Résumé
RNA polymerase IV and V are principal players in the RdDM pathway, where their current study has shown interaction of several factors that control DNA silencing of intergenic regions and siRNA production. DNA silencing is an important process during cell differentiation, nuclear structure and viral control. However, RNA pol IV and V are yet to be study in model monocot systems like Oryza sativa that can provide further information on genetic silence mechanism in plats. We show the expression pattern of these polymerases in tissues extracts of Oryza sativa. Detectable amounts of these polymerases are found in specific adult plant tissues and particularly expressed during somatic embryogenesis but not during early stages of normal embryo development. The use of synthetic auxin leads to an induction of both RNA pol IV and V in scutellum tissue where nuclear localization may be required for genome reorganization and gene silencing.