Dynamic regulation of the Medicago truncatula translatome mediated by long non-coding RNAs during root nodule symbiosis

TRAUBENIK, SOLEDAD; REYNOSO, MAURICIO; ROSE, B; TOWN, C; BLANCO, FLAVIO; ZANETTI, MARÍA EUGENIA

Buenos Aires

Congreso; XVIII Jornadas Anuales Interdisciplinarias Sociedad Argentina de Biología; 2016

DYNAMIC REGULATION OF THE MEDICAGO TRUNCATULA TRANSLATOME MEDIATED BY LONG NON-CODING RNAs DURING ROOT NODULE SYMBIOSISTraubenik S1, Reynoso M1, 2, Rose B3, Town C3, Blanco F1, Zanetti M E1. 1IBBM, FCE-UNLP CCT-CONICET, Argentina. 2Center for Plant Cell Biology, University of California, USA. 3J. Craig Venter Institute, Rockville, MD, USA. E-mail:soledadtraubenik@biol.unlp.edu.arThe development of transcriptomic techniques has led to the use of steady-state levels of mRNAs as a criterion to select and study genes in the context of a biological process. This approach has excluded levels of post-transcriptional regulation, such as the rapid response through the translational activation of mRNAs. We have shown that genes involved in the root nodule symbiosis are regulated at the level of their association with the translation machinery. Here, we used Translating Ribosome Affinity Purification (TRAP) combined with RNA-sequencing to characterize the populations of mRNAs and non-coding RNAs associated to polysomes (referred to as the translatome). The characterization of dynamic changes in the translatome of M. truncatula at early stages of the root nodule symbiosis led us to the identification of mRNAs that significantly change their levels of association with polysomes in response to rhizobia. Some of these mRNAs play essential roles in nodulation (e.g., NIN, NF-YA,, pectate lyase, SINA and NCR peptides). We have also identified a group of mRNAs that are either up- or down-regulated at the translational level, which encode proteins that participate in epigenetic and post-transcriptional regulation (a Superkiller-like protein, a DNA methylase, a CCR4-NOT subunit and a La-related protein). In addition, we identified a significant number of lncRNAs that change their association with polysomes in response to rhizobial infection. These lncRNAs might act either repressing or activating the translation of other mRNAs or they might encode functional small peptides (as described in mammals). These changes in the translatome might contribute to the reprogramming of root cells during early stages of the symbiotic interaction.