Abstract: The present invention provides a method for inducing or enhancing resistance in plants by supplying to the plant a virally encoded booster sequence comprising the 5′ proximal region of the potyvirus genome or by supplying other sequences encoding suppressors of gene silencing alone or in combination. Supplying the booster sequence to a plant, by means of stable transformation into the genome of the plant or introduced by expression from a plant viral expression vector, induces or enhances resistance in a plant against a broad range of pathogens, including viral, fungal and bacterial infectious agents.

Abstract: The present invention provides a method for enhancing the expression of genes in plants by supplying a virally encoded booster sequence comprising the 5' proximal region of the potyvirus genome to the plant. The booster sequence enhances the expression of foreign genes or endogenous plant genes in plants by employing any known methodology of expressing introduced genes in plants. The booster sequence may be used to enhance expression of any gene, including foreign genes or endogenous plant genes, introduced by means of stable transformation into the genome of the plant or introduced by expression from a plant viral expression vector.