Institute of Molecular and Cellular Biology of Rosario (IBR)
MicroRNAs are essential endogenous regulators of gene expression in plants. They are generated from foldback precursors by the microprocessor, whose main component is DICER-LIKE1. The mature miRNAs of ~21 nt length are incorporated into ARGONAUTE complexes, which they then guide to target mRNAs that are subsequently cleaved or translationally arrested. In contrast to their stereotypical animal counterparts, plant microRNA precursors are very heterogeneous in size and shape. We have discovered that plant microRNAs can be generated by several different modes, explaining the variability of precursors that can generate these small RNAs.
Many evolutionarily conserved plant microRNAs regulate transcription factors involved in plant development. MicroRNA miR396 regulates GROWTH-REGUALTING FACTORS (GRFs), which are plant-specific transcription factors. The microRNA miR396-GRF module has been implicated in the promotion of organ growth and as a regulator of crop yield. We have been studying the integration of the miR396 regulatory network in the developmental program of the plant. Interestingly, while miR396 regulates cell proliferation in leaves, in the root apical meristem it aids to control and maintain the stem cell population. A general view of the microRNA biogenesis pathway, as well as the roles of the miR396 regulatory network will be presented.
Genome editing, cutting-edge technology for a sustainable agriculture