INVESTIGADORES
DARDANELLI Marta Susana
artículos
Título:
Different and new Nod factors identified after increased biosynthesis in Rhizobium tropici CIAT899 following Na+ stress
Autor/es:
ESTÉVEZ J., SORIA-DÍAZ M.E., FERNÁNDEZ DE CÓRDOBA F., MORÓN B., MANYANI H., GIL A., THOMAS-OATES J., VAN BRUSSEL A.A.N., DARDANELLI M.S., SOUSA C AND MEGIAS M.
Revista:
FEMS MICROBIOLOGY LETTERS
Editorial:
Blackwell Publishing
Referencias:
Año: 2009 vol. 293 p. 220 - 231
ISSN:
0378-1097
Resumen:
The root nodule bacterium Rhizobium tropici strain CIAT899 is highly stress
resistant. It grows under acid conditions, in large amounts of salt, and at high
osmotic pressure. An earlier study reported a substantial qualitative and quantitative
effect of acid stress on the biosynthesis of Nod factors. The aim of the present
work was to investigate the effect of high salt (NaCl) concentrations, another
common stress factor, on Nod factor production. For this purpose, thin-layer
chromatography, HPLC and MS analyses were carried out. The expression of
nodulation genes was also studied using a nodP<lacZ fusion. High concentrations
of sodium enhanced nod gene expression and Nod factor biosynthesis. The effect is
sodium specific because high potassium or chloride concentrations did not have
this effect. Under salt stress conditions, 46 different Nod factors were identified in a
CIAT899 culture, compared with 29 different Nod factors under control conditions.
Only 15 Nod factor structures were common to both conditions. Under salt
stress conditions, 14 different new Nod factor structures were identified that were
not observed as being produced under neutral or acid conditions. The implications
of our results are that stress has a great influence on Nod factor biosynthesis
and that new, very interesting regulatory mechanisms, worth investigating, are
involved in controlling Nod factor biosynthesis.Rhizobium tropici strain CIAT899 is highly stress
resistant. It grows under acid conditions, in large amounts of salt, and at high
osmotic pressure. An earlier study reported a substantial qualitative and quantitative
effect of acid stress on the biosynthesis of Nod factors. The aim of the present
work was to investigate the effect of high salt (NaCl) concentrations, another
common stress factor, on Nod factor production. For this purpose, thin-layer
chromatography, HPLC and MS analyses were carried out. The expression of
nodulation genes was also studied using a nodP<lacZ fusion. High concentrations
of sodium enhanced nod gene expression and Nod factor biosynthesis. The effect is
sodium specific because high potassium or chloride concentrations did not have
this effect. Under salt stress conditions, 46 different Nod factors were identified in a
CIAT899 culture, compared with 29 different Nod factors under control conditions.
Only 15 Nod factor structures were common to both conditions. Under salt
stress conditions, 14 different new Nod factor structures were identified that were
not observed as being produced under neutral or acid conditions. The implications
of our results are that stress has a great influence on Nod factor biosynthesis
and that new, very interesting regulatory mechanisms, worth investigating, are
involved in controlling Nod factor biosynthesis.nodP<lacZ fusion. High concentrations
of sodium enhanced nod gene expression and Nod factor biosynthesis. The effect is
sodium specific because high potassium or chloride concentrations did not have
this effect. Under salt stress conditions, 46 different Nod factors were identified in a
CIAT899 culture, compared with 29 different Nod factors under control conditions.
Only 15 Nod factor structures were common to both conditions. Under salt
stress conditions, 14 different new Nod factor structures were identified that were
not observed as being produced under neutral or acid conditions. The implications
of our results are that stress has a great influence on Nod factor biosynthesis
and that new, very interesting regulatory mechanisms, worth investigating, are
involved in controlling Nod factor biosynthesis.nod gene expression and Nod factor biosynthesis. The effect is
sodium specific because high potassium or chloride concentrations did not have
this effect. Under salt stress conditions, 46 different Nod factors were identified in a
CIAT899 culture, compared with 29 different Nod factors under control conditions.
Only 15 Nod factor structures were common to both conditions. Under salt
stress conditions, 14 different new Nod factor structures were identified that were
not observed as being produced under neutral or acid conditions. The implications
of our results are that stress has a great influence on Nod factor biosynthesis
and that new, very interesting regulatory mechanisms, worth investigating, are
involved in controlling Nod factor biosynthesis.