IBBM   21076
INSTITUTO DE BIOTECNOLOGIA Y BIOLOGIA MOLECULAR
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
The microRNA390/TAS3 pathway controls symbiotic nodulation and lateral root growth in Medicago truncatula.
Autor/es:
MARIA EUGENIA ZANETTI
Lugar:
Rosario
Reunión:
Simposio; Simposio de Genómica Funcional de Plantas; 2017
Institución organizadora:
comité organizador del simposio
Resumen:
Legume roots form two types of postembryonic organs, lateral roots and symbiotic nodules. Nodule formation is the result of theinteraction of legumes with rhizobia and requires the mitotic activation and differentiation of root cells as well as an independent, butcoordinated, program that allows infection by rhizobia. MicroRNA390 (miR390) is an evolutionarily conserved microRNA thattargets the Trans-Acting Short Interference RNA3 (TAS3) transcript. Cleavage of TAS3 by ARGONAUTE7 results in the production oftrans-acting small interference RNAs, which target mRNAs encoding AUXIN RESPONSE FACTOR2 (ARF2), ARF3, and ARF4. Here,we show that activation of the miR390/TAS3 regulatory module by overexpression of miR390 in Medicago truncatula promotes lateralroot growth but prevents nodule organogenesis, rhizobial infection, and the induction of two key nodulation genes, NodulationSignaling Pathway1 (NSP1) and NSP2. Accordingly, inactivation of the miR390/TAS3 module, either by expression of a miR390target mimicry construct or mutations in ARGONAUTE7, enhances nodulation and rhizobial infection, alters the spatial distributionof the nodules, and increases the percentage of nodules with multiple meristems. Our results revealed a key role of the miR390/TAS3pathway in legumes as a modulator of lateral root organs, playing opposite roles in lateral root and nodule development.Plants adapt