MEC BMC2003-09763, 2003-2006

Principal Investigator: Maria Rosa Ponce.
Investigators: Verónica Aguilera Díaz.
Instituto de Bioingeniería. Universidad Miguel Hernández.

Genetic dissection of the role of postranscriptional gene silencing in the control of development in Arabidopsis thaliana

Post-transcriptional gene silencing (PTGS) via small RNA molecules is a recent addition to the inventory of the mechanisms of regulation of gene expression acting as developmental controls. PTGS involves an apparently complex machinery, which degrades the mRNAs for some transcription factors, modulating in this way their intracellular concentration and in turn their temporal and spatial expression patterns.

Mutations in some genes involved in the machinery of PTGS, such as ARGONAUTE1 (AGO1) in Arabidopsis thaliana, cause pleiotropic phenotypes that seem to correspond to the perturbation of several developmental processes in this plant species. We isolated novel alleles of AGO1 that were used to obtain double mutants displaying synergistic phenotypes, which suggests a functional relationship between the mutations involved.

We aim in this project (a) to determine the molecular nature of some genes whose alleles yield phenotypic synergy in double mutants involving AGO1 alleles, and (b) to mutagenize a homozygous ago1/ago1 line aiming to isolate novel mutations that substantially modify its phenotype, to eventually identify the corresponding genes. It is likely that the genes of Arabidopsis thaliana that we expect to identify by following this approach will be elements of the PTGS machinery or will be regulated by PTGS.