Dynamic regulation of cytoplasmic mRNAs during root nodule symbiosis

TRAUBENIK, SOLEDAD; BUSTOS-SANMAMED, PILAR; ZANETTI, MARÍA EUGENIA; HOBECKER, KAREN; BLANCO, FLAVIO; REYNOSO, MAURICIO; CRESPI, MARTÍN

Texas

Congreso; Plant Biology 2016; 2016

Dynamic regulation of cytoplasmic mRNAs during root nodule symbiosisSoledad Traubenik1, Mauricio Reynoso1?, Karen Hobecker1?, Pilar Bustos-Sanmamed2, Martín Crespi2, Flavio Blanco1 and María Eugenia Zanetti1*1Instituto de Biotecnología y Biología Molecular, Facultad de Ciencias Exactas-Universidad Nacional de La Plata and CCT La Plata-CONICET, Argentina. 2Institut des Sciences du Végétal, CNRS, Gif sur Yvette, France. *E -mail: ezanetti@biol.unlp.edu.ar?These authors contributed equally.Regulation of gene expression occurs at multiple levels within eukaryotic cells, including chromatin-based, transcriptional and post-transcriptional events. We have previously shown that genes involved in the legume root symbiosis are regulated at the level of their association with the translation machinery (1). Here, we used Translating Ribosome Affinity Purification (TRAP) (2) combined with RNA-sequencing (RNA-seq) to characterize RNA populations associated to polysomes (referred as the translatome). The characterization of dynamic changes in the translatome of Medicago truncatula roots at early stages of the root nodule symbiosis led us to the identification of mRNAs that significantly increased or decreased their levels of association with polysomes, some of which play essential roles in nodulation (e.g., pectate lyase, SINA and NCR secreted peptides). We have also identified a group of genes either up- or down-regulated at the translational level that participate in pre-mRNA splicing, 3´-processing of the pre-RNA, RNA-mediated post-transcriptional gene silencing, miRNA-mediated repression, mRNA turnover, epigenetic and transcriptional regulation. A number of long noncoding RNAs (lncRNAs) that changes their association to polysomes in response to rhizobia were also identified, suggesting that lncRNAs might act regulating the translation of their target genes. Functional characterization of these mRNAs and lncRNAs will reveal their role during early stages of the root nodule symbiosis.