INSTITUTO DE BIOTECNOLOGIA Y BIOLOGIA MOLECULAR
Unidad Ejecutora - UE
congresos y reuniones científicas
Symbiotic Interaction Between Phaseolus vulgaris and rhizobia
O. MARIO AGUILAR; JOAQUIN CLUA; MARÍA EUGENIA ZANETTI; VIRGINIA DALLA VIA; CAROLINA RÍPODAS; GIL SERRANO A; MELISSE CASTAINGTS; FLAVIO BLANCO; MEGIAS M
Congreso; XXVII Reunión Latinoamericana de Rizobiología; 2016
Common bean (Phaseolus vulgaris) symbiotically associates with its partner Rhizobium etli, resulting in theformation of root nitrogen-fixing nodules, and it is preferentially nodulatedby R. etli strains from the samegeographical region of host domestication, namely the Mesoamerican and SouthAndean regions respectively. We have made use of this compatibility that becameestablished after coevolution between host and rhizobia in the same region toexamine the basis of the interaction. It is known that common bean is able toestablish effective symbiosis with a diversity of rhizobial phylotypes thatproduce different Nod factors. In order to assess if acetylfucosylation of theNod factor was important for the nodulation preference between lineages of R. etli and beans from the same regionof diversification, competitiveness assays were performed with a mixture ofstrains that produce Nod factor with and without the acetyl-group at thefucosyl site. Using transcriptional profiling of roots inoculated with mutantstrains defective in the synthesis of Nod Factor (NF), exopolysaccharide (EPS),or lipopolysaccharide (LPS), we identified 2,606 genes from common bean thatare differentially regulated at early stages of its interaction with Rhizobium etli. Many transcriptionfactors from different families are modulated by NF, EPS, and LPS in differentcombinations, suggesting that the plant response depends on the integration ofmultiple signals.Results showing the phenotypic and molecularcharacterization of genes expressed in the common bean-rhizobia earlyinteraction will be presented.