CONTROL OF BIOLOGICAL PATHWAYS BY microRNAs IN PLANTS.

RAMIRO ESTEBAN RODRIGUEZ VIRASORO; DETLEF WEIGEL; JAVIER PALATNIK

Pinamar, Buenos Aires, Argentina

Congreso; XLI Reunión Anual Nacional de la Sociedad Argentina de Investigaciones en Bioquímica y Biología Molecular; 2005

MicroRNAs (miRNAs) have been recently recognized as a novel mechanism to regulate gene expression. They are small RNAs of 18 to 21 nucleotides in length that recognize partially complementary sequences in target mRNAs and guide them to cleavage or translational arrest. They are encoded as long precursors with fold‑back structures by small gene families. In plants, they have been implicated in many key processes such as development and stress responses. Currently, we are characterizing several plant miRNAs. To reach this aim, the miRNAs were overexpressed in Arabidopsis thaliana by transformation with the corresponding precursor under the control of a strong constitutive promoter. Also, plants were transformed with target genes containing silent mutations that make them resistant to the miRNA. Finally, the macroscopical and molecular phenotypes of these transgenic plants are evaluated to get insights into the regulated biological pathways. The role of several miRNAs in plant development will be discussed.