INSTITUTO DE BIOTECNOLOGIA Y BIOLOGIA MOLECULAR
Unidad Ejecutora - UE
congresos y reuniones científicas
THE TIGHT-ADHESION PROTEIN TadG OF BRADYRHIZOBIUM JAPONICUM IS INVOLVED IN ADHESION AND INFECTIVITY ON SOYBEAN ROOTS
MONGIARDINI, E.J.; PARISI, G.; PÉREZ GIMÉNEZ, J.; LODEIRO, A.R.
Congreso; Rhizosphere 3; 2011
Aims and BackgroundAdhesion of Bradyrhizobium japonicum to soybean roots is required for rhizosphere colonization and root infection, and is mediated by bacterial adhesins. Among them are Tad (t ight adhesion) proteins, w hich were studied in other bacteria but not in rhizobia. We addressed a bioinformatic and molecular study of tadG in B. japonicum USDA 110.MethodsE volutionary analysis was done with PHYLIP. Three-dimensional models were constructed with SOPMA, PredictProtein, JUFO, MODELLER, and ITASSER. tadG was deleted in USDA 110 by replac ement with a kanamycin-resistance cassette. Adhesion and infectivity were studied as described (1).ResultsThe ORF blr3941 encodes TadG, which is implicated in the processing and transporting of Flppili. TadG has N-terminal and C-terminal domains separated by a 15-aminoacid transmembrane region. The C-terminal domain is homologous to integrin α1β1 family, and contains a von Willebrand fold, w hich is related w ith cell adhesion and recognition. B. japonicum USDA 110 and the blr3941 deletion mutant adhered to roots in clusters of 4-7 cells but adhesion of mutant w as 50% lower. Accordingly, mutant infectivity diminished by 67%. ConclusionThe ORF blr3941 encodes TadG, which is inv olved in B. japonicum adhesion and infectivity on soybean roots.