ROLE OF THE MIR319/TCP REGULATORY NETWORK DURING THE DEVELOPMENT OF Arabidopsis thaliana

BRESSO, EDGARDO G; RODRIGUEZ, RAMIRO ESTEBAN; PALATNIK, JAVIER F; SCHOMMER, CARLA

Pto Madryn

Congreso; XLVI Reunión Anual de la Sociedad Argentina de Investigaciones en Bioquímica y Biología Molecular; 2010

MicroRNAs (miRNAs) are small RNA molecules of ~21 nt. that are key regulators of gene expression in multicellular organisms. In plants, miRNAs have been implicated in diverse biological processes such as development, hormone signaling, and pathogen and stress responses. They recognize target RNAs through base complementarity and guide them to cleavage or translational arrest. Around 200 miRNA-encoding genes have been identified in Arabidopsis which can be grouped into 86 families that give rise to identical or almost identical mature miRNAs. The conserved miR319 family is comprised of three members that regulate five TCP transcription factors (TCP2, 3, 4, 10 & 24) which have been involved in the control of cell proliferation and differentiation. In our present work we set on studying the role of the miR319/TCP regulatory network in Arabidopsis leaf and root development. For this, we analyzed cell and organ morphology of wild-type and mutant lines through DIC and laser scanning confocal microscopy, as well as, determining the expression profile of the system components. We found that plants with decreased levels of TCPs showed bigger leaves and this was due to a change in cell proliferation. Also, increased levels of TCPs were detrimental for proper root organogenesis. The role of the miR319 regulatory network in Arabidopsis development will be discussed.