CONICET | Buscador de Institutos y Recursos Humanos

The nitrogen-fixing symbiosis established between legumes and rhizobia involves the reprogramming of root cells. The association of RNAs to the translational machinery is a regulatory mechanism that contributes to this reprogramming of roots cells for symbiosis. We have previously shown that genes with key roles in the root nodule symbiosis between Medicago truncatula and Sinhorihizobium meliloti are regulated at the translational level. The high throughput characterization of RNAs associated to the translational machinery by RNA-seq led us to identify mRNAs and long non-coding RNAs (lncRNAs) that change their association to polysomes in response to rhizobial infection. These lncRNAs, which are associated with the translational machinery, may act repressing or activating the translation of its mRNA targets or encode functional small peptides that contribute to the reprogramming of root cells for the symbiotic interaction. We have focused on the biological characterization of one of such lncRNA Medtr3NC32155 that decreases its association to the translational machinery. Knockdown of lncRNA Medtr3NC32155 caused a significant reduction in the number of nodules, as well as affected in the frequency and progression of infection events. These results indicate that Medtr3NC32155 plays a function in the infection process required for the development of functional nodules. This analysis illustrates how the analysis of translational regulation can help to identify genes with crucial biological functions during morphogenetic processes such as the development of nitrogen-fixing nodules. The results will allow a better understanding of the biological phenomenon that leads to the biological nitrogen-fixation and transfer this information to programs for the improvement of relevant agronomic traits.