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

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

Puerto Madryn, Chubut

Encuentro; XLVI Reunión Anual - Sociedad Argentina de Investigación en Bioquímica y Biología Molecular; 2010

Sociedad Argentina de Investigación en Bioquímica y Biología Molecular

MicroRNAs (miRNAs) are small RNA molecules of ~21 nt. that arekey regulators of gene expression in multicellular organisms. Inplants, miRNAs have been implicated in diverse biologicalprocesses such as development, hormone signaling, and pathogenand stress responses. They recognize target RNAs through basecomplementarity and guide them to cleavage or translational arrest.Around 200 miRNA-encoding genes have been identified inArabidopsis which can be grouped into 86 families that give rise toidentical or almost identical mature miRNAs. The conservedmiR319 family is comprised of three members that regulate fiveTCP transcription factors (TCP2, 3, 4, 10 & 24) which have beeninvolved in the control of cell proliferation and differentiation. Inour present work we set on studying the role of the miR319/TCPregulatory network in Arabidopsis leaf and root development. Forthis, we analyzed cell and organ morphology of wild-type andmutant lines through DIC and laser scanning confocal microscopy, as well as, determining the expression profile of the systemcomponents. We found that plants with decreased levels of TCPsshowed bigger leaves and this was due to a change in cell proliferation. Also, increased levels of TCPs were detrimental forproper root organogenesis. The role of the miR319 regulatorynetwork in Arabidopsis development will be discussed.