Abstract: The invention relates to a transitory expression system of recombinant proteins in a plant, characterized in that it comprises a viral expression vector comprising a ubiquitous constitutive promoter upstream from a gene of interest or a reporter gene placed downstream from the viral vector or a gene that is adapted for expression of eucaryotic genes or a construction that comprises a gene of interest placed downstream from a constitutive promoter, wherein said constructions are complemented by a construction which also comprises the gene P1 which is placed downstream from the ubiquitous constitutive promoter and which suppresses the silencing of the virus of the yellow variegation of rice (RYMV, Rice Yellow Mottle Virus). Application: production of proteins of therapeutic interest.