CONICET | Buscador de Institutos y Recursos Humanos

Phaseolus vulgaris is an agronomical important legume thatestablishes a nitrogen-fixing symbiosis with Rhizobium etli. In thisinteraction, bacteria infect the root to reach the nodule, a post-embryonicorgan formed by division of cortical cells. A previous study from ourlaboratory showed that the C1 subunit of the plant nuclear factor NF-Y is a keyregulator of infection and nodule organogenesis. In order to identify otherfactors involved in this signaling pathway, a yeast two hybrid screening wasperformed. One of the positives clones encodes a protein kinase with atransmembrane domain at the N-terminus. The interaction has been confirmed byboth co-immunoprecipitation and bimolecular fluorescence complementation. Theprotein is distributed between the plasma membrane and the cytoplasm.Post-transcriptional silencing of the kinase by RNAi led to a reduction in thenumber and size of nodules and affected the infection thread formation in P.vulgaris roots. Interestingly, partner selection between high- and low-quality symbiotic partners was also affected in coinoculation experiments.Taken together, these results suggest that this gene is required for rhizobialinfection, nodule organogenesis and the molecular mechanism underlyingbacterial strain preference.