Structural determination of Nod factors and Genetic variability of Symbiotic Genes in peanut rhizobia isolates from Argentina

TAURIAN, T., MEGIAS, M., MORÓN, B., GIL-SERRANO, A., SORIA, M.E., AGUILAR, O.M., FABRA, A.

Miguel Pereira, Río de Janeiro, Brasil

Conferencia; 22nd Latin-American Conference on Rhizobiology, 1st Brazilian Conference on Biological Nitrogen Fixation; 2004

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Abstract Structural determination of Nod factors and Genetic variability of Symbiotic Genes in peanut rhizobia isolates from Argentina In this work we examined the synthesis and structure of Nod factors and the genetic variability of symbiotic genes from slow-growing peanut nodulating rhizobia.  Although the importance of cultivating peanut in some countries, little is known about the genetic requirements for its symbiotic association with rhizobia. In particular, the Nod factors structure has not been yet identified. The aims of this study were to determine the Nod factors produced by peanut symbionts and to characterize several nod genes involved in the synthesis of these signal molecules.   In this study we demonstrated that although isolates NDEHE, NLH25 and NOD31 showed identical TLC profile of LCOs only NLH25 and NOD31 were able to nodulate common bean. Furthermore, even when the Nod factors elaborated by NDEHE and NGR234 are structurally similar, great differences in their host ranges were observed. These data suggest that it is not possible to establish a direct association between the structure of Nod factor synthetized and the legumes rhizobia are able to nodulate.