IBBM   21076
INSTITUTO DE BIOTECNOLOGIA Y BIOLOGIA MOLECULAR
Unidad Ejecutora - UE
artículos
Título:
Sulfate modification of Rhizobium sp. LPU83 Nodulation factors signaling molecules is not necessaries for symbiosis with alfalfa (Medicago sativa)
Autor/es:
TORRES TEJERIZO, G.; DEL PAPA, M. F.; SORIA-DIAZ ,M. E; DRAGHI, W.O.; LOZANO, M.J.; GIUSTI ,M.A.; MANYANI, H.; MEGIAS, M; GIL SERRANO, A.; PÜHLER, A. ; KARSTEN, N.; LAGARES, A.; PISTORIO, M.
Revista:
JOURNAL OF BACTERIOLOGY
Editorial:
AMER SOC MICROBIOLOGY
Referencias:
Año: 2011 vol. 193 p. 30 - 39
ISSN:
0021-9193
Resumen:
The
induction of root nodules by the majority of rhizobia has a strict requirement
for the secretion of symbiosis-specific lipochitooligosaccharides (nodulation
factors [NFs]). The nature of the chemical substitution on the NFs depends on
the particular rhizobium and contributes to the host specificity imparted by
the NFs. We present here a description of the genetic organization of the nod gene cluster
and the characterization of the chemical structure of the NFs associated with
the broad-host-range Rhizobium sp. strain
LPU83, a bacterium capable of nodulating at least alfalfa, bean, and Leucena
leucocephala. The nod gene cluster
was located on the plasmid pLPU83b. The organization of the cluster showed
synteny with those of the alfalfanodulating rhizobia, Sinorhizobium
meliloti and Sinorhizobium medicae. Interestingly, the strongest sequence similarity
observed was between the partial nod sequences of
Rhizobium mongolense USDA 1844 and the corresponding LPU83 nod genes
sequences. The phylogenetic analysis of the intergenic region nodEG positions strain
LPU83 and the type strain R. mongolense 1844 in the same
branch, which indicates that Rhizobium sp. strain
LPU83 might represent an early alfalfa-nodulating genotype. The NF chemical
structures obtained for the wild-type strain consist of a trimeric, tetrameric,
and pentameric chitin backbone that shares some substitutions with both
alfalfa- and bean-nodulating rhizobia. Remarkably, while in strain LPU83 most
of the NFs were sulfated in their reducing terminal residue, none of the NFs
isolated from the nodH mutant LPU83-H were
sulfated. The evidence obtained supports the notion that the sulfate decoration
of NFs in LPU83 is not necessary for alfalfa nodulation.