NF-YC1, a transcription factor required for nodule organogenesis, interacts with a putative protein kinase

JOAQUÍN CLÚA, CAROLINA RÍPODAS, MARINA BATTAGLIA, MARÍA EUGENIA ZANETTI AND FLAVIO A. BLANCO

Portland

Congreso; Plant Biology 2014; 2014

American Society of Plant Biology (ASPB)

Common bean (Phaseolus vulgaris) establishes a nitrogen fixing association with its partner Rhizobium etli. In this interaction, host-dependant competitiveness has been observed, in which accessions from the Mesoamerican region are more efficient and preferentially nodulated by strains that are predominant in the same geographical region. A C subunit of the heterotrimeric nuclear factor Y (NF-Y), named NF-YC1, was identified as a gene required for nodule organogenesis and bacterial infection that contributes to this preferential association. In order to identify proteins that can physically interact with NF-YC1, a yeast two hybrid screening was performed using NF-YC1 as bait and a cDNA library from root tissue inoculated with R. etlias prey. A total of eight clones that potentially interacts with NF-YC1 were isolated.  Among them, one encodes a protein kinase (PK) with a putative transmembrane domain at the N-terminus. The bioinformatic analysis of the kinase domain indicates that it lacks two of the three conserved residues required for catalytic activity. Interaction of NF-YC1 with this PK has been confirmed by retransformation of yeast and in planta by bimolecular fluorescent complementation assays in Agrobacterium-infiltrated Nicotianabenthamiana leaves. Expression of a translational fusion PK-GFP suggests that it localizes to the cytoplasm and the plasma membrane. The function of this gene in nodulation efficiency and bacterial infection is being evaluated both by RNAi mediated-posttranscriptional gene silencing and ectopic expression in common bean roots. This study will contribute to elucidate the signal transduction pathway specifically activated in Mesoamerican common bean in response to its cognate R. etli strain.