Patent ID: 8597950

Claim:
A system for replicating or for replicating and expressing a sequence of interest in a plant, comprising: (i) a DNA precursor of an RNA replicon, said RNA replicon derived from a tobamovirus and comprising at least one sequence of interest, said DNA precursor of said RNA replicon containing in a tobamoviral replicase open reading frame (ORF) or in a tobamoviral movement protein ORF of said RNA replicon, one or more introns inserted within A/U rich localities of said tobamoviral replicase ORF or said tobamoviral movement protein ORF; and (ii) a DNA precursor of a helper replicon, wherein said helper replicon is (a) incapable of systemic movement in a plant both in the presence and in the absence of said RNA replicon (i) and (b) capable of expressing in a plant or more proteins necessary for systemic movement of said RNA replicon (i), whereby said RNA replicon (i) is capable of replication or of replicating and expressing said sequence of interest in a plant, but unable to move systemically in a plant in the absence of said one or more proteins expressed by said helper replicon (ii).