptomic and biochemical approaches to study rhizobial and plant sulfur (S) metabolism in nitrogen (N) fixing nodules (Fix(+)) of Lotus japonicus, as well as the link of S-metabolism to symbiotic nitrogen fixation and the effect of nodules on whole-plant S-partitioning and metabolism. Our data reveal that N-fixing nodules are thiol-rich organs. Their high adenosine 5'-phosphosulfate reductase activity and strong (35)S-flux into cysteine and its metabolites, in combination with the transcriptional upregulation of several rhizobial and plant genes involved in S-assimilation, highlight the function of nodules as an important site of S-assimilation. The higher thiol content observed in nonsymbiotic organs of N-fixing plants in comparison to uninoculated plants could not be attributed to local biosynthesis, indicating that nodules are an important source of reduced S for the plant, which triggers whole-plant reprogramming of S-metabolism. Enhanced thiol biosynthesis in nodules and their impact on the whole-plant S-economy are dampened in plants nodulated by Fix(-) mutant rhizobia, which in most respects metabolically resemble uninoculated plants, indicating a strong interdependency between N-fixation and S-assimilation.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Enxofre
/
Nódulos Radiculares de Plantas
/
Lotus
Idioma:
En
Revista:
Plant Cell
Assunto da revista:
BOTANICA
Ano de publicação:
2015
Tipo de documento:
Article
País de afiliação:
Grécia